St. Petersburg State University
12th International Conference and School
“PROBLEMS OF GEOCOSMOS”
Book of Abstracts
St. Petersburg, Petrodvorets, October 8–12, 2018
St. Petersburg
2018
Chairman:
Prof. V.S. Semenov St. Petersburg State University, Russia
Vice-chairman:
Dr. S.V. Apatenkov St. Petersburg State University, Russia
Organizing Committee:
Dr. N.Yu. Bobrov,. St. Petersburg State University, Russia Dr. V.V. Karpinsky, St. Petersburg State University, Russia Dr. M.V. Kubyshkina, St. Petersburg State University, Russia Dr. T.A. Kudryavtseva, St. Petersburg State University, Russia Dr. E.L. Lyskova, St. Petersburg State University, Russia N.P. Legenkova, St. Petersburg State University, Russia Dr. I.A. Mironova, St. Petersburg State University, Russia M.V. Riabova, St. Petersburg State University, Russia R.V. Smirnova, St. Petersburg State University, Russia
Program Committee:
Dr. A.V. Divin, St. Petersburg State University, Russia Prof. I.N. Eltsov, Institute of Petroleum Geology and Geophysics SB RAS, Russia Prof. N.V. Erkaev, Institute of Computational Modelling SB RAS, Russia Prof. B.M. Kashtan, St. Petersburg State University, Russia Dr. P.V. Kharitonskii, St. Petersburg State University, Russia Prof. Yu.A. Kopytenko, SPbF IZMIRAN, Russia Dr. A.A. Kosterov, St. Petersburg State University, Russia Dr. V.E. Pavlov, Schmidt Institute of Physics of the Earth, RAS, Russia Prof. V.N. Troyan, St. Petersburg State University, Russia Prof. V.A. Sergeev, St. Petersburg State University, Russia Dr. E.S. Sergienko, St. Petersburg State University, Russia Dr. N.A. Tsyganenko, St. Petersburg State University, Russia Prof. T.B. Yanovskaya, St. Petersburg State University, Russia Dr. N.V. Zolotova, St. Petersburg State University, Russia
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CONTENTS
SECTION EG. EXPLORATION AND ENVIRONMENTAL GEOPHYSICS ...... 25
Conveners - Dr. N.Y.Bobrov, Dr. A.K.Saraev ...... 25
STRUCTURE OF THE NORTHERN PART OF SOUTH-ONEGA SYNCLINE BASING ON AMT, GRAVITY AND MAGNETOMETRY DATA ...... 25
K.Antashchuk1, K.Stepanov2, A.Saraev1...... 25
BASIC 3-D GEOELECTRIC MODEL OF THE LITHOSPHERE OF BELARUS ...... 26
Astapenko V.N., Dubanevich M.A...... 26
TRANSIENT ELECTROMAGNETIC SOUNDINGS OF MAGNETICALLY VISCOUS ROCKS IN THE ZHAMANSHIN IMPACT CRATER ...... 26
Bobrov N.Yu...... 26
RECENT RESEARCH OF GEOPHYSICAL PARAMETERS OF THE LITHOSPHERE PLATFORM REGIONS ...... 27
Burakhovych T.K, Kushnir A.N., Tsvetkova T.A...... 27
RESEARCHING OF PHYSICO-CHEMICAL PROPERTIES OF RESEVOIR FLUIDS BY NMR- RELAXOMETRY METHOD ...... 28
E.S.Chernova1, M.Y.Shumskayte2 ...... 28
NEW MAGNETOTELLURIC STUDY OF THE DEEP STRUCTURE OF THE SOUTH- WESTERN CRIMEA ...... 29
Desyatov D.O.1, Pushkarev P.Yu.1, Rokityansky I.I.2, Stafeev A.N.1, Yakovlev A.G.1,3 ...... 29
THE FEATURES OF DEAD BAND AMT SIGNAL IN CHUKOTKA REGION ...... 29
THE WAY OF THE HOST MEDIUM INFLUENCE CORRECTION IN THE EXPRESS- INTERPRETATION OF 2D MAGNETOVARIATIONAL ANOMALIES ...... 30
E.Ermolin1, O.Ingerov2 ...... 30
DISTORTION OF LOCAL MAGNETOVARIATIONAL ANOMALIES BY EFFECT OF REGIONAL STRUCTURES ...... 30
E.Ermolin1, O.Ingerov2 ...... 30
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ANALYSIS OF THE EFFECT OF ENVIRONMENTAL FACTORS ON THE DISEASE INCIDENCE OF PETROZAVODSK RESIDENTS, BASED ON EMERGENCY CALL DATA ...... 31
Gerasimova А.А., Belashev B.Z., Krutskikh N.V...... 31
THE EXPERIENCE OF LOW-ALTITUDE MAGNETIC SURVEY USING UNMANNED COMPLEX GEOSCAN 401 ...... 32
Goglev D.A., D.J. Capstan, Tsirel V.S...... 32
ON NECESSITY OF GEOLOGICAL ENVIRONMENT MODEL COMPLICATION FOR MONITORING ITS STATE AND FORECAST ITS STABILITY ...... 33
Hachay O.1, Khachay O.2, Khachay A.2 ...... 33
NATURAL ULF PERTURBATIONS OF THE ELECTRIC FIELD IN COASTAL ZONES ...... 34
Ismagilov V.S., Kopytenko Yu.A...... 34
DEEP MAGNETOTELLURIC SOUNDING OF THE NORTHERN PART OF THE SCYTHIAN PLATE...... 34
Kushnir A.N.1, Bryashko N.V.2 ...... 34
MT/MV STUDIES OF THE KIROVOGRAD ANOMALY OF ELECTRIC CONDUCTIVITY IN THE SOUTHERN OF THE DENIPER-DONETSK BASIN SLOPE ...... 35
Kushnir A.N., Burakhovych T.K, Ilyenko V.A...... 35
DEEP ELECTRIC CONDUCTIVITY OF THE AVACHA-KORYAKSKIY GROUP OF VOLCANOES, KAMCHATKA ...... 36
Yu. F. Moroz1,2, V.A. Loginov1 ...... 36
PECULIARITIES IN GEOELECTRICAL STRUCTURE OF KAMCHATKA EAST COAST ...... 37
Moroz Yu.F.1,2, Samoylova O.M.1 ...... 37
DEEP GEOPHYSICAL MODEL OF THE AREA BETWEEN SHANUCH COPPER-NICKEL DEPOSIT AND AGINSKOYE GOLD DEPOSIT IN KAMCHATKA ...... 37
Moroz U.F., Ulybyshev I.S...... 37
THE INFLUENCE OF THE DAILY TEMPERATURE ON RESISTIVITY OF SULFIDE MINE TAILINGS ...... 38
Osipova P.S., Olenchenko V.V., Bortnikova S.B., Yurkevich N.V...... 38
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ABOUT MEASUREMENT OF VERTICAL COMPONENT OF ELECTRIC FIELD AT MAGNETOTELLURIC SOUNDING ...... 39
Plotkin V.V., Mogilatov V.S...... 39
ABOUT THE ROLE OF THE HALL EFFECT AT MAGNETOTELLURIC SOUNDING ...... 40
Plotkin V.V., Mogilatov V.S...... 40
INFLUENCE OF MOSCOW MEGACITY ON NEAR-SURFACE ELECTRIC FIELD VARIATIONS ...... 40
Riabova S.A., Spivak A.A...... 40
FEYNMAN CORRECTIVE ELECTRICAL FIELD ...... 41
B.G. Sapozhnikov ...... 41
INFLUENCE OF DISPLACEMENT CURRENTS ON THE RESULTS OF FREQUENCY SOUNDINGS ON THE EXAMPLE OF THE RESULTS OF THE EXPERIMENT "KOVDOR 2015" ...... 41
Shevtsov A.N...... 41
THE SOLUTION OF THE 2-DIMENSIONAL INVERSE MESD PROBLEM ON THE SELIVANOV-HIITOLA-SORTAVALA-SUISTAMO (NORTHERN LADOGA) ...... 42
Shevtsov A.N., Kolesnikov V.E...... 42
SEISMOACOUSTIC TOMOGRAPHY ON JET GROUTING ...... 43
Shmurak Denis1, Shishkina Mary2 ...... 43
2D MODELING OF AMT DATA ON THE LADOGA AND PECHENGA STRUCTURES...... 43
Skorokhodov A.A...... 43
ON THE NATURE OF THE LADOGA CONDUCTION ANOMALY - GRAPHITES AND (OR) FLUIDS? ...... 44
Zhamaletdinov A.A1,2, Sokolova E.Yu.3,4, LADOGA Working Group ...... 44
LITHOSPERIC CURRENT SOURCES AND THEIR IMPACT ON POWER GRIDS ...... 44
Vakhnina V.V., Gorokhov I.V...... 44
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INVESTIGATION OF SIGNALS OF GEOACOUSTIC EMISSIONS AND ELECTROMAGNETIC RADIATION IN EXPLORATION AND DEEP WELLS ...... 45
Alexey Vdovin, Yurie Astrakhantsev, Nadejda Beloglasova and Evgenia Bajenova ...... 45
POSSIBILITIES OF THREE–COMPONENT GEOACOUSTIC LOGGING AT HYDROCARBON DEPOSITS ...... 46
Alexey Vdovin, Nadejda Beloglasova, Yurie Astrakhantsev and Evgenia Bajenova ...... 46
STATISTICAL RELATIONSHIPS BETWEEN VARIATIONS OF THE GEOMAGNETIC FIELD, AURORAL ELECTROJET, AND GEOMAGNE-TICALLY INDUCED CURRENTS ...... 47
A.V. Vorobev1, V.A. Pilipenko2,3, Ya.A. Sakharov4, V.N. Selivanov5 ...... 47
ABOUT THE INFLUENCE OF GEOMAGNETIC ACTIVITY ON METROLOGICAL CHARACTERIS-TICS OF MAGNETIC INCLINOMETRIC SYSTEMS ...... 48
Vorobeva G.R., Vorobev A.V...... 48
SAMOYLOVSKY ISLAND - NEW INTERNATIONAL POLAR RESEARCH STATION; FIVE YEARS UNDER OPERATION OF IPGG ...... 49
Igor Yeltsov ...... 49
JOINT INTERPRETATION OF GEOPHYSICAL AND GEOCHEMICAL FIELDS BASED ON THEIR ANALYTICAL CONTINUATION DOWN...... 50
Ermokhin Konstantin M1, Zhdanova Ludmila A.2 ...... 50
EXPERIMENTAL VERIFICATION OF METHOD FOR MEASURING THE EFFECTS OF INDUCED POLARIZATION OF DEEP OBJECTS IN NATURAL ELECTROMAGNETIC FIELDS ...... 51
Ermokhin K.M., Kopytenko Yu.A., Petrishchev M.S., Sergushin P.A...... 51
ON THE BOUNDARY BETWEEN THE BRITTLE AND DUCTILE PARTS OF THE EARTH'S CRUST ...... 52
Zhamaletdinov A.A.1,2 ...... 52
EXPERIMENT "MURMAN-2018" ON THE STUDY OF THE DEEP GEOELECTRIC BOUNDARIES IN THE EARTH'S CRUST WITH THE USE OF DC AND INDUCTION SOUNDING METHODS ...... 52
Zhamaletdinov AA1,2,3, Shevtsov AN1, Skorokhodov AA1, Kolobov VV3, Ivonin V.V.3 ...... 52
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NEW DATA ON THE NATURE AND STRUCTURE OF THE LADOGA ANOMALY FROM DC AND AMT RESEARCH ...... 53
Zhamaletdinov A.A.1,2, Shevtsov A.N. 2, Skorohodov A.A.2, Kolesnikov V.Ye.2, Nilov M.Yu.3 ...... 53
SECTION P. PALEOMAGNETISM AND ROCK MAGNETISM ...... 54
Conveners - Dr. P.V. Kharitonskii, Dr. A.A. Kosterov, Dr. E.S. Sergienko ...... 54
INFLUENCE OF STRESS’ MATRIX ON THE INCLUSION DEFORMATION...... 54
Afremov L.L., Anisimov S.V...... 54
MAGNETIC MINERALOGY OF SAMPLES WITH L-SHAPED ARAI-NAGATA DIAGRAMS ..56
Aphinogenova N.A., Smirnov M.A., Gribov S.K...... 56
CHARACTERISTICS OF THE MAGNETIC SUSCEPTIBILITY OF SPIN GLASSES ...... 57
Belokon V.I., Chibiryak E.V, Trofimov A.N, Dyachenko O.I...... 57
FIRST MAGNETOSTRATIGRAPHIC DATA ON THE UPPER CAMBRIAN OF THE KEY SECTION OF THE CHOPKO RIVER (NW SIBERIAN PLATFORM) ...... 58
Chmerev V.S., Pavlov V.E., Rudko D.V...... 58
THE FIRST PALEOMAGNETIC AND PETROMAGNETIC DATA OF TAKYR DEPOSITS IN WEST TURKMENISTAN ...... 58
Elena Degtyareva ...... 58
THE SUBDUCTION ZONES EFFECT ON THE STRUCTURE OF THE SMALL-SCALE CURRENTS AT CORE-MANTLE BOUNDARY ...... 59
Demina I., Gorshkova N., Ivanov S., Merkuryev S...... 59
INTERPRETATION OF MAGNETIC ANOMALIES IN CONDITIONS OF PRESENCE OF RESIDUAL MAGNETIZATION AND OTHER COMPLICATIONS ...... 60
Konstantin M. Ermokhin ...... 60
MAGNETIC PROPERTIES OF SOILS FROM THE VOLGA-KAMA FOREST-STEPPE ...... 60
L.A. Fattakhova, L.R. Kosareva, A.A. Shinkarev ...... 60
TECTONIC AND GEOLOGICAL RESTRICTIONS ON DEVELOPING APWP FOR NORTH EURASIAN PLATE IN PERMIAN TIME ...... 61
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Fedyukin I.V...... 61
THE RESEARCH WAS SUPPORTED BY GRANT OF THE GOVERNMENT OF THE RUSSIAN FEDERATION NO. 14.Z50.31.0017...... 61
ANALOGUE OF THE NEDUBROVO ANOMALOUS REMANENCE IN THE ZHUKOV RAVINE SECTION, RUSSIAN BASIN: THE EVIDENCE FOR UNUSUAL BEHAVIOR OF GEOMAGNETIC FIELD BEFORE PERMIAN-TRIASSIC BOUNDARY ...... 62
RATE AND FREQUENCY OF EXTREME GEOMAGNETIC FIELD INTENSITY VARIATIONS ...... 63
Yves Gallet1, Stanislava Yutsis-Akimova1,2, Alexandre Fournier1, Agnès Genevey3, Marie Troyano1, Phil Livermore4, Maxime Le Goff1, Michel Fortin5, Shahrmardan Amirov6 ...... 63
THE UPPER CRETACEOUS PALEOMAGNETIC INVESTIGATION OF NORTHEAST OF WESTERN SIBERIA ...... 64
Gnibidenko Z.N.1, Levicheva A.V.1, Semakov N.N.1, Marinov V.A.2 ...... 64
PALEOMAGNETISM OF PALEOZOIC ROCKS OF THE EASTERN SLOPE OF THE SOUTH URALS ...... 64
Golovanova I.V., Danukalov K.N., Kosarev A.M., Sal’manova R.Yu...... 64
PALEOMAGNETISM OF ORDOVICIAN-SILURIAN VOLCANIC ROCKS ON THE WESTERN SLOPE OF THE SOUTH URALS ...... 65
Golovanova I.V., Danukalov K.N., Sergeeva N.D., Sal’manova R.Yu., Khatapov S.S...... 65
LABORATORY MODELING OF THELLIER-COE PALEOINTENSITY DETERMINATIONS ON ROCKS BEARING TCRM ...... 66
Gribov S.K.1, Shcherbakov V.P.1,2,3, Aphinogenova N.A.1, Smirnov M.A.1 ...... 66
PRELIMINARY COMPOSITE MAGNETOSTRATIGRAPHIC SECTION OF THE VALANZHINIAN OF THE CRIMEAN MOUNTAINS ...... 66
Grishchenko V.A., Guzhikov A.Yu., Manikin A.G...... 66
UPPER CRETACEOUS MAGNETOSTRATIGRAPHY OF LOWER VOLGA REGION ...... 67
Guzhikova A.A., Guzhikov A.Yu., Manikin A.G., Grishchenko V.A...... 67
ESTIMATION OF THE POSITION OF ARCH. NOVAYA ZEMLYA AT THE PERMIAN TIME ACCORDING TO PALEOMAGNETIC DATA ...... 68
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Iosifidi A. G.1,2 ...... 68
PALEOMAGNETIC STUDIES OF CARBONIFEROUS DEPOSITS OF THE RUSSIAN PLATFORM ...... 69
Iosifidi A. G.1,2, Sergienko E. S.3, Salnaia N. V.4, Otmas N. M.1, Zuravlev A. V.5, Mikhailova V. A.1, Popov V. V.1,3, Danilova A. V.1 ...... 69
EXPLORING THE INFLUENCE OF THE GEOMAGNETIC POLARITY TIME SCALE ON RESULTS OF THE GEOCHRONOLOGICAL AND GEOHISTORICAL ANALYSIS OF THE MARINE MAGNETIC ANOMALIES ...... 70
S. A. Ivanov1 and S. A. Merkuryev1,2 ...... 70
THE AGGREGATION OF SUPERPARAMAGNETIC PARTICLES UNDER IN-PHASE AND ANTIPHASE OSCILLATIONS OF THEIR MAGNETIC MOMENTS ...... 71
Karimov F.H...... 71
ROCK-MAGNETIC AND GRAIN SIZE DATA ON THE QUATERNARY MULTI-LAYERED KEY SECTION TOLOGOY (BURYATIA, RUSSIA) ...... 72
Kazansky A.Yu.1,2, Matasova G.G.3, Shchetnikov A. A.4, 5, 6, Filinov I. A.4,5,6 ...... 72
MAGNETIC PROPERTIES OF BRICKS: SUPERPARAMAGNETISM AND PRESENCE OF HIGH-COERCIVITY-LOW-UNBLOCKING-TEMPERATURE MAGNETIC PHASE ...... 73
P.V. Kharitonskii1, A. Kosterov2, I.M. Berestnev2, E.S. Sergienko2 ...... 73
PETROMAGNETIC LEGEND OF THE BASIS OF THE EASTERN BOARD OF THE TUNGUS SYNECLISE (WORKING OPTION) ...... 74
Alexander A. Kirguev1, Konstantin M. Konstantinov1,2, Alexanderа E. Vasilyeva3 ...... 74
PETRO- AND PALEOMAGNETIC CHARACTERISTICS OF KIMBERLITES AND BASITES IN THE KYUTINGDE GRABEN (NORTHEASTERN SIBERIAN PLATFORM)...... 75
Innokentiy K. Konstantinov1, Konstantin M. Konstantinov1,2, Mikhail D. Tomshin3, Dimitri P. Gladkochub1, Andrey A. Jakovlev2, Alexandra E. Vasil’eva3...... 75
PALEOMAGNETIC CHARACTERISTICS OF DOLERITE DYKES OF THE VILUY-MARKHA FAULT ZONE (YAKUT DIAMONDIFEROUS PROVINCE) ...... 76
Konstantin M. Konstantinov1,2, Shamil Z. Ibragimov3, Innokentiy K. Konstantinov2, Alexander A. Kirguev1, Mikhail D. Tomshin4, ...... 76
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PALEOMAGNETISM OF DOLERITE DIKES OF THE CHARA-SINSK FAULT ZONE (ALDAN BLOCK OF THE SIBERIAN PLATFORM) ...... 77
Konstantin M. Konstantinov1,2, Innokentiy K. Konstantinov2, Shamil Z. Ibragimov3, Mikhail D. Tomshin4, Andrey A. Jakovlev1 ...... 77
THE MAGNETIC PROPERTIES OF LAKE TURGOYAK SEDIMENTS (CHELYABINSK REGION, RUSSIA) ...... 78
L. Kosareva 1, D. Nurgaliev 1, P. Krylov 1, D. Kuzina 1, V. Antonenko 1, A. Yusupova 1, V. Vorob’ev 2, V. Evtygin 2 .. 78
HIGH-FIELD HYSTERESIS AND LOW-TEMPERATURE MAGNETIC PROPERTIES OF HEMATITE- AND GOETHITE-BEARING SEDIMENTS ...... 78
A. Kosterov1, E. Sergienko1, A. Iosifidi2,3, S. Yanson1 ...... 78
PALEOMAGNETISM OF PHANEROZOIC GEOLOGICAL COMPLEXES OF MONGOLIA AND TUVA ...... 79
D.V. Kovalenko ...... 79
RHYTHMS OF THE PALEOINTENSITY CHANGES WITH CHARACTERISTIC TIMES 5 AND 1 MA ...... 80
A.Yu. Kurazhkovskii, N.A.Kurazhkovskaya, B.I.Klain ...... 80
EARTH’S CRATER MAGNETIC ANOMALIES: NUMERICAL MODELING OF SIMPLE CRATERS ...... 81
M. Yu. Kuzmicheva ...... 81
ANISOTROPY OF MAGNETIC SUSCEPTIBILITY IN THE PERMIAN-TRIASSIC INTRUSIONS FROM THE NORTHWESTERN SIBERIAN PLATFORM: IMPLICATIONS FOR THE MAGMA TRANSPORT PATTERNS ...... 82
Latyshev A.V.1,2, Ulyahina P.S.2, Krivolutskaya N.A.3 ...... 82
PALEOPROTEROZOIC TRENDS OF REMAGNETIZATION FOR THE KARELIAN CRATON: MYTH OR REALITY ...... 83
Lubnina N.V., Tarasov N.A., Zakharov V.S...... 83
KEY EARLY PALEOPROTEOROZOIC 2.45 GA PALEOMAGNETIC POLE FOR THE KARELIAN CRATON: FURTHER PALEOMAGNETIC EVIDENCE ...... 84
Lubnina N.V., Tarasov N.A...... 84
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EXPERIMENTAL MODELING OF CHEMICAL MAGNETIZATION IN OCEANIC BASALTS AND ITS PROPERTIES ...... 84
Maksimochkin V.I., Grachev R.A., Tselebrovskiy A.N...... 84
DETERMINATION OF PALEOINTENSITY OF GEOMAGNETIC FIELD ON THE VOLCANOES LAVAS OF KAMCHATKA ...... 85
V.I. Maksimochkin1), Yu.V. Sleptsova1), A.N. Nekrasov2) ...... 85
INTERRELATIONS BETWEEN THE GRANULOMETRIC COMPOSITION, MAGNETIC PROPERTIES AND GEOCHEMICAL INDICATORS IN THE SUBAERIAL DEPOSITS OF THE ARCHAEOLOGICAL SITE "TUYANA" (TUNKA DEPRESSION, BAIKAL REGION, RUSSIA) ...... 86
Matasova G.G.1, Shchetnikov A. A.2,3,4, Kazansky A.Yu.5,6, Filinov I. A.2,3,4 ...... 86
PRELIMINARY ESTIMATION OF THE NON-DIPOLE PART OF THE GEOMAGNETIC FIELD IN THE QUATERNARY PERIOD BASED ON THE INVESTIGATION OF MARINE MAGNETIC ANOMALIES ON THE CARLSBERG RIDGE ...... 87
Merkuriev S.A.1,2, Demina I.M.1, Ivanov S.A.1 ...... 87
METHODOLOGY FOR LOW FLYING AEROMAGNETIC SERVICE WITH THE USE OF UAV ...... 89
Parshin A.V.1, Tsirel V.S.2, Rzhevskaya A.K.3 ...... 89
PALEOMAGNETISM OF THE UDZHA AND OLENEK UPLIFTS, NORTHERN SIBERIA ...... 90
Pasenko A.M.1, Malyshev S.V.2 ...... 90
METALLIC IRON IN BASALTIC LAVA RIVER FROM MALY YENISEI (TUVA, RUSSIA): THE RESULTS OF THERMOMAGNETIC STUDY ...... 91
Pechersky D.M.1, Kazansky A.Yu.2, 3, Kozlovskiy A.M.4, Kuzina D.M.5, Markov G.P.1 ...... 91
THE AVERAGE SIZE OF IRON PARTICLES VS. THE AGES OF LUNAR BASALTS ...... 92
D.M. Pechersky, G.P. Markov ...... 92
PETROMAGNETIC AND MICROPROBE STUDIES OF PEAT DEPOSITS (PRELIMINARY RESULTS) ...... 93
Peskov A.Yu.1, Chakov V.V.2, Klimin M.A.2, Krutikova V.О.1, Zakharchenko Е.N.2, Arkhipov М.V.1, Didenko А.N.1,3 ...... 93
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PALEOMAGNETISM OF THE PIONERSKAYA FORMATION; CONTRIBUTION TO THE GEODYNAMIC MODEL OF THE SIKHOTE-ALIN OROGENIC BELT ...... 94
Peskov А.Yu.1, Arkhipov M.V.1, Kudymov A.V.1, Didenko A.N.1, 2 ...... 94
MAGNETIC PROPERTIES OF SEDIMENTARY ROCKS FROM PIONERSKAYA AND GORINSKAYA FORMATIONS (JUNCTION ZONE BETWEEN THE SIKHOTE-ALIN AND MONGOL-OKHOTSK OROGENIC BELTS) ...... 94
Peskov A.Yu...... 94
IDENTIFICATION OF MAGNETIC CHRONS BY COMPONENTS OF MARINE BAND ANOMALIES ...... 95
A.A.Petrova, Yu.A.Kopytenko ...... 95
ARHEOMAGNETIC STUDIES OF NEOLITHIC CERAMICS OF VEKSA ARCHEOLOGICAL SITE (CONTINUATION) ...... 96
Pilipenko O.V., Nachasova I.E., Markov G.P...... 96
NEOPROTEROZOIC GLACIAL DEPOSITS OF SIBERIA: THE PROS AND CONS OF SNOWBALL EARTH HYPOTHESIS ...... 97
Andrey Shatsillo1, Dmitriy Rudko1, Sergey Rudko2,3, Irina Latysheva2, Nikolay Kuznetsov2 ...... 97
CYCLOSTRATIGRAPHIC ANALYSIS OF LOPATA FORMATION (NE OF ENISEY RIDGE, WESTERN SIBERIAN PLATFORM): MORE ON HYPERACTIVITY OF GEOMAGNETIC FIELD IN THE LATE PRECAMBRIAN ...... 97
Dmitriy Rudko1, Sergey Rudko2, Andrey Shatsillo1, Nikolay Kuznetsov2 ...... 97
BERYLLIUM AND RELATIVE PALEOINTENSITY SIGNALS DURING THE LAST GEOMAGNETIC REVERSAL ...... 98
Tatiana Savranskaia1, Jean-Pierre Valet1, Laure Meynadier1, Franck Bassinot2, Quentin Simon3, Didier Bourlès3, Nicolas Thouveny3 ...... 98
APPLYING THE MAGNETIC FORCE MICROSCOPY TO EVALUATE THE MAGNETIC STATES IN ROCKS ...... 99
E.S. Sergienko1, S.Yu. Yanson1, I.A. Vasilyeva1, M.S. Lozhkin1, A. Kosterov1, P.V. Kharitonskii2 ...... 99
NEW 1.86 GA PALEOINTENSITY DATA FROM THE KOLA PENINSULA INTRUSIONS, NE FENNOSCANDIA ...... 100
Shcherbakova V.V.1, Veselovskiy R.V.2,3, Shcherbakov V.P.1, Zhidkov G.V.1, Smirnov M.A.1 ...... 100 12
PARADOXES IN THE LATITUDE DISTRIBUTION OF THE GEOMAGNETIC FIELD VECTOR IN THE BRUNHES CHRON ...... 101
Shcherbakov, V.P.1,2,3, Khokhlov, A.V.2,4, Sycheva, N.K.1 ...... 101
CHECKING THE DIMENSIONS OF COULOMB'S LAW FOR STATIONARY MAGNETIC FIELD AND THE DETERMINATION OF THE DISTANCES TO THE ELEMENTARY SOURCES IN MAGNETOMETRY ...... 101
Sorokin A.G...... 101
ANALYTIC SCALING LAWS IN PLANETARY DYNAMO MODELS ...... 102
Starchenko S.V...... 102
VARIATIONS OF ENERGY AND POWER FOR A POTENTIAL GEOMAGNETIC FIELD SINCE 1840 ...... 103
S.V. Starchenko and S.V. Yakovleva ...... 103
RECONSTRUCTION OF JURASSIC SEDIMENTARY ENVIRONMENTS USING ROCK- MAGNETIC DATA IN THE MIKHAYLOVTSEMENT REFERENCE SECTION (RYAZAN REGION, RUSSIA) ...... 104
Stepanov I.A.1, Kazansky A.Yu.1,2, Kosareva L.R.3, Rogov M.A.2, Tesakova E.M.1,2, Shchepetova E.V.2 ...... 104
СOMPUTER MODELING OF THELLIER AND WILSON METHODS ON SD GRAINS CARRYING TRM AND CRM ...... 105
Sycheva, N.K.1, Shcherbakov, V.P.1,2 ...... 105
MORPHOLOGY AND COMPOSITION OF FOSSIL COSMIC DUST FROM VARIOUS SOURCES ...... 106
Tselmovich V.A.1, Kuzina D.M.2, Nourgaliev D.K.2, Garin E.V.3. Philippov D.A.3 ...... 106
THE POSSIBILITY OF DETERMINING THE AGE OF THE NORASHEN SECTION OF LAKE SEVAN ...... 107
A.A. Vardanyan, R.Y. Stakhovskaya ...... 107
ESTIMATION OF SUITABILITY OF SEDIMENTS OF THE SECTION OF DZKNAGNET RIVER FOR STUDYING THE FINE STRUCTURE OF GEOMAGNETIC FIELD ...... 108
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FOUR INDEPENDENT ISOTOPIC GEOCHROMETERS IN PALEOPROTEROZOIC DOLERITES FROM THE KOLA PENINSULA AS THE BASIS FOR THE NEW ~1.86 GA FENNOSCANDIAN KEY PALEOMAGNETIC POLE ...... 109
Veselovskiy R.V.1,2,3, Samsonov A.V.3, Stepanova A.V.4, Sal’nikova E.B.5, Larionova Yu.O.3, Travin A.V.6, Arzamastsev A.A.5, Egorova S.V.4, Erofeeva K.G.3, Stifeeva M.V.5, Esenkov A.A.1, Chistyakova A.V.1 ...... 109
ROCK MAGNETISM AND PALEOMAGNETISM OF THE EDIACARAN SEDIMENTS OF THE YENISEI RIDGE VOROGOVKA SERIES ...... 110
E.V. Vinogradov, D.V. Metelkin, V.V. Abashev ...... 110
DATE OF TRM OF GRANITE BATHOLITH: IS IT POSSIBLE? ...... 111
Vodovozov V.Yu.1,2, Zakharov V.S.1, Zverev A.R.1,2, Travin A.V.3 ...... 111
CORRECTION FOR A WEAK RESIDUAL MAGNETIC FIELD IN THE FURNACE DURING THE PALEOINTENSITY DETERMINATION BY THELLIER-COE METHOD ...... 111
Zhidkov G.V...... 111
PALEOMAGNETISM OF THE EARLY PROTEROZOIC BASITE COMPLEXES OF THE OLEKMA BLOCK OF THE SOUTH OF THE SIBERIAN CRATON ...... 112
Zverev A.R.1,2, Vodovozov V.Yu.1,2 ...... 112
SECTION S. SEISMOLOGY ...... 114
Conveners - Prof. T.B. Yanovskaya, Prof. V.N. Troyan ...... 114
TECTONIC PLATES MICROMOTIONS CAUSED BY THE CHANDLER WOBBLE ...... 114
Blagoveshchenskaya Elena ...... 114
SHORT-TERM PRECURSORS OF EARTHQUAKES ...... 115
Dovbnya B.V...... 115
NEW DATA ABOUT LOW MAGNITUDE SEISMICITY OF THE GAKKEL RIDGE ON THE DATA OF CONTINUOUS REGIONAL MONITORING ...... 116
Fedorenko I.V...... 116
SEISMICITY AND CRUSTAL STRUCTURE OF THE SOUTHERN CRIMEA AND ADJACENT NORTHERN BLACK SEA FROM LOCAL SEISMIC TOMOGRAPHY ...... 117
Gobarenko V.1, Yegorova T.2 ...... 117
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APPLICATION OF THE RECEIVER FUNCTION TECHNIQUE IN AREAS WITH A LOW- VELOCITY NEAR-SURFACE LAYER ...... 118
Goev A.G.1, Kosarev G.L.2, Sanina I.A.1 ...... 118
HIGH-SENSITIVITY SENSOR FOR CORRECTION OF INSTRUMENTAL THERMAL NOISE OF SEISMIC DEVICES ...... 119
Gravirov V.V. 1, 2, Kislov K.V. 1, Likhodeev D.V.2 ...... 119
PEMSDAS - PORTABLE EXPANDABLE MODULAR SEISMIC DATA ACQUISITION SYSTEM ...... 119
Gravirov V.V. 1, 2, Kislov K.V. 1, Sobisevich A.L. 2, Sobisevich L.E.2 ...... 119
ATLAS OF THE AFTERSHOCKS: TO THE 150TH ANNIVERSARY OF FUSAKICHI OMORI ...... 120
Guglielmi A.V.1, Zotov O.D.2, Zavyalov A.D.1 ...... 120
NEW MACROSEISMIC MANIFESTATIONS OF EARTHQUAKES IN THE VRANCH AREA ON THE TERRITORY OF UKRAINE...... 120
Ilyenko V.A., Kushnir A.N...... 120 [email protected] ...... 120
SOME REMARKS ON THE SEISMOMETRIC EXPERIMENTS TAKING INTO ACCOUNT THE THICKNESS OF THE FROZEN LAYER SOIL ...... 121
Kislov K.V.1, Gravirov V.V.1, 2 ...... 121
ON THE QUESTION OF THE ROTATIONAL SEISMOLOGY ...... 122
Kislov K.V.1, Gravirov V.V.1, 2 ...... 122
SEISMICITY IN THE AREA OF NORTH SEA ROUTE ...... 122
Konechnaya Y.V.1, Fedorenko I.V.2 ...... 122
POSSIBLE SHORT-TERM IONOSPHERIC PRECURSORS OF STRONG CRUSTAL EARTHQUAKES ...... 123
Korsunova L. P.1, Legenka A. D.1, Hegai V. V.1 ...... 123
HETEROGENEITIES OF THE EARTH'S INNER CORE BOUNDARY FROM DIFFERENTIAL MEASUREMENTS OF PKIKP AND PCP SEISMIC PHASES...... 123
Dmitry Krasnoshchekov, Vladimir Ovtchinnikov ...... 123
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RADIAL ANISOTROPY OF THE EUROPEAN UPPER MANTLE FROM RECORDS OF EARTHQUAKES AND SEISMIC NOISE ...... 124
E.L.Lyskova, T.Yu.Koroleva, T.B.Yanovskaya ...... 124
SOFTWARE SERVICE «SEISMOLOGY ONLINE» ...... 125
Mikhailova Yana1, Morozov Alexey2 ...... 125
GEODYNAMICS OF THE EAST-EUROPEAN CRATON BASED ON UP-TO-DATE GNSS DATA ...... 126
A. V. Mokhnatkin1, V. L. Gorshkov1, N. V. Scherbakova1, B. A. Assinovskaya2 ...... 126
NATURAL AND TECHNOGENIC SEISMIC AND GEODYNAMIC ACTIVITY OF THE SOUTHERN URALS ...... 126
Nesterenko M. Yu...... 126
ANALYSIS OF THE SPATIAL DISTRIBUTION OF THE EARTHQUAKE FOCAL MECHANISMS IN THE KURIL-OKHOTSK REGION ...... 127
Polets A.Yu...... 127
FEATURES OF THE TECTONIC STRESS FIELD IN THE OKHOTSK SEA AND JAPANESE REGIONS ...... 128
Polets A.Yu...... 128
SPLITTING OF EARTH'S FUNDAMENTAL SPHEROIDAL MODE 0S2 ...... 129
IN GEOMAGNETIC VARIATIONS ...... 129
Riabova S.A., Spivak A.A...... 129
DEEP VELOCITY SRTUCTURE OF THE ARCTIC REGION FROM RAYLEIGH WAVE DISPERSION DATA ...... 130
Alena Seredkina ...... 130
SUPERDEEP DRILLING AND ITS EFFECT ON THE SEISMIC MODELS OF THE FENNOSCANDIAN SHIELD ...... 130
Sharov N.V...... 130
SELF-SIMILARITY ANALYSIS OF EARTHQUAKES AND ACTIVE FAULTS WITHIN THE SIKHOTE-ALIN OROGENIC BELT AND NEIGHBORING AREAS ...... 131 16
Zakharov V.S. 1,3*, Didenko A. N. 2,4, Gil’manova G.Z. 2, Merkulova T.V. 2 ...... 131
ON THE SPATIAL-TEMPORAL STRUCTURE OF AFTERSHOCK SEQUENCES ...... 132
Zotov O.D.1, Zavyalov A.D.2, Klain B.I.1 ...... 132
STP. SOLAR-TERRESTRIAL PHYSICS ...... 133
Conveners - Dr. N.V.Zolotova, Dr. A.V.Divin ...... 133
EMPIRICAL MAGNETOSPHERIC MODELS FOR SIR- AND CME-DRIVEN MAGNETIC STORMS ...... 133
Andreeva V. A.1, Tsyganenko N. A.1 ...... 133
DEPRESSION OF THE TOTAL FLUX OF SOLAR ELECTROMAGNETIC RADIATION DURING THE GENERATION OF RELATIVISTIC PROTONS OF SOLAR COSMIC RAYS ... 134
Avakyan S.V. 1, Nicvol’skii G.A. 2 ...... 134
HOW DOES THE GEOCOSMOS CONTROL THE BIOSPHERE? FORMATION OF ASSOCIATES IN HIGH DELUTED WATER BIOSOLUTIONS UNDER THE INFLUENCE OF THE MICROWAVE FLUX FROM THE IONOSPHERE ...... 135
Avakyan S.V. 1, Baranova L.A. 2 ...... 135
HOW DOES THE GEOCOSMOS CONTROL THE BIOSPHERE?2. DNA, IONOSPHERIC MICROWAVES AND WATER ...... 136
Avakyan S.V. 1, Baranova L.A. 2 ...... 136
INFLUENCE OF DIFFERENT IONOSPHERIC DISTURBANCES ON THE GPS SCINTILLATIONS AT HIGH LATITUDES ...... 137
V.B. Belakhovsky1, Y. Jin2, W.J. Miloch2 ...... 137
ON THE CORRELATION BETWEEN LOCAL CRUSTAL MAGNETIC FIELD OF THE MOON AND ION REFLECTION ...... 137
R. Belyaev1, A. Divin1, V. Semenov1, I. Zaytsev1 ...... 137
PERSPECTIVES OF MONITORING OF ATMOSPHERIC ELECTRIC FIELD IN THE CENTRAL PART OF KAMCHATKA PENINSULA TO DETECT ATMOSPHERIC-ELECTRIC EFFECTS FROM VOLCANIC ERUPTIONS ...... 138
Cherneva N.V.1, Firstov P.P.1,2, Akbashev R.R.2, Malkin E.I.1 ...... 138
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DEFINITION OF TEMPERATURE AND SONIC SPEED VALUES AT THE MESOSPHERIC HEIGHTS FROM VARIATIONS OF PARTIAL REFLECTION RADAR SIGNALS ...... 139
Cherniakov S.M., Turyansky V. A...... 139
COSMIC RAY CUTOFF RIGIDITY CHANGES CAUSED BY THE DISTURBED GEOMAGNETIC FIELD OF THE STORM IN JUNE 2015 ...... 139
Danilova1 O.A., Tyasto1 M.I., Sdobnov2 V.E...... 139
CONJUGATE GROUND-SPACECRAFT OBSERVATIONS OF VLF CHORUS ELEMENTS ... 140
A. G. Demekhov1,2, J. Manninen3, O. Santolík4.5, E. E. Titova1 ...... 140
YOUNGER DRYAS AND RADIOCARBON DATA ...... 141
Dergachev V.A., Kudryavtsev I.V...... 141
THEMIS AND MAIN CAMERA SYSTEM OBSERVATIONS - A CASE STUDY ...... 141
I.V. Despirak1, T.V. Kozelova1, B.V. Kozelov1, A.A. Liubchich1 ...... 141
COMPARISON OF DIFFERENT LATITUDE SUBSTORMS DURING TWO LARGE MAGNETIC STORMS ...... 142
I.V. Despirak1, N.G. Kleimenova2, V. Guineva3...... 142
ON THE SIMILARITY OF THE SERPENTINE EMISSION SPECTRA AT GEOMAGNETIC POLES ...... 144
B.V. Dovbnya1, B.I. Klain2 ...... 144
STATISTICAL STUDY OF THE EFFECT OF THE SUBSTORM ACTIVITY ON THE FORMATION OF NOISE ULF EMISSIONS IN THE FREQUENCY RANGE (0 – 7) HZ ...... 144
B.V.Dovbnya, B.I.Klain, N.A.Kurazhkovskaya ...... 144
SOME PECULIARITIES OF THE DIURNAL, SEASONAL AND CYCLIC VARIATIONS OF MID-LATITUDE ULF EMISSIONS WITH RESONANCE STRUCTURE OF THE SPECTRUM ...... 145
B.V.Dovbnya, B.I.Klain, N.A.Kurazhkovskaya ...... 145
THE ELECTRON ENERGY SPECTRA ON THE NIGHTSIDE (R = 6-11 RE) DURING GEOMAGNETIC STORMS ...... 146
Dubyagin S.V.1, Ganushkina N. Y.1,2 ...... 146
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ELECTROMAGNETIC FIELDS OF MAGNETOSPHERIC ULF DISTURBANCES IN CONJUGATE IONOSPHERES: CURRENT/VOLTAGE DICHOTOMY ...... 146
ANALYSIS OF CHEMICAL COMPONENTS OF POLAR WINTER ATMOSPHERE DURING RELATIVISTIC ELECTRON PRECIPITATION ...... 147
Golubenko Kseniia1, Mironova Irina1, Rozanov Eugene2, Artamonov Anton3 ...... 147
THE INFLUENCE OF FORESHOCK ORIENTATION ON THE POLAR CUSPS OSCILLATIONS ...... 147
Guglielmi A.V., Kozyreva O.V...... 147
OBSERVATION OF THE PROTON AURORA DYNAMICS AND THE SAR ARC OCCURRENCE AS A CONSEQUENCE OF THE INTENSE CONVECTION AND SUBSTORM ...... 148
Ievenko I.B...... 148
EASTWARD PROPAGATION OF THE PC1 WAVES ALONG THE PLASMAPAUSE ACCORDING TO OBSERVATION OF THE DYNAMICS OF PROTON AURORA AND SAR ARC ...... 148
Ievenko I.B., Parnikov S.G., Baishev D.G...... 148
AN APPROACH TO REGIONAL THREE-DIMENSIONAL MODELLING OF GROUND ELECTROMAGNETIC FIELD VARIATIONS DURING SPACE WEATHER EVENTS USING RESULTS OF MAGNETOHYDRODYNAMIC MODELLING OF THE EARTH’S MAGNETOSPHERE AND IONOSPHERE ...... 149
Elena Ivannikova1,2, Mikhail Kruglyakov1,3, Alexey Kuvshinov1, Lutz Rastätter4, Antti Pulkkinen4 ...... 149
BY IMF AND CLOUD RADIATIVE PROPERTIES AFFECT TO THE POLAR TROPOSPHERIC PRESSURE THROUGH THE IONOSPHERIC POTENTIAL IMPACT TO GEC ...... 150
1 Arseniy Karagodin 1, 2 Mervyn P. Freeman2, 3 Mai Mai Lam2, 4 Eugene Rozanov3, 5 Irina Mironova1...... 150
CHANGES IN THE POSITION OF THE AURORAL OVAL UNDER CONDITIONS OF DISPLACEMENT OF THE EARTH'S MAGNETIC POLE ...... 151
Kopytenko Yu.A.1, Chernous S.A.2 Petrova A.A.1, Filatov M.V.2 Petrishchev M.S.1 ...... 151
ON APPLICATION OF ASYMMETRIC KAN-LIKE EXACT EQUILIBRIA TO THE EARTH MAGNETOTAIL MODELING ...... 151
Daniil B. Korovinskiy1, 2 Darya I. Kubyshkina1, 3 Vladimir S. Semenov2, 4 Marina V. Kubyshkina2, 5 Nikolai V. Erkaev2,3,4, 6 Ivan B. Ivanov5, 7 Stefan A. Kiehas1 ...... 151
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THE DRIFT-COMPRESSION MODES IN THE MAGNETOSPHERIC PLASMA ...... 152
Kostarev D.V.1, Mager P.N.1, Klimushkin D.Yu.1 ...... 152
VIRTUAL MAGNETOGRAMS – NEW TOOL FOR THE STUDY OF SOLAR WIND- MAGNETOSPHERE COUPLING ...... 152
Kozyreva O.V.1, Pilipenko V.A.2, Soloviev A.A.2 ...... 152
INTERMITTENCY STATISTICS OF HIGH-LATITUDE GEOMAGNETIC PULSATIONS PI2 ...... 153
N.A.Kurazhkovskaya, B.I.Klain, I.A.Yelagina ...... 153
EFFECT OF THE SOLAR WIND AND IMF PARAMETERS ON POLARIZATION CHARACTERISTICS OF HIGH-LATITUDE GEOMAGNETIC IMPULSES (MIES) ...... 154
N.A.Kurazhkovskaya, B.I.Klain ...... 154
CONSTRAINING THE EARLY EVOLUTION OF VENUS AND EARTH BY REPRODUCING ELEMNTAL RATIOS ...... 154
Lammer H...... 154
KELVIN-HELMHOLTZ INSTABILITY OF THE LOW-LATITUDE BOUNDARY LAYER OF THE GEOMAGNETIC TAIL ...... 155
Leonovich A.S.1, Kozlov D.A.1 ...... 155
LARGE-SCALE TYPES OF THE SOLAR WIND AND APPEARANCE OF MAGNETIC SUBSTORMS ...... 143
I.V. Despirak1, A.A. Liubchich1, N.G. Kleimenova2 ...... 143
COLLISIONLESS MAGNETIC RECONNECTION: 3D STRUCTURE OF JET FRONTS IN THE PRESENCE OF A GUIDE FIELD ...... 143
A. Divin1, V. Semenov1, I. Zaytsev1 ...... 143
IONOSPHERIC DISTURBANCE CAUSED BY RADIATION OF CHELYABINSK BOLIDE FLIGHT ...... 156
Losseva T.V.1, Golub’ A.P.2, Lyakhov A.N.1, Kosarev I.B.1 ...... 156
SIMULTANEOUS OBSERVATIONS OF A COMPRESSIONAL PC5 WAVE BY EKB RADAR IN THE IONOSPHERE AND BY VAN ALLEN PROBES IN THE MAGNETOSPHERE ...... 157
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Mager O.V., Chelpanov M.A., Mager P.N., Klimushkin D.Yu., Berngardt O.I...... 157
ELEMENTS OF FORECASTING OF SPACE WEATHER AND IONOSPHERIC PARAMETERS ...... 157
Maltseva O.A.1, Bezvytnyj S.A.2, Morozov B.E.2, Shilov D.I.2, Shmelev J.A.2 ...... 157
MODELING AND ANALYSIS OF IONOSPHERIC CRITICAL FREQUENCY DATA ON THE BASIS OF A MULTICOMPONENT MODEL ...... 158
Mandrikova O.V., Fetisova N.V., Polozov Yu.A...... 158
ANALYSIS OF NEUTRON MONITORS DATA DURING THE PERIODS OF HELIOSPHERIC DISTURBANCES ...... 159
Mandrikova O.V., Zalyaev T.L., Mandrikova B.S...... 159
IN SEARCH OF DISTURBANCES OF THE UPPER IONOSPHERE AND GEOMAGNETIC FIELD ABOVE HURRICANES AS OBSERVED BY SWARM SATELLITES ...... 160
1 Martines-Bedenko V.A.1, 2 Pilipenko V.A.1,2, 3 Zakharov V.I.3 ...... 160
NUMERICAL METHODS IN THE PROBLEM OF STUDYING THE EFFECT OF COSMIC RAYS ON THE EARTH'S ATMOSPHERE ...... 160
Maurchev E.A.1, Balabin Yu.V., Gvozdevsky B.V., Mikhalko E.A., Hermanenko A.V., Belakhovsky V.B...... 160
VALIDATION OF THE RESULTS OF MODELING THE PASSAGE OF COSMIC RAYS THROUGH THE EARTH'S ATMOSPHERE BY EXPERIMENTAL DATA ...... 161
Mikhalko E.A. 1, Maurchev E.A., Germanenko A.V., Balabin Yu.V...... 161
A NUMERICAL MODEL OF THE HORIZONTAL AND VERTICAL WIND IN THE EARTH’S ATMOSPHERE AND ITS IMPROVEMENTS ...... 161
Mingalev I.V.1, Orlov K.G.1, Mingalev V.S.1*, Chechetkin V.M.2 , Mingalev O.V.1 ...... 161
СОЛНЕЧНЫЕ ПРОТОННЫЕ СОБЫТИЯ В ПРИРОДНЫХ АРХИВАХ: ПРОБЛЕМЫ ИЗУЧЕНИЯ И ФИЗИЧЕСКИЕ ОГРАНИЧЕНИЯ ...... 162
Л.И. Мирошниченко ...... 162
UPDATING 'CLASSICAL-PHYSICS': EXPERIMENTAL PROOF OF BOTH NON-EXISTENCE OF EMPTY SPACE PHOTONS MOVING THROUGH IT ...... 163
K. Mocnik ...... 163
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NEW EVIDENCE OF SOLAR INFLUENCE ON CLIMATE OF NORTH ATLANTIC AND NORTHERN FENNOSCANDIA ...... 163
Ogurtsov M.G.1,2, 2 Jungner H.3 ...... 163
TWO TYPES OF THE MAGNETOSPHERE RESPONSE TO THE INTERACTION WITH INTERPLANETARY SHOCKS IN THE GEOMAGNETIC PULSATIONS PSC ...... 164
Parkhomov V.A.1, Yahnin A.G.2, Borodkova N.L.3, Tsegmed B.4, Tero Raita5, Khomutov S.Y.6, Pashinin S.Y.7, Chilikin V.E.1, Mochalov A.A.2 ...... 164
LOCALIZATION OF IONOSPHERE SOURCES OF HIGH-LATITUDE GEOMAGNETIC PULSATIONS IN 2D FIELD DISTRIBUTIONS ...... 165
Petlenko A.V.1 ...... 165
PITCH-ANGLE DIFFUSION OF ENERGETIC PROTONS UPON THEIR INTERACTION WITH EMIC WAVES: COMPARISON OF THEMIS DATA ON WAVE SPECTRA AND ENERGETIC PARTICLES ...... 165
Popova T.A.1, Lyubchich A.A.1, Demekhov A.G. 1,2, Yahnin A.G.1 ...... 165
1 - Polar Geophysical Institute, Apatity, Russia ...... 165
2 - nstitutte of Applied Physics, Nizhny Novgorod, Russia ...... 165
THE LATITUDE AND LONGITUDE DISTRIBUTIONS OF COSMIC RAY CUTOFF VARIATIONS DURING THE MAIN PHASE OF THE MAGNETIC STORM IN NOVEMBER 2003 ...... 166
Ptitsyna N.G., Demina I.M., Danilova O.A., Tyasto M.I...... 166
THE CONTRIBUTION OF THE EARTH'S MAIN MAGNETIC FIELD VARIATIONS TO AURORAL ACTIVITY IN 1600-1909 ...... 166
Ptitsyna N.G., Demina I.M., Tyasto M.I...... 166
DIURNAL VARIATIONS OF THE BOTTOM EDGE OF THE IONOSPHERE DURING THE PROTON PRECIPITATIONS ON AND AFTER 29 SEPTEMBER, 1989 ...... 167
G. F. Remenets 1, M. I. Suhovey1 , V. A. Shishaev 2 ...... 167
BALLOONING INSTABILITY OF COUPLED MHD MODES IN 2D MODEL OF THE MAGNETOSPHERE ...... 168
Rubtsov A.V.1, Mager P.N.1, Klimushkin D.Yu.1 ...... 168
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PC5 COMPRESSIONAL EVENT OBSERVED WITH THEMIS: SPATIO-TEMPORAL STRUCTURE, WAVE-PARTICLE INTERACTIONS ...... 169
Rubtsov A.V.1, Agapitov O.V.2, Mager P.N.1, Klimushkin D.Yu.1, Mager O.V.1...... 169
ALFVÉN WAVES AS A DRIVER FOR MAGNETOSPHERIC DYNAMICS ...... 169
V. Semenov1, M. Kubyshkina1, I. Kubyshkin1, N. Erkaev2,3, E. Gordeev1, M. Shukhtina1, V. Sergeev1 ...... 169
DEPENDENCE OF ENERGETIC PROTON PRECIPITATION EQUATORWARD OF THE ISOTROPY BOUNDARY ON GEOMAGNETIC ACTIVITY ...... 170
N. V. Semenova1, T. A. Yahnina1, A. G. Yahnin1, and A. G. Demekhov1, 2 ...... 170
ADVANCES IN MAGNETOTAIL MONITORING DURING SUBSTORMS ...... 170
Sergeev, V.A. 1, N.A. Tsyganenko1 , E.I. Gordeev1, V.G. Merkin2, M.I. Sitnov2, V. Angelopoulos3, A.V. Runov3 ... 170
IONOSPHERE CHARACTERISTICS DURING SIMILAR GEOMAGNETIC EVENTS ...... 138
Blagoveshchensky D.V.1, Sergeeva M.A.2, Shmelev Yu.A.1 ...... 138
INNER MAGNETOSPHERE RECONFIGURATION DURING THE SUBSTORM GROWTH PHASE ...... 171
M. A. Shukhtina 1, E. I. Gordeev 1, V. A. Sergeev 1 ...... 171
RING CURRENT PROTON DYNAMICS DRIVEN BY WAVE-PARTICLE INTERACTIONS DURING A NONSTORM PERIOD ...... 172
Smolin S. V...... 172
THE SIMPLE ANALYTICAL DESCRIPTION FOR RELATIVISTIC (>2 MEV) ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT ...... 172
Smolin S. V...... 172
GEOMAGNETIC DISTURBANCES WITH SUDDEN AND GRADUAL COMMENCEMENTS IN 1869-1954 ACCORDING TO OBSERVATORY DATA AND CATALOGS OF STORMS ...... 173
Sergey Sokolov1, Vadim Soldatov1, Vladimir Koshelevsky1 ...... 173
SPATIAL-TEMPORAL CHARACTERISTICS AND PHYSICAL NATURE OF THERMAL ANOMALY DIAGNOSED BY THE EISCAT RADAR WITHIN THE DUSTED NIGHTSIDE AURORAL DYNAMO LAYER ...... 174
E.E. Timofeev,1 S.L. Shalimov,2,3 M.K. Vallinkoski,4 J.Kangas4 ...... 174
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CRITERIA FOR VULNERABILITY OF POWER TRANSFORMERS ELECTRIC POWER SYSTEMS WITH PERTURBATION OF COSMIC WEATHER ...... 175
Vahnina V.V., Kozub A.A. Dubinin M.V...... 175
MANIFESTATION OF 60-YEAR CLIMATIC CYCLE IN CORRELATION LINKS BETWEEN SOLAR ACTIVITY AND THE LOWER ATMOSPHERE CIRCULATION ...... 176
Veretenenko S.V., Ogurtsov M.G...... 176
LONG-TERM NORTH-SOUTH ASYMMETRY OF THE SOLAR MAGNETIC FIELD ...... 176
Vokhmyanin M., Zolotova N., and D. Ponyavin ...... 176
RECONSTRUCTION OF PARAMETERS OF THE SOLAR ACTIVITY IN XVII CENTURY .. 177
N. Zolotova1, M. Vokhmyanin1 ...... 177
VERIFICATION OF THE OMNI DATABASE USING PC INDEX...... 177
Vokhmyanin M.V., Stepanov N. A., Sergeev V. A ...... 177
RELATIVISTIC ELECTRON PRECIPITATION AND GEOMAGNETIC ACTIVITY ...... 178
A. G. Yahnin, T. A. Yahnina, and N. V. Semenova ...... 178
SIMULTANEOUS OBSERVATIONS OF EMIC AND VLF WAVES DURING MULTIPLE MAGNETOSPHERE COMPRESSIONS ...... 179
A.G. Yahnin1, J. Manninen2, T. Raita2, T.A. Yahnina1, E.E. Titova1, A.G. Demekhov1,3 ...... 179
ACCELERATION OF COLD ION COMPONENT AT THE SEPARATRICES DURING COLLISIONLESS MAGNETIC RECONNECTION...... 179
I. Zaitsev1, A. Divin1, V. Semenov1 ...... 179
TRIGGER REGIME OF THE MAGNETOSPHERE DYNAMICS IN THE SOLAR ACTIVITY CYCLE ...... 180
O.D. Zotov1, B.I. Klain2, N.A. Kurazhkovskaya3 ...... 180
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SECTION EG. EXPLORATION AND ENVIRONMENTAL GEOPHYSICS
Conveners - Dr. N.Y.Bobrov, Dr. A.K.Saraev
Exploration geophysics Engineering geophysics Environmental geophysics Integration of geophysical methods
STRUCTURE OF THE NORTHERN PART OF SOUTH-ONEGA SYNCLINE BASING ON AMT, GRAVITY AND MAGNETOMETRY DATA
K.Antashchuk1, K.Stepanov2, A.Saraev1.
1 – Saint Petersburg State University, Institute of Earth sciences
2 – FSBI “VSEGEI”
South-Onega syncline is located in southern part of Palaeoproterozoic Onega structure; it mainly consists of Low Proterizoic terrigenous rocks which include dolerite Ropruchey sill. These rocks cover the Archean basement. Geophysical investigations have been carried out along the sub-latitude line of 58 km length in order to clarify the geological structure of the syncline. The distance between AMT stations was 300-500 m; between magnetometry and gravity points – 50 m and 100 m correspondingly. AMT soundings were done using remote reference technique in the frequency band 0.1-1000 Hz. An area of 5 km length has been detected where the anomalies of TM impedance phases are observed. They exceed the 0-90 о quadrant at frequencies lower than 10 Hz. The mathematical modeling using two types of synthetic models has been realized in order to explain this phenomenon. First model included various blocks with electrical resistivity anisotropy; the modeling procedure was occurring in the framework of 2D media. It has been shown that such anisotropy model could not cause the observed anomalous impedance phase. The second type of models, based on a-priory geological data of the Onega area, included two regional and one local conductive bodies. The results of 3D modeling have shown that this type of models can cause the anomalous impedance phases. Then, the model which matches best the obtained AMT response has been created. The modeling results were used for further AMT data inversion. The geoelectric section obtained according to 2D inversion of AMT data was used for set of polygons configuration and further gravity data modeling. Density values for each polygon were choosing according to known rocks physical properties. Basing on modeling results of magnetic survey both high- magnetized rocks in the western part of investigation area and dolerites of Ropruchey sill in its central part have been allocated. Obtained geophysical data allowed us to construct the geological and geophysical models of investigated area up to 10 km depth. They also helped us to clarify the structure of South-Onega syncline. The thickness of protoplatform sedimentary cover is about 3 km. Graphitized zoneshave been detected in the terrigenous deposits. Several blocks with different density values have been divided in the basement structure.
25
BASIC 3-D GEOELECTRIC MODEL OF THE LITHOSPHERE OF BELARUS
Astapenko V.N., Dubanevich M.A.
Research and Production Centre for Geology, Akademika Kuprevicha st. 7, 220141, Minsk, Belarus
Magnetotelluric sounding were fulfilled at 372 locations within the territory of Belarus and one- dimensional inversion of effective curves of apparent resistivity was fulfilled. Effective curves are invariants relatively to registration axis and moreover they reflect a complex pattern of the electromagnetic field distribution within 3-D geologic medium. Three-dimensional geoelectric model of the lithosphere within Belarus is represented by diagrams of the electric conductivity distribution at depths of 5, 10, 15, 20, 30, 50, 70, 90, 120, 150, and 200 km. The produced model shows a sufficient areal differentiation. The resistivity of lithospheric rocks in the western part of Belarus belonging to the Fennoscandian block of the Earth’s crust is 1.5-2 orders higher than in its eastern part within the Sarmatian block. Similar differentiation is related to processes of the formation of depressions at the consolidated basement due to the tectonic activation happened during Paleozoic time. Four high-resistivity blocks are distinguished within the Belarus-Baltic Granulate Belt separated by zones with lower resistivity. Through-the-crust conducting zones were distinguished within the Pripyat Trough and Orsha Depression caused by regional faults: Stokhod-Mogilev, Perga-Surozh and Chashniki (in the northern part of Belarus) ones. In the eastern part of Belarus at all structural stages a meridional zone of increased conductivity was observed, which probably is related to the Trans-European Lineament Zone. At the North of Belarus the Polotsk-Kurzemian conducting zone was formed at the middle and lower crust levels.
TRANSIENT ELECTROMAGNETIC SOUNDINGS OF MAGNETICALLY VISCOUS ROCKS IN THE ZHAMANSHIN IMPACT CRATER
Bobrov N.Yu.
Saint-Petersburg State University
Magnetic viscosity most often caused by superparamagnetism (SPM) may significantly influence the results of transient electromagnetic soundings, especially in the case of high resistivity of the rocks. This effect manifests itself in slowly decaying transient response, so called “long tails” of sounding curves. This effect is described, for example, for Siberian platform flood basalts (Stognii et al, 2010). SPM effect occurs in rocks containing ultrafine grains of ferrimagnetic minerals. In well conducting rocks the signal caused by the induction transient process prevails over that associated with magnetic viscosity. If the latter is a subject of interest, one should reduce the size of sounding array (loop size). It is also established (Kozhevnikov, Antonov, 2008) that the maximal manifestation of SPM effect can be observed with a coincident-loop system. Zhamanshin astrobleme is an impact structure (age about 900 ka) situated in the Irgiz district of Kazakhstan, 300 kilometers north of the Aral Sea. In the spring of 2018 the field works have been carried out inside Zhamanshin crater aimed at studying the magnetic properties of impact rocks. Magnetic viscosity was one of the points of interest because previous studies found ferrimagnetic nanoparticles in some local impact melts (Starunov et al., 2016). In the course of field works a set of TEM soundings was performed at different points in the crater. TEM-FAST instrument was used with coincident square loops of different size, from 6 to 50 meters.
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It was established that allogeneic breccia dominating in the upper part of the section and terrigenous sediments overlapping breccia are very conductive (resistivity – first Ohm·m), in agreement with previous results of VES soundings (Dabizha et al, 1980). Nevertheless, an influence of magnetic viscosity was detected at some points with the use of small (6 and 12 meters) loops. Maximal SPM effect was observed in the eastern border of the crater where suevites are outcropping at the surface. Curves of apparent resistivity obtained at this point with the loops of different size diverge at the late times, whereas voltage curves approach the asymptote 1/t demonstrating the influence of magnetic viscosity. Static magnetic susceptibility estimated for the near-surface layer is of order 10-4 SI. The magnetic mineral responsible for SPM effect is not established yet, though magnetite seems the most probable candidate. Substantial magnetic viscosity of suevites was then confirmed by laboratory measurements of impulse magnetization response. Measurements were carried out with the help of a pulse induction system (two multi-turn coaxial coils) and a TEM-FAST instrument. In the time range 30-3000 mks impulse responses 퐸(푡) satisfy the power law = 푎 ∙ 푡−푏 with b value slightly different from unity, possibly indicating a 퐼 deviation of true relaxation time distribution from Frölich function (Kamnev et al., 2015). The work was supported by the RFBR grant 18-05-00626. References: Dabizha, A.I., Florensky, P.V., Alyunina O.I., and Alyunin A.V. Geophysical Investigations of Zhamanshin Crater, USSR. In Lunar and Planetary Science Conference, vol. 11, pp. 192-194. 1980. Kamnev, Y., N.O. Kozhevnikov, A.Kazansky, and S.M. Stefanenko, 2015, Impulse response of viscous remanent magnetization: Laboratory measurements by a pulse induction system. Russian Geology and Geophysics, 56, 1642–1651. Kozhevnikov, N.O., Antonov, E.Yu., 2008. The magnetic relaxation effect on TEM responses of a uniform earth. Russian Geology and Geophysics, 49, 197–210. Starunov, V.A., Kosterov, A.A., Sergienko, E.S., Kharitonskii, P.V. Magnetic properties of impact melts from Zhamanshin astrobleme. Proceedings of the 11th Intl School and Conference “Problems of Geocosmos”. Oct 03-07. 2016. St.Petersburg, Russia Stognii, V.V., Kozhevnikov, N.O., Antonov, E.Yu., 2010. TEM surveys for magnetic viscosity of rocks in situ. Russian Geology and Geophysics, 51, 1219–1226.
RECENT RESEARCH OF GEOPHYSICAL PARAMETERS OF THE LITHOSPHERE PLATFORM REGIONS
Burakhovych T.K, Kushnir A.N., Tsvetkova T.A.
Institute of Geophysics by S.I.Subbotin name, National Academy of Science of Ukraine, Kiev
In the course of geophysical investigations of the last decades a widespread presence of seismic and geoelectric inhomogeneities in the consolidated crust of continents was established. The main role in formations of these inhomogeneities is played by fluids and deep fluid systems. According data seismic tomography and Depth Seismic Sounding the fluid flows correspond to subvertical column velocity with alternating of high and low velocities. The last associated with the processes of stretching and compression density differentiation medium for passing fluid flow. These processes form the structures that are fixed as electroconductive layers. In the ancient platforms the areas of concentration of epicenters of seismic events are often lined up along zones of anomalies of electric conductivity. One can suggest that their close spatial correlation is due to the common nature of their formation. At the same time the absence of such correlation in other parts of 27 the ancient platforms tells us that nature of this correlation is not fully understood and requires further studies. As a result we obtained, that some of these anomalies are extended on thousands kilometers along regional and interregional high conductivity structures and can be the result of geodynamic processes. The similar correlation is observed at both American continents, Australia and within the European continent. In view of the fact that intra-plate earthquakes tend to zones of loosening of rock matter and the presence of such zones is usually related to fluids and their effect on the physical properties of rock matter it is possible to suggest that formation of a conducting layer and a wave-conductor in the Earth crust is defined by the metamorphic processes of dehydration and hydration - release of water and carbon acid. Migration of small amounts of fluids from upper mantle into consolidated crust also takes part in formation of such inhomogeneities.
RESEARCHING OF PHYSICO-CHEMICAL PROPERTIES OF RESEVOIR FLUIDS BY NMR-RELAXOMETRY METHOD
E.S.Chernova1, M.Y.Shumskayte2
1 - Novosibirsk State University, Novosibirsk
2 - Trofimuk Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk
Nowadays the methods based on the phenomenon of nuclear magnetic resonance (NMR) are becoming increasingly relevant in the petroleum industry. This method is used to evaluate the porosity and permeability properties of reservoir rocks and to study the physicochemical properties of fluids which saturate them. The work is aimed at analyzing capabilities of the NMR-relaxometry method for evaluating the viscosity and determining the group composition of oil containing fluids. Laboratory investigations were performed on the NMR-relaxometer "MST-05" with frequency of 2.2 MHz and magnetic field 0.05 T. A series of experiments was conducted on samples of liquid hydrocarbons from collector layers of some deposits in Western Siberia, their physicochemical properties were evaluated and also the obtained data were compared with the data of liquid chromatography. The NMR-method is based on recording the attenuation/losses of macroscopic magnetization, which arises from the precession of magnetic moments of hydrogen nuclei in an electromagnetic field. The main result of the measurements is a relaxation curve, whose mathematical processing gives a distribution of transverse relaxation T2 over time. The possibility of determining the group composition is due to the fact that different groups of chemical compounds (asphaltenes, tars, aromatics and saturated hydrocarbons) have different molecular mobility and, therefore, are characterized by different relaxation times T2: the greater the mobility of molecules, the longer the time T2, which characterized the fluid. As a result of comparison of the obtained data with the results of geochemical methods, it is possible to distinguish intervals of times T2, which are typical of various types of organic compounds, for example, light oil have relaxation times T2 greater than 200 ms. Laboratory NMR-researching of hydrocarbons are extremely important for determining their relaxation characteristics and subsequent typification, which is necessary to improve the techniques of interpreting the data of nuclear magnetic resonance logging.
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Further research will be directed to studying the physical and chemical properties of water-oil emulsions by NMR-relaxometry and dielectric spectroscopy methods and their complex interpretation. These methods are mutually complementary and are promising for petrophysical and geochemical research. The work was carried out with the financial support of the project RFBR 18-35-00112.
NEW MAGNETOTELLURIC STUDY OF THE DEEP STRUCTURE OF THE SOUTH-WESTERN CRIMEA
Desyatov D.O.1, Pushkarev P.Yu.1, Rokityansky I.I.2, Stafeev A.N.1, Yakovlev A.G.1,3
1 – Lomonosov Moscow State University, Moscow, Russia
2 – Subbotin Institute of Geophysics, Kiev, Ukraine
3 – North-West Ltd., Moscow, Russia
We present the results of magnetotelluric soundings, performed in the Mountainous Crimea along the profile Yalta-Novosyolovka. We consider methods of observation and processing of magnetotelluric data, obtained in abundant industrial noise area. Results of data analysis and two-dimensional inversion are described. In particular, electric conductivity anomaly, associated with the Predgorny (Piedmont) fault, was revealed. Geological interpretation of the resistivity cross-section until 5 km depth is provided.
THE FEATURES OF DEAD BAND AMT SIGNAL IN CHUKOTKA REGION
E.Ermolin1, O.Ingerov2, A.A.Yankilevich3, N.N.Pokrovskaya3, T.V.Davytkina3, V.Melnikov1 1 - GM-Service LTD
2 - Phoenix Geophysics LTD
3 - Saint-Petersburg Mining University
We analyze the amplitude spectra of the audiomagnetotelluric (AMT) natural-source signal. Special attention is given to the signal in the frequency range from 1 kHz to 5 kHz known as "dead band". We study the measurements of the base sites that were used during summer fieldwork in 2013, 2014 and 2017 in Chukotka Region (Russian Far East). The area is located above the Arctic Circle. As it has been described by previous researchers, the stable signal in the dead band can be acquired only at nighttime. We would like to point out that in the daytime the local maximum at 2.4 kHz frequency is observed within the dead band in Chukotka. The 2.2 kHz and 2.6 kHz frequencies can be reconstructed by using more than 3 hours of daytime data acquisition. These frequencies can be used as the ranging marks. These ranging marks sometimes allow to reconstruct the AMT curve by using the relationship between the amplitude and phase. It is possible that the continuous registration of time series at high frequencies and improving the ways of magnetic sensor installation will allow decreasing measurement length in the daytime and increasing data quality in the dead band. For equipment, it is currently important to perform operative amplitude spectra visualization immediately after performing measurements on the site.
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THE WAY OF THE HOST MEDIUM INFLUENCE CORRECTION IN THE EXPRESS-INTERPRETATION OF 2D MAGNETOVARIATIONAL ANOMALIES
E.Ermolin1, O.Ingerov2
1 «GM-Service» LTD
2 «Phoenix Geophysics» LTD
Earlier, the authors found out that by using the singular points on the cross-section of magnetovariational (MVP) data, it is possible to quickly determine the parameters of the 2D anomalous object (Ingerov and Ermolin 2010). The depth of the geometric center of the object (H) is defined as H = α• D + с (1). The relative conductivity of the cross section (G) is defined as G = γ• Textr (2). In these two linear relations, D is the distance between the singular points on the tipper magnitude pseudo-sections. Textr is the value of the period of singular points. It is known that the host medium influences the morphology of the MVP anomalies. In this paper, we propose a method for taking the influence of the host medium into account. The task is solved by determining the coefficients α, c and γ. The determination of the values of the coefficients is carried out in two stages. At the first stage, based on the results of the 1D inversion of the TM mode of magnetotelluric data, a horizontally layered host medium is determined. The second stage involves 2D modeling of the magnetovariational response functions. To determine the coefficients α and c, the calculation is performed for 2 models with two different depths (H). G remains constant. To determine the coefficient γ, the calculation is carried out for two models with different G (the depth H remains constant). Since dependencies (1) and (2) are linear, four calculations are sufficient to determine the coefficients.
DISTORTION OF LOCAL MAGNETOVARIATIONAL ANOMALIES BY EFFECT OF REGIONAL STRUCTURES
E.Ermolin1, O.Ingerov2
1 - GM-Service LTD
2 - Phoenix Geophysics LTD
We consider the influence of the host medium on the morphology of the magnetovariational (MVP) anomaly of a local object with a relative conductivity of the section 10,000 Sm•m and 500 m depth. Conclusions are based on mathematical modeling. As result of modeling results the following conclusions are valid: 1. The host medium affects the morphology of the magnetovariational anomaly. The morphology of the anomaly is primarily related to the parameters of the sedimentary cover. 2. If the local and regional anomaly can be visually separated, the presence of large remote regional conductors in the studied area has a very weak effect on the shape of the anomaly from the local 2D object. 3. The local magnetovariational anomaly, distorted by regional anomalies, can be isolated by simple subtracting the regional constituent of the components of the Wiese matrix from the original field. The
30 local component determination is most correct when the anomalous object is removed from the regional conductor at a distance greater than the depth up to upper edge of the anomalous object. 4. If the regional component is correctly taken into account, the methods of express interpretation of magnetovariational data and inversion can be applied to the isolated anomalies. At the same time, it is necessary to determine the parameters of the horizontally layered host medium and take the influence of the host medium into account. 5. The local body appears on the AMT and MVP responses in different frequency bands.
ANALYSIS OF THE EFFECT OF ENVIRONMENTAL FACTORS ON THE DISEASE INCIDENCE OF PETROZAVODSK RESIDENTS, BASED ON EMERGENCY CALL DATA
Gerasimova А.А., Belashev B.Z., Krutskikh N.V.
Institute of Geology, Federal Research Centre, Karelian Research Centre, RAS, Petrozavodsk Russia
Environmental pollution, climatic characteristics and magnetic field perturbances are the factors that affect the disease incidence of the population. Therefore, the aim of the present study is to analyze the profiles of diseases and to assess the effect of geomagnetic field variations and pollution level on the aggravation of diseases with examples from Petrozavodsk. The city is located in an auroral latitude zone with frequent magnetic field variations, and its individual areas differ in geological conditions and ecological situation. The study was conducted using the data obtained by Petrozavodsk Geophysical Observatory at Petrozavodsk State University, the geomagnetic activity index Кр , and the BSMP impersonified emergency call database for Petrozavodsk, which is used to assess statistical information on disease incidence. Pollution is evaluated from the data obtained during ecologo-geochemical soil studies in 2011. Calculations of the distribution of emergency calls and environmental factors were made using the MATLAB computer mathematics system. The profiles of various groups of diseases were obtained and maps, showing their distribution in various city zones, were compiled. Subdivision of patients into various groups with regard for their sex and age shows the demographic characteristics of the population. Analysis of the time dependence of emergency calls has shown that daily call trends for individual diagnoses indicate that they are affected by seasonal factors. The time course of the number of calls for some of the diagnoses were found to contain the components similar to the rotation periods of the Sun and the Moon. The absence of the correlation of the daily emergency calls with the diagnosis “myocardial infarction” and geomagnetic activity index Кр, values has initiated the studies which showed that the minimum number of calls is consistent with the most common index values and deviations from it to one or another side increase the number of calls. The maximum number of emergency calls is registered on the first day after a magnetic storm. Integrated analysis of the soil cover pollution level and the number of calls has revealed the dependence of the growth of the various forms of diseases on environmental conditions. The closest correlations were shown for the diseases of the cardio-vascular system and areas with high soil pollution levels. The relationship of pollution and psychical diseases is less obvious.
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THE EXPERIENCE OF LOW-ALTITUDE MAGNETIC SURVEY USING UNMANNED COMPLEX GEOSCAN 401
Goglev D.A., D.J. Capstan, Tsirel V.S.
GEOSCAN
For many years, mankind has been trying to make a breakthrough in the development of technology. Such terms as robot, drone, artificial intelligence are deeply entrenched in the consciousness of modern man. Do we know for what we need all these innovations for? This article presents the experience of using unmanned aerial vehicles in magnetic exploration. Magnetic exploration is one of the oldest geophysical methods, without which almost no search for minerals can do. For more than a dozen years, magnetic exploration is mainly carried out in two ways: from the aircraft and in the pedestrian version. Both variants of magnetic exploration are quite expensive, and pedestrian shooting is often impossible because of the difficult landscape conditions. GEOSCAN group of companies, having studied this problem, decided to create an alternative version of the magnetic survey. Being one of the leading developers of software and unmanned aerial systems and understanding all the advantages of the UAV application, we have developed a quantum magnetometer on rubidium vapors and installed On an unmanned aerial vehicle of the GEOSCAN 401 series. With a flight range of 20 km with a magnetometer and an average speed of 36 km/h, the GEOSCAN Geophysics complex greatly facilitates and accelerates the production of accurate magnetic data. The first test flights confirmed the high efficiency of both the created magnetometer and the system as a whole. Thanks to the achievements of the company in the field of construction of accurate maps of the area, it became possible to perform magnetic survey at extremely low altitude with a detailed envelope of the terrain. The work, which was first carried out in Yakutia for the needs of LLC “Neryungriheofizika” at the iron ore Deposit, and then in southern Kazakhstan on the order of LLP “SPC”Geoken”, aimed at finding gold and stratiform polymetallic mineralization, showed high convergence of materials with the previously carried out on the same ground and air magnetic exploration sites. The average quadratic error in the works in Kazakhstan exceeded all expectations and was less than 0.5 NT. In July 2018, the specialists of GEOSCAN carried out commercial work in the TRANS-Baikal region, near the village of Gazimur Plant. Over 10 days, more than 800 km of profiles were investigated to search for gold epithermal mineralization. Thanks in advance created the map of the heights failed to carry out work under the radar without a single contingency. The equipment has confirmed its high potential and ease of use. The main advantages of magnetic surveys using unmanned technologies GEOSCAN over the classical methods of obtaining magnetic data is its high performance (up to 160 km per day), detail, much less noise, economic efficiency, possibility of obtaining reliable data from areas inaccessible to survey by other means. Recently, an increasing number of companies are interested in new technologies – including geophysical surveys using UAVs. According to forecasts, in the near foreseeable future, low-altitude magnetic survey from an unmanned aerial vehicle will significantly displace ground photography and even replace it.
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ON NECESSITY OF GEOLOGICAL ENVIRONMENT MODEL COMPLICATION FOR MONITORING ITS STATE AND FORECAST ITS STABILITY
Hachay O.1, Khachay O.2, Khachay A.2
1 – Institute of Geophysics UB RAS
2 – Ural Federal University
The most important result of geomechanical and geodynamic studies of the past century was the discovery of a close relationship between global geodynamic and local geomechanical processes caused by mining operations, especially in tectonically active zones. No less important result of the research was the conclusion about the fundamental role of the block-hierarchical structure of rocks and massifs for explaining the existence of a wide range of nonlinear geomechanical effects and the emergence of complex self-organizing geosystems. Hierarchical structure is typical for many systems, especially for the Earth's lithosphere, where more than 30 hierarchical levels from tectonic plates with a length of thousands of kilometers to individual mineral grains of millimeter size were identified by geophysical studies. Thus, the earth's crust is not a continuous medium, but a discrete block system and, like any synergetic discrete ensemble, has hierarchical and self-similarity properties. The processes of development of oil and gas fields are associated with the motion of multiphase multicomponent media that are characterized by noneqiulibrium and non-linear rheological properties. The real behavior of reservoir systems is determined by the complexity of the rheology of moving fluids and the morphological structure of the porous medium, as well as by the variety of processes of interaction between the liquid and the porous medium. Accounting for these factors is necessary for a meaningful description of filtration processes due to the nonlinearity, non-equilibrium and heterogeneity inherent in real systems. In this case, new synergetic effects are revealed (loss of stability with the appearance of oscillations, the formation of ordered structures). This allows us to propose new methods for monitoring and managing complex natural systems that are tuned to account for these phenomena. Thus, the reservoir system from which to extract oil is also a complex dynamic hierarchical system. When constructing a mathematical model of a real object, it is necessary to use, as a priori information, active and passive monitoring data obtained during the current operation of the facility. Modeling algorithms were constructed in the electromagnetic case for 3-D heterogeneities, in the seismic case for 2- D heterogeneities for an arbitrary type of excitation source of an N-layer medium with a hierarchical elastic inclusion located in the J-th layer. A new 2D modeling algorithm for sound diffraction on elastic and porous saturated saturation of a hierarchical structure located in the J-layer of an N-layer elastic medium was developed in the paper. Modeling algorithms were constructed in the acoustic case for 2-D heterogeneity for an arbitrary type of excitation source of an N-layer medium with a separate hierarchical anomalous density, strained and plastic inclusion located in the J-th layer. In the further paper, using the method described early, an algorithm for modeling the acoustic field (longitudinal acoustic wave) has been developed in the form of an iterative process for solving a direct problem for the case of three hierarchical inclusions of l, m, s-ranks using 2D integral and integro-differential equations. The degree of hierarchy of inclusions is determined by the values of their ranks, which can be different. Hierarchical inclusions are located in different layers above each other: the upper abnormally plastic, the second fluid saturated and the third anomalously dense. When constructing a complex seismic gravity model without taking into account the anomalous influence of a stress-strain state inside a hierarchical inclusion, called the pillow of the deposit, an analysis of the anomalous acoustic effect using data on the propagation of a longitudinal wave shows that the influence of anomalous elastic parameters in the seismic model cannot be neglected, since they affect on the values of the unknown anomalous densities. If these values are used in constructing a density gravitational model without taking into account the effect of elastic parameters, these density values will not reflect the material composition of the analyzed medium. When constructing an anomalously strained geomechanical model without taking into account the anomalous influence of
33 density heterogeneities inside the hierarchical inclusion, which is the substrate for a two-phase deposit, the values of the unknown anomalous elastic parameters that cause the anomalous stress state in the pillow using data on propagation of the transverse wave will be determined incorrectly. These values of the elastic parameters will not reflect the real stress state of the analyzed medium located above the fluid containing deposit, which in turn is represented by a hierarchical multi-neighborhood environment. For the first time, the proposed iterative algorithm for modeling a hierarchically complex two-phase medium can be used to control the production of viscous oil in mine conditions and light oil in sub horizontal wells.
NATURAL ULF PERTURBATIONS OF THE ELECTRIC FIELD IN COASTAL ZONES
Ismagilov V.S., Kopytenko Yu.A.
SPbF IZMIRAN, St. Petersburg,
In 2016-2017 SPbF IZMIRAN conducted experiments on the study of ULF electromagnetic disturbances on the coast of the Barents and Okhotsk sea. Data logging was performed by geophysical stations GI- MTS-1 located on a coast near the water's edge and in remote points moved away from the coast at hundred meters. It was found that the resonance ULF variations of electric field arises in a narrow (~50-100 m) Barents sea coastal zone. The variations have a good correlation with tides (~4.5 m height above zero sea level). Frequencies of the variations change from 0.1 to 0.2 Hz during a tidal period. The effect was not observed at other station situated at the coastal line and at remote station situated at ~700 m from the coast. At a narrow zone of Okhotsk sea an effect of correlation of electric field variations during the sea tide periods (~2.4 m height above zero sea level). In contrast to Barents sea experiment we observed intensity amplification of electric field disturbances during the tides periods. These intensifications were observed in a broad frequency range (F = 0.001 – 1 Hz). It was found also an intensification of the wideband electric field disturbances during a periods when a wind velocity growth. The effect was observed only in the narrow coastal zone. At remote stations the effect was weaker in 3-5 times. We suppose that the observed phenomena are connected with the marine aerosol positive charges and the coastal glyph.
DEEP MAGNETOTELLURIC SOUNDING OF THE NORTHERN PART OF THE SCYTHIAN PLATE
Kushnir A.N.1, Bryashko N.V.2
1 – Institute of Geophysics by S.I.Subbotin name, National Academy of Science of Ukraine, Kiev
2 – Institute of Geology, Kiev Natsonal Taras Shevchenko University
[email protected], [email protected]
Modern experimental researches on the study of the natural low-frequency electromagnetic field of the Earth with the use of modern equipment, processing of their results based on universal program packages and interpretation (including on a qualitative level) can provide detection of electric conductivity 34 anomalies and the research of the deep structure of the Earth's crust and mantle. The deepest point of the MTS village Ridne (N 45.70; E 34.60) characterized by complex geological-tectonic structure and located in the northern part of the Scythian Plate, in the Sivas through between the Chongar and Melitopol- Novocaritsyn defective zones. The total longitudinal conductivity according to the literary sources at the point Ridne is 700 S, while the isohypses of the surface of the Upper Cretaceous reach 1700 m. The processing was performed according to the standard one-point evaluation method. As a result, the curves of the apparent electrical resistance in the meridional and latitudinal directions ρxy, ρyx, impedance Zxy, Zyx, and impedance phases φxy, φyx. The curve ρyx is characterized by a continuous rise in the level of apparent electrical resistance and only reflects the value of total longitudinal conductivity of sedimentary deposits, and only in the largest periods of 3000 - 5000s there is a decrease in the value ρa with the output of the curve on global data. This indicates a lack of significant regional galvanic distortions of the curve. The curve ρxy is characterized by an ascending branch of the sedimentary strata in the range of periods of 20 - 200 s and with the presence of a characteristic bend on 200 - 1000 s with a pronounced minimum in the range 700 - 2000 s. The curve ρxy after 1000 s is an order lower than the transverse and does not reach the level of global data. As a result of qualitative interpretation of the deep curves of the MTS, a layer of elevated conductivity with a total longitudinal conductivity about 3000 - 5000 S and a boundary of the upper edge at depths of 50 to 100 km was allocated. The total longitudinal conductivity of the sedimentary layer along the ascending branches ρa reaches over 400 S. The results obtained in the point Ridne are in good agreement with the results of research performed in previous studies.
MT/MV STUDIES OF THE KIROVOGRAD ANOMALY OF ELECTRIC CONDUCTIVITY IN THE SOUTHERN OF THE DENIPER-DONETSK BASIN SLOPE
Kushnir A.N., Burakhovych T.K, Ilyenko V.A.
Institute of Geophysics by S.I.Subbotin name, National Academy of Science of Ukraine, Kiev
According to the results of qualitative interpretation of the curves ρa for different periods and the values of the total longitudinal conductivity of the upper layer of sedimentary deposits (Ssed) the profile can be divided into three parts: the first (0-50 km) – starting point (4956.6°N, 03241.7°E) – values ρa for different directions the measure lines (ρху, ρух) coincide and is in the range of values from 10 to 100 Ohm·m in almost the entire frequency range; The second (50‒110 km) – the values of ρху and ρух differ for 1‒1,5 orders, ρху is on average equal to 1÷10 Ohm·m, while ρух is 10÷100 Ohm·m; The third (110‒ 190 km) – final point (4918.66°N, 03459.7°E) – the value of ρa from 1 to 50 Ohm·m throughout the frequency range increases with the increase of the period, the difference between ρху and ρух is observed at periods greater than 100 s and is equal to one order.
The value of Ѕsed increases gradually in the east direction from 450 (DDB slope) to more than 1000 S (axial part of DDB). However, the information on the integral electrical conductivity of the surface layer Ѕsedob, obtained on the ascending line of the observed curves ρa, does not support this information. In the first part of the profile Ѕsed and Ѕsedob almost coincide and equal to 450‒600 S, then in the interval from 50 to 110 km Ѕsedob the values correspond to 400‒500 S and almost twice low then Ѕsedob which equal 900 S, and in the interval of more than 110 km Ѕsedob are twice as high as Ѕsed and equal to almost 2000 S.
The comparison of the behavior of the data Ѕsedob and ρa indicates the existence of the deep electrical anomaly in the middle part of the profile and implies it in the eastern. The results of the qualitative interpretation of the curves of the МТ showed that the minimum depths of the upper edge of the conductor vary from 20-30 km in the southwest on the slope to the maximum values of 50 km in the axial zone of the DDB. 35
The profile crosses the south-eastern part of Glydyntsivska area, which is characterized by the presence of the core and mantle rock mix with a capacity of 2‒5 km that is the characteristic for oil and oil condensate fields. In addition, fracturing and deconsolidation in the basement and consolidated crust at depths of 20‒ 30 km, due to the large node of intersection of fault zones of different systems. Deep anomalies in electrical conductivity can be explained by the penetration of the fluids from the crust and the mantle, and they are an important source for all processes of oil and gas deposits formation.
DEEP ELECTRIC CONDUCTIVITY OF THE AVACHA-KORYAKSKIY GROUP OF VOLCANOES, KAMCHATKA
Yu. F. Moroz1,2, V.A. Loginov1
1Institute of Volcanology and Seismology FEB RAS, 683009, Petropavlovsk-Kamchatsky, Piip Blvd. 9
2Geological Institute SB RAS, 670047, Ulan-Ude, Sakhyanova 6a
e-mail: [email protected], [email protected]
Investigation of deep structure of the Avacha-Koryakskiy group of volcanoes in the vicinity of Petropavlovsk-Kamchatsky is a vital task. In previous years scientists conducted various magnetotelluric soundings and collected various data, but a large size and a narrow bandwidth of the equipment prevented from detailed research of the electrical conductivity beneath the Avacha-Koryakskiy group of volcanoes. In recent years, we have conducted 45 km magnetotelluric lateral sounding in increments of 0.5 to 2 km from SW to NE using MTU-5A equipment with an extended range of periods and analyzed geoelectrical setting. Test models allowed studying coast effect as well as terrain effect in MTS curve behaviour. A deep geoelectrical section was created using inversion of longitudinal MTS curves within the TM-mode. In order to improve the structure of electrical conductivity in the upper zones of the section, we used transverse curves within the range of periods free from coast effect. We created a 60-km-deep geoelectrical model. There is a well-marked sedimentary-igneous layer beneath the Avacha-Koryakskiy group of volcanoes with lower resistivity to 5-10 Ohm m at the depths from the first hundreds of metres to 2-5 km. Maximum thickness was revealed in Avacha graben, which is located west of Avacha and Koryakskiy volcanoes. There is a marked crustal layer with an increased conductivity in the south-western part of the profile between depths of 15-25 km connected with a subvertical conductive deep zone. The deep part of the model includes subvertical conductive zones with resistivity varying from the first ones to 10 Ohm m. An anomaly zone with the increased conductivity is adjacent to the upper part of Avacha graben and extends as deep as 30 km. The second anomaly zone with the increased conductivity with resistivity from the first ones to 10 Ohm m was revealed in depth range between 10 and 40 km. It is connected with a sedimentary-igneous cover through a narrow conductive channel. These deep anomalies are probably faults that include liquid fluids as hydrothermal solutions and magmatic melts. Partial rock melting in fault zones is likely due to solutions incoming from the crustal layer and creeping vadose waters, which substantially reduce the melting temperature of the lithospheric rocks.
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PECULIARITIES IN GEOELECTRICAL STRUCTURE OF KAMCHATKA EAST COAST
Moroz Yu.F.1,2, Samoylova O.M.1
1 – Institute of Volcanology and Seismology FEB RAS, Petropavlovsk-Kamchatsky,
2 – Geological Institute SB RAS, Ulan-Ude; Institute of Volcanology and Seismology FEB RAS, Petropavlovsk-Kamchatsky.
The rock conductivity is important characteristic of the Earth’s interior thermodynamic properties. Information about deep conductivity has been got in Kamchatka along two regional profiles using magnetotelluric sounding (MTS) method. The first profile “Severny” stretches out on 350 km along north-eastern Kamchatka coast from Ossora settlement to Tilichiki settlement. The second profile is situated on the territory of south-eastern coast from Nicolaevka settlement to Khodutka bay. Geoelectrical sections were obtained along the regional profiles to a depth of about 80 km. The identified anomalies of electrical conductivity were compared with the data obtained by other geophysical methods (specifically, the data on gravity and anomalous magnetic fields). The comparative analysis of the geoelectrical sections shows that electrical conductivity changes gradually in the northeastern region, while the structure of the southeastern region is represented by blocks differing in geoelectrical properties. The conducting horizon of the lithosphere lies at different depths in different parts of East Kamchatka. Nature of the conducting stratum is related to solutions of high mineralization. Heat flow at investigated areas changes from 70 to 80 mV/m2. Such a high temperature causes regional metamorphism processes at the depth of about 12 km which result in separation of the water. This water has a high dissolving power at high temperature and pressure. This results in the formation of high mineralization solutions, decreasing resistivity in the medium.
DEEP GEOPHYSICAL MODEL OF THE AREA BETWEEN SHANUCH COPPER-NICKEL DEPOSIT AND AGINSKOYE GOLD DEPOSIT IN KAMCHATKA
Moroz U.F., Ulybyshev I.S.
Institute of Volcanology and Seismology FEB RAS
Aginskoye gold and Shanuch copper-nickel deposits are located in different structural zones. The Shanuch deposit is located in the Middle Massif of metamorphic rocks. The Aginskoye deposit is dedicated to the area of joint of the massif with the volcanic zone. Study of a profile 55 kilometers length between the deposits was made by method of magnetotelluric sounding. The observation step is irregular - from 2 to 4 km. For a comprehensive analysis of geophysical data were used aeromagnetic and gravimetric surveys of past years. As a result of solving the inverse problem were revealed the main features of the deep structure of the earth's crust and upper mantle. In the geoelectric section of the earth's crust are distinguished two blocks with different electrical conductivities: the western and the eastern. The Western block is located in the Middle Massif of metamorphic rocks, which are brought to the surface here, and is characterized by increased electrical resistances. In magnetic and gravitational fields this region is characterized by weakly perturbed negative relative anomalies of magnetic field and gravity. The eastern block of the earth's crust 37 is distinguished by the increased electrical conductivity of the sedimentary-volcanogenic cover associated with the influence of a wide network of tectonic disturbances. The increase in the intensity and frequency of the anomalies of the magnetic field and gravity is also associated with deep faults. This block is confined to the area of articulation of the eastern edge of the massif with the volcanic zone. In the lower part of the section, a relatively conductive layer is separated at depths of 30-60 km, which is associated with the presence of mineralized solutions and igneous melts in it. Deep faults in the area of the Aginskoye deposit can penetrate through the earth's crust to the lithospheric conducting layer, and serve as channels through which the fluids rise to the upper horizons of the earth's crust. As a result of cooling and reducing the pressure from the fluids, accumulations of minerals forming deposits of non- ferrous and noble metals are formed. The Shanuch deposit, apparently, has a different nature. It is confined to ancient intrusives, brought to the surface as a result of tectonic activity. The work was carried out within the framework of the RFBR project No. 16-05-00059a, as well as on projects of the Far East Region No. 16-I-1-012e, No. 15-I-2-008.
THE INFLUENCE OF THE DAILY TEMPERATURE ON RESISTIVITY OF SULFIDE MINE TAILINGS
Osipova P.S., Olenchenko V.V., Bortnikova S.B., Yurkevich N.V.
Trofimuk Institute of Petroleum Geology and Geophysics SB RAS
Wastes from the enrichment of sulfide ores are stored in dumps or tailings. High concentrations of metals (Fe. Zn, Cu, Pb, Ag and Au) accumulated during storage, so such objects can considering as “technogenic deposit” [1]. Ores are susceptible to hypergene changes under the influence of outside temperature. Technology of secondary processing of mine tailings will depend on the degree of hypergene transformation. Daily variations of outside atmospheric parameters lead to a change in the natural electrical fields and resistivity (ρ) [2]. The temporal dynamics of geoelectrical fields are often observed on ore deposits [3]. The temporal changes of geolelectrical properties that occur during the hypergene transformations of technologene systems was the object of our study. The main purpose of this work is to determine the nature and causes of the variation in the resistivity of the waste material during the day. The study area is the tailings dump formed during the mining of the Beloklyuch deposit (Kemerovo region). Gold was extracted from the upper parts of the ore bodies by cyanidation in the 1930-s years of the last century. The structure, morphology, mineral composition of the ore bodies, the sequence of mineral formation have been studied and described by many researchers [4]. The Electrical resistivity tomography (ERT) is most often used among geophysical methods to study the mine tailings [5, 6]. Measurements were conducted by micro-electrotomography method on the surface of the tailing. The sequence of connecting the electrodes corresponded to a dipole-dipole array. The length of the profile is 9.1 m, the depth of the survey is up to 1.5 m. The measurements of rhe resistivity were carried out every hour during the period of 24 hours. We determined the temperature of the tailings by a probe at a depth of 0.1 m in the middle of the profile. The geoelectric section of the tailing has zones of reduced and elevated resistivity according to the ERT data. The anomalies of high resistivity correspond to the materials, which was changed as a result of hypergenesis. Regular dynamics of ρ during the day on the graphs of electrical profiling refers to the areas of increased resistivity. The daily temperature variation of the tailings and its ρ showed a strong inverse correlation (K=-0.97). As the temperature of the tailings decreases, the resistivity increases, and vice versa. We attribute this effect to the change in the conductivity of the pore solution. This dependence
38 is expressed by an exponential law, which is confirmed by other works [7, 8]. We conclude that the air temperature is the main physical factor of the resistivity dynamics in tailing subsurface section. Thus, the resistivity of the tailings depends on the outside temperature. Maximum changes are noted in the zones of intensively altered rocks because of hypergenesis. This feature can be used as a criterion for determining the degree of mine tailings transformation. References: 1. Yurkevich N. V, i dr. Ocenka sovremennogo sostojanija hvostohranilishha zolotorudnogo proizvodstva: cennye i toksichnye komponenty //Interjekspo Geo-Sibir'. – 2017. – T. 2. – №. 4. – S. 113- 117. 2. Balasanjan S. Ju. Dinamicheskaja geoelektrika. Novosibirsk: Nauka, 1990. – 232 s. 3. Avgulevich D. L. Issledovanie menjajishhihsja vo vremeni estestvennyh jelektricheskih polej Zemli s cel`ju vyjavlenija zakonomernostej ih formirovanija I sovershenstvovanija metoda estestvennogo jelektricheskogo polja: dis. Na soiskanie uchenoj stepeni kand. Geol.-min. nauk: dis. – Irkutsk: dis. Kand. Geol.-mineralog. Nauk, 2003. 4. Distanov Je. G. Kolchedanno-polimetallicheskie mestorozhdenija Sibiri. Novosibirsk, Nauka, 1977. 5. Bortnikova S. B. et al. Evidence of trace element emission during the combustion of sulfide-bearing metallurgical slags //Applied geochemistry. – 2017. – T. 78. – C. 105-115. 6. Martínez-Pagán P.et al. Electrical resistivity imaging revealed the spatial properties of mine tailing ponds in the Sierra Minera of Southeast Spain //Journal of Environmental & Engineering Geophysics. – 2009. – T. 14. – №.2. – C. 63-76. 7. Besson, A., Cousin, I., Dorigny, A., Dabas, M., King, D., 2008. The temperature correction for the electrical resistivity measurements in undisturbed soil samples: analysis of the existing conversion models and proposal of a new model. Soil Sci. 173 (10), 707–720. 8. Ma R. et al. Comparing temperature correction models for soil electrical conductivity measurements //Precision Agriculture. - 2011. – T. 12. – №. 1. – C. 55-66.
ABOUT MEASUREMENT OF VERTICAL COMPONENT OF ELECTRIC FIELD AT MAGNETOTELLURIC SOUNDING
Plotkin V.V., Mogilatov V.S.
Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk, 630090 Russia
At magnetotelluric sounding (MTS) variations of five components of the electromagnetic field are usually registered. At standard approach transfer functions are defined in an experiment namely ratios between horizontal components of electric and magnetic fields. Deviations from the Tikhonov–Cagniard basic model are defined by fifth registered component namely by vertical component of magnetic field. Because of the complex geoelectric structure of the medium and in the presence of the MTS curve distortions, there are difficulties at interpretation of data in practice. For increase in reliability of the received results by the inversion and for bigger informational content of MTS, it is offer to carry out the additional registration of vertical component of electric field in the medium. Comparison of calculated values with experimental data on this component at the solution of the inversion task is very desirable. To register variations of the vertical electric component, now the method of measurement of potential difference arising on the vertical line shipped in the sea is applied. On the land for this purpose it is necessary to drill new wells or use available ones, that is difficult. It is offered to apply the circular electric dipole (CED) for registration of the vertical electric component. Now CED is successfully apply as the emitter in methods of electromagnetic soundings. Its feature is use to excite only one TM-mode in 39 which electric field has vertical component in the layered medium. In practice, CED usually is implement by eight long radial lines. Considering the specified feature, CED can be used and as the MTS receiver for registration of variations of the field of TM-mode. Possibilities of its use at MTS are analyzed in this work. This work is supported by the Russian Science Foundation under grant 18-17-00095.
ABOUT THE ROLE OF THE HALL EFFECT AT MAGNETOTELLURIC SOUNDING
Plotkin V.V., Mogilatov V.S.
Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk, 630090 Russia
The containing rocks over deposits of oil and gas penetrated by a stream of hydrocarbon fluids represent the semiconductor medium in which manifestation of Hall’s effect is possible. Interest in this phenomenon has arisen by results of electromagnetic soundings with controlled sources in regions of areas of hydrocarbons. The similar phenomena are possible also owing to impact of Earth’s magnetic field on the currents caused in fluids at electromagnetic soundings of porous geological media. Here the role of viscosity and conductivity is big. Their coefficients can be defined during the experiments. So far, for the geological media the characteristic of microprocesses are known insufficiently, therefore it is better to address an experiment. For its planning, it is possible to consider influence of the Earth’s magnetic field, introducing Hall’s conductivity tensor. In the anisotropic medium, the field splits to the components differing in coefficients of attenuation and phase speed – normal modes. The difference of modes connected with its polarizations and the direction of rotation of a vector of the field, in one mode the field rotates clockwise, in the second against. For physical reasons clearly that due to Hall's effect the response of the medium can be unequal in cases of excitation of the medium by only one of normal waves. For detection of influence of the Hall’s effect in magnetotelluric sounding the method of the polarizing analysis based on a data processing algorithm with division of a time spectrum of the MT-field into spectra of normal modes with the right and left circular polarization is offered. This work was executed by financial support of the Russian Foundation for Basic Research, grant 17-05- 00083.
INFLUENCE OF MOSCOW MEGACITY ON NEAR-SURFACE ELECTRIC FIELD VARIATIONS
Riabova S.A., Spivak A.A.
Institute of Geospheres Dynamics of Russian Academy of Science
The construction and development of megacities can disrupt the natural regime of physical fields, which negatively affects the environment and biological objects. In this vein, variations of the electric field in the near-surface layer of the atmosphere in the Moscow region were considered. The capabilities of the Geophysical Monitoring Center of Moscow created in 2014 at the Institute of Dynamics of the Geospheres of the Russian Academy of Sciences allow to perform continuous registration of the electric field in the near-surface layer of the atmosphere and to isolate disturbances of anthropogenic nature from 40 sources located in the megacity. In order to establish the influence of a megacity on the electric field variation in the surface atmosphere, a comparative analysis of the data obtained at the Geophysical Monitoring Center of Moscow and Geophysical Observatory Mikhnevo of the Institute of Geosphere Dynamics, located 85 km south of Moscow outside the zone of megacity influence (coordinates 54.9595º N; 37.7664ºE) is carried out. Under similar weather conditions, the amplitude and diurnal variations of the electric field strength in Moscow and outside the zone of megacity influence are close. The passage of atmospheric fronts, atmospheric precipitation leads to a change in the magnitude of the electric field. Moreover, man-made sources in the form of fire have a significant effect on the magnitude of the electric field. In particular, a strong fire in the north-east of Moscow (2015.12.10) with an area of ignition of about 15 thousand m2 caused a significant local warming of the atmosphere, as a result of which powerful variations in the electric field strength.
FEYNMAN CORRECTIVE ELECTRICAL FIELD
B.G. Sapozhnikov
Institute of Environmental Geoscience of the Russian Academy of Sciences (St Petersburg Division)
Full DC electric field is treated as a vector sum of the «retarded» and the «corrective» fields of Feynman formula. It is demonstrated the ability to express «magnetic» field and «corrective» electrical fields, accordingly, through single and double rotors of vortex «retarded» field. Examples of DC devices (railgun, magnet) confirm the workability of electric field in contrast to magnetic. It is shown that the principle of short-range interaction of the electric field is valid in the Ehrenberg-Siday-Aharonov-Bohm experiment.
INFLUENCE OF DISPLACEMENT CURRENTS ON THE RESULTS OF FREQUENCY SOUNDINGS ON THE EXAMPLE OF THE RESULTS OF THE EXPERIMENT "KOVDOR 2015"
Shevtsov A.N.
Geological Institute KSC RAS, Apatity
This paper addresses the Kovdor-2015 Experiment involving frequency electromagnetic soundings of the Archaean basement of the Earth's crust in the southwestern part of the Kola Peninsula. Eleven soundings were carried out using two transmitting arrangements, 85 km apart. Each arrangement consisted of two mutually orthogonal grounded electric dipoles of 1.5 km long. The distances between the source and the receiver were 25 and 50 km. Interpretation of the results took into account the influence of displacement currents and static distortions. The effect of displacement currents is observed at high frequencies (above 800 Hz for distances of 50 km for apparent curves of the resistivity of the horizontal components of the magnetic and electric fields and above 1200 Hz for distances of 25 km). These curves differ from the apparent resistivity curves for the impedance components and increase with increasing frequency, while at the same time the apparent resistivity curves for the main impedance components continue to follow the dependence of the earth conductivity on the depth. This influence depends on the values of the resistivity and the distance from the source.
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Thus, the joint interpretation of the apparent resistance curves for the impedance components and field components within the framework of the quasi-stationary approximation in the upper part of the geoelectric cross-section does not make sense. At the same time, the effect of displacement currents on the apparent resistivity curves for field components depends not only on the resistivity (conductivity) of the rocks but also on their dielectric permittivity.
THE SOLUTION OF THE 2-DIMENSIONAL INVERSE MESD PROBLEM ON THE SELIVANOV-HIITOLA-SORTAVALA-SUISTAMO (NORTHERN LADOGA) Shevtsov A.N., Kolesnikov V.E. Geological Institute KSC RAS, Apatity [email protected] To date, a large volume of MT-AMT research in the Northern Ladoga area has been completed. All of them refer, mainly, to the problem of the deep structure of the Ladoga anomaly. But, the electrical conductivity of rocks that come out close to the surface of the day, has been little studied. The main reasons were complex terrain conditions and the extreme meandering of the coastline, and the poor development of the road network. To compensate for the gap formed by the combined team of the Geological Institute of the Kola Science Center of the Russian Academy of Sciences and the Institute of Geology of the Karelian Research Center of the Russian Academy of Sciences in 2015 and 2017, electric profiling with a direct current along the Hiytola-Syustamo profile was performed in conjunction with AMT-MTZ. In this paper, we consider the results of measurements using the method of an external slided dipole (MESD) with measurements of the total vector of the horizontal component of the electric field of a dipole source at a constant current. The remote sensing is carried out along the profile at four distances of 500 - 2000 m on both sides of the source dipole, with a pitch of 500 m, and the source dipole (length from 395 to 517 m, an average of 480 m) moves along the profile in 4500 m steps. The length of the profile along the straight line was 116 km and 125 km, taking into account the tortuosity of the road network. Due to the inability to perform measurements within the city of Sortavala, 8 km are missed (from 82 km to 90 km from the beginning of the profile - Hiytola settlement). The most pronounced anomaly of low resistance at the distances 40-50 km profile from beginning, and in the depth of about 1.5 km from the surface. There are anomalies in the area of 52-56 km in the depth interval 500-1500 m. And if the first - the brightest anomaly is characterized by immersion from east to west, then the second - a narrower in the range of depths, falls from west to east. The assumption of the multilevel structure of the Ladoga anomaly, which was earlier proposed by B.N. Klobukov, looks highly likely.
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SEISMOACOUSTIC TOMOGRAPHY ON JET GROUTING
Shmurak Denis1, Shishkina Mary2
1 – Geological Faculty of Lomonosov Moscow State University, department of seismometry and geoacoustics
2 – The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS)
Interwell seismoacoustic tomography takes a special place amongst so called “hidden” methods as In urban development. Interwell seismoacoustic tomography is a reliable and very informative method for surveying geological environment. Fundamentally important features of this method are the approximation of the source and receiver to the object under surveying, as well as the detachment from the day surface, characterized by high heterogeneity, sometimes with the complexity of the relief, and a high absorbing capacity, which has a huge influence on the waveform and the possibility of operation. Interwell tomography have no competitors among other geophysical methods in situations where there is no access to the relief surface, or it is difficult (surveying of soils under buildings, surveying in dense housing); when it is required to have a high accuracy of the border fretting and to search for small irregularities in size and contrasts (search for karst cavities at great depth). In this paper several sophisticated niceties of interwell seismoacoustic tomography are illustrated on examples of applying this method for control of quality of jet grouting. The jet grouting technique has become very popular all over the world as a practical means for solving several geotechnical problems and it is important to develop methods of controlling its quality.
2D MODELING OF AMT DATA ON THE LADOGA AND PECHENGA STRUCTURES
Skorokhodov A.A.
Geological Institute KSC RAS, Apatity, Russia
The AMT (audio-magnetotellurics) method was applied to solve structural problems at western flank of the Pechenga structure of electrical conductivity and at the Janisjarvy fault zone of the Ladoga anomaly. The purpose of these studies was to determine the angle of inclination and depth of the conductors which were found by DC methods. Analysis of the observed AMT data showed that objects can be approximated by two-dimensional models. To calculate the response of an AMT field, the finite difference method is used, implemented by I.L, Vardanyants. During modeling, the influence of the inclination angles of the conductive layers, the depth of their bedding and flattening, and the influence of the anisotropy of electrical conductivity were established. Also, when selecting models, the TE-mode of the EM field (when an electric field is directed along the homogeneity axis) was taken into account firstly, as is reflected by the deep distribution of electrical conductivity. And only at the last, refining stages, TM-mode, which is subjected by the influence of near-surface inhomogeneities, was taken into account. The simulation results showed that the Janisjarvy anomaly is probably a local near-surface conductor. The Pechenga structure on the western flank is an alternation of high contrast resistivity layers, steeply dipping in the southwest and flattening at a depth of about 2 km.
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ON THE NATURE OF THE LADOGA CONDUCTION ANOMALY - GRAPHITES AND (OR) FLUIDS? Zhamaletdinov A.A1,2, Sokolova E.Yu.3,4, LADOGA Working Group 1 – Saint-Petersburg Filial of IZMIRAN. 2 – Geologial inst. of KSC RAS, Apatity 3 - Schmidt Institute of Physics of the Earth, Russian Academy of Sciences (IPE RAS), Moscow 4 - All-Russian Research Geological Oil Institute (VNIGNI), Moscow [email protected], [email protected]
The structure and nature of Ladoga anomaly has been the object of research for more than 40 years. In recent years, significant progress has been made thanks to the synchronous MT-MV profiling carried out by the LADOGA working group on the Vyborg-Suojärvi trace [Sokolova et al., 2016], as well as the shallow DC profiling with the use of multi electrode installations in combination with AMT soundings [Zhamaletdinov et al., 2018]. High electrical conductivity of the upper part of the section (up to 1-2 km) has been explained by the presence of electronically-conductive sulfide and graphite-bearing rocks. The most popular hypothesis about the nature of the deeper part of the anomaly (about 20 km) was a fluid one, presented by B.N. Klabukov (2006). However, this treatment faces a whole series of contradictions in the terms of petrology, rheology, information on the heat flux, etc. [Yardley & Valley, 1997; Artemieva, Shulgin, 2015; Pavlenkova, 1996; Karakin et al., 2002]. The modern MT-MV sounding experiment of the LADOGA group, made it possible to construct a new sufficiently resolved model of Lake Ladoga anomaly resistivity cross-section. In this model the deep conductivity structure is represented by a series of inhomogeneous conductive tectonic plates gently dipping to SW and interpreted as a series of thrusts developed along the Early Proterozoic formations containing graphite in their composition by [Mints, Sokolova et al., 2018]. At the same time, graphite plays the role of "lubricant", which facilitates the slipping of Proterozoic metamorphic plates during accretion (thrusting) of to the edge of the Karelian craton in the Svekofenian time and later.
LITHOSPERIC CURRENT SOURCES AND THEIR IMPACT ON POWER GRIDS
Vakhnina V.V., Gorokhov I.V.
Togliatti State University
[email protected], [email protected]
Powerful current source in a sial zone of the Earth, which are formed near the seismic centre are known for a long time [1-3]. The beginning of the earthquakes is accompanied by a complex of various powerful electromagnetic phenomena [2-4]. The importance of the earthquakes prognostication is the reason why almost all the researches of the lithospheric current sources are connected with the searching of the earthquakes premonitory symptoms [3-5]. At the same time in the descriptions of the development of major accidents at electrical power generating system objects some phenomena attributed to the earthquakes premonitory symptoms and also the increasing of the reactive power consumption which is typical for a quasi-currents occurring can be noticed [1]. For the first time ever an assumption about a negative effect of the lithospheric current sources on the power generating sets and power transformers work was discussed in the work [1], where it is shown that a quasi-current can be a prime cause of the Sayano–Shushenskaya power station accident.
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Detected impulses of the lithospheric current sources can last from several minutes to several hours and sometimes even for several days [2,5]. It was discovered that the telluric current density and thus the radial component of the electrical intensity at the Earthquake surface is decreasing in inverse proportion to the cube of the distance to the lithospheric current sources. Generally, the powerful electricity transmission line length is hundreds of kilometers, and that is why the lithospheric current sources can affect only one object of power grid. The occurring of the lithospheric current sources nearby the solid grounded neutral electrical substations can energize in PTW a quasi-current that is able to provide a core saturation. Assessments showed that the danger for the power grid work can cause the lithospheric current sources that are formed at a depth of not more than 20 km [6]. As the lithospheric current sources are connected to the seismic centre [3], the danger for the power grid work can cause the earthquakes, which geocentre is at a depth of not more than 20 km. The earthquake effect of such seismic centres may be negligible, but the influence of the lithospheric current sources can lead to the malfunction of the powerful objects of the high-power station. High-power stations and major substations are often placed nearby the major rivers. These river flow along the fault lines, where the possibility of the seismic centres formation is high. As a result, a considerable part of the major substations are posed at a risk of the lithospheric current sources influence. 1. Селемир, В.Д. О вероятных причинах и сценарии развития аварии на Саяно-Шешунской ГЭС; монография/ В.Д. Селемир и [др.]. Тольятти, Изд-во ТГУ, 2015. – 66с. 2. Воробьев, А.А. Физические условия залегания и свойства глубинного вещества. Высокие электрические поля в земных недрах / А.А. Воробьев. Томск: Изд-во ТГУ, 1975. – 298 с. 3. Сурков, В. В. Электромагнитные эффекты при землетрясениях и взрывах : монография / В.В. Сурков. – М.: Изд-во МИФИ, 2000. – 237 с 4. Смирнов С.Э. Особенности отрицательных аномалий квазистатического электрического поля в приземной атмосфере на Камчатке / С.Э. Смирнов // Геомагнетизм и аэрономия. - 2005. - Т. 45. - № 2. - С. 282-287. 5. Соболев, Г.А. Физика землетрясений и предвестники/ Г.А. Соболев, А.В. Пономарев. М.: Наука, 2003. - 268 с. 6. Вахнина, В.В. Источники квазипостоянных токов и их воздействие на функционирование систем электроснабжения / В.В. Вахнина, В.В. Горохов, И.В. Горохов // Промышленная энергетика. – 2016. – №5. – С. 12–18.
INVESTIGATION OF SIGNALS OF GEOACOUSTIC EMISSIONS AND ELECTROMAGNETIC RADIATION IN EXPLORATION AND DEEP WELLS
Alexey Vdovin, Yurie Astrakhantsev, Nadejda Beloglasova and Evgenia Bajenova
Institute of geophysics UB RAS, Russian Federation
Study of fracture zones and rock crushing, the identification of tectonic disturbances is an important task in the research of the tectonics of ore deposits. These zones are defined by a complex of geophysical methods in wells. As a rule, they make it possible to judge about already formed zones of disturbance. Research into the background geoacoustic emission (GAE) and natural electromagnetic radiation (NEMR) in sections of deep wells has shown that the maximal signal levels of both geneses mostly coincide spatially by their depths with intervals of higher fracturing of rocks. In-well measurements in GAE and NEMR have certain peculiarities and restrictions. It should be noted that a well proper has an influence on the appearance and evolution of fracturing in the massif of rocks. The boring process causes a substantial increase in the density of defects in the near-well volume, 45 especially when fractured rocks are drilled. This is a favorable factor for emission intensity to be increased in the sequel. Moreover, a well with broken rocks is a concentrator of both quasi-static and variable stresses, which influence the initiation and development of fractures in the volume of the medium. For measurements, we used a program-apparatus complex developed in the Institute of Geophysics, Ural Division, Russian Academy of Sciences, which enables simultaneous recording of GAE in three frequency ranges (100-500, 500-5000 and 2500-5000 Hz) and NEMR at three frequencies (45, 80 and 120 kHz). The sampling cycle is two seconds for all sensors. At every single point, measurements are carried out and consist of ten cycles. An example of the allocation of intervals of fractured rocks can serve as measurements performed in the Arakayevsky parametric well (Sverdlovsk region). The set of standard geophysical methods stands out cavernous interval with low density properties at depths 1545-1910 m. On measurements of GAE and NEMR it was established that this interval is dynamically active. This is technologically dangerous and in the future, rock falls are possible. In the Onega Parametric Well (Karelia), the contact of rock salt deposits with the granitoid massif at 2940 m depth was notable for GAE and NEMR anomalies. This contact is an interval of broken (fractured) rocks differing by durability properties. Simultaneous measurement in GAE and NEMR in wells when studying fractured rocks enable us to obtain information on manifestation of deformation processes in fields with varied physical nature, and, consequently, to determine zones of high tensosensitivity, favorable for monitoring of geodynamic phenomena in the Earth’s crust. This work was partially supported by the project UB RAS № 18-5-5-52.
POSSIBILITIES OF THREE–COMPONENT GEOACOUSTIC LOGGING AT HYDROCARBON DEPOSITS
Alexey Vdovin, Nadejda Beloglasova, Yurie Astrakhantsev and Evgenia Bajenova
Institute of geophysics UB RAS, Russian Federation
The geophysical method of oil-gas borehole investigation devised at the Institute of geophysics UB of RAS studies characteristics of geoacoustic emission (GAE) over the frequency range of 0.1÷5 kHz which displays peculiarities of fluid-gas dynamic processes in a volume of geological environment. More over: 1. The second displacement derivative (acceleration) of borehole walls’ vibrations is recorded. 2. The three-component system of orthogonal transducers-accelerometers in a protecting casing of a borehole instrument with the diameter of 40-42 mm enabling to divide geoenvironment microvibrations into three directions is applied. 3. Frequency composition of recorded geoacoustic signals is analyzed. 4. Values of measured and calculated parameters representing distribution of signal amplitudes according to three components at four frequency bands are evaluated. Three-component geoacoustic logging at hydrocarbon deposits solves the following problems: Estimation of fluid saturation character at a qualitative level; Detection of fluid flow outside and inside the casing string with division into fluid types; Detection of fluid flow position in chambers of a cement ring with division into fluid types;
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Detection of non-sealed points of borehole equipment; Location of gas-water, gas-oil and water-oil contacts; Study of inflow section in a perforated interval of casing string which determines the boundaries of efficient intervals; Detection of sections with high absorption of drilling fluid in an open shaft; Test for leaks of the column (together with thermometry); Detection of intervals of fluid movement in horizontal direction outside a casing string within seams Detection of industrial deposits; Revelation of water-flooded intervals of a hydrocarbon deposit. Transducers-accelerometers with relative coefficient of transverse conversion not more than 6% allow confident division of signals into three directions. Transverse sensitivity of a transducer is determined by its maximum sensitivity to oscillations in a direction perpendicular to its main axis that is parallel to the surface where it is placed. The equipment has sensitivity that enables to record an acoustic response of geoenvironment to deformations in the order of 10-8 – 10-11 m. Geoacoustic signals in sedimentary rocks are recorded by three orthogonal transducers-accelerometers of PVT type (piezoelectric vibromeasuring transducer). Transducers with coefficients of conversion not less than 6-10 V*s2/mm are installed into a borehole instrument. Amplitude level of signals at different frequency bands is presented in units of recorded acceleration mm/s2. Small amplitude of geoenvironment microvibrations is an additional optimum condition to divide signals from three directions. Thus, signals from three directions are fixed at preset depth in a borehole which makes it possible to compare their amplitude at different frequency bands.
STATISTICAL RELATIONSHIPS BETWEEN VARIATIONS OF THE GEOMAGNETIC FIELD, AURORAL ELECTROJET, AND GEOMAGNE- TICALLY INDUCED CURRENTS
A.V. Vorobev1, V.A. Pilipenko2,3, Ya.A. Sakharov4, V.N. Selivanov5
1 – Ufa State Aviation Technical University, Ufa
2 – Institute of Physics of the Earth of the Russian Academy of Sciences, Moscow
3 – Geophysical Center of the Russian Academy of Sciences, Moscow
4 – Polar Geophysical Institute of the Russian Academy of Sciences, Apatity
5 – Center for Physical and Technical Problems of Energy of the North, Russian Academy of Sciences, Murmansk
One of the most significant manifestations of the space weather is the excitation of geomagnetically induced current (GIC) in conducting technological systems during magnetic storms and substorms. Modern power transmission networks with complex topology are in fact a giant antenna electromagnetically coupled to the currents of the Earth's ionosphere. We examine statistical relationships between variations of geomagnetic field, intensity of auroral electrojet, and GIC, using data from the magnetometer array IMAGE and the records of GIC in the electric power line at Kola Peninsula. The GIC 47 intensity is found to have a highest correlation with the field time derivative dB/dt, whereas correlations of GIC with dX/dt and dY/dt are nearly the same. The latter fact indicates on the quasi-isotropic character of the magnetic field variability. Diurnal variations of geomagnetic field variability dB/dt and GIC intensity have wide night maxima associated with the electrojet, and morning maxima presumably caused by intense geomagnetic pulsations of the Pc5-Pi3 type. Statistical distributions of the probability density of AE-index correspond to the generalized Pareto distribution, while distributions of magnetic disturbance, variability |dB/dt|, and GIC better correspond to the log-normal distribution. On the basis of constructed distributions the probabilities of extreme values of these parameters have been estimated. The linear regression model has been developed which enables one to estimate the GIC magnitude from a current value of the time derivative of geomagnetic field or AE-index. This study is supported by the grant from the Russian Science Foundation No. 16-17-00121.
ABOUT THE INFLUENCE OF GEOMAGNETIC ACTIVITY ON METROLOGICAL CHARACTERIS-TICS OF MAGNETIC INCLINOMETRIC SYSTEMS Vorobeva G.R., Vorobev A.V. Ufa State Aviation Technical University, Ufa., Russia [email protected] It is known, that effective development of the Earth's interior is hardly possible without the use of modern high-precision underground navigation systems. So, various kinds of inclinometric studies conducted on the cable in oil and gas wells are one of the most important components of the whole process of drilling a well. At the same time the sensitivity threshold of modern geophysical magnetosensitive information- measuring systems (IMS) is comparable, and in many cases significantly lower than the amplitude range of natural variations of the geomagnetic field (GMF) caused by geomagnetic activity (GMA). As a result, for this and other reasons, specialists in geophysics, instrumentation, metrology and other related fields of high technology manufacture are paying increasing attention to monitoring, forecasting, analysis and minimizing additional errors that arise in the magnetosensitive equipment in operation during the GMA. The paper is concerned with study of GMA (disturbed variations of GMF) influence on the metrological characteristics of magnetic inclinometric information-measuring systems, widely used in geophysical surveys in oil and gas wells. Also on the basis and in accordance with the standards, technical instructions and normative documents in this branch of the national economy mathematical models are developed and criteria are formulated for both qualitative and quantitative assessment of the degree of GMA impact on metrological characteristics of magnetic inclinometer equipment. Also, special indices of GMA are offered that allow to evaluate (including in the field conditions) the effect of this influence quickly and with minimal effort, which obviously takes place both during calibration and verification, as well as during operation of precision magnetic inclinometer equipment. The results of a numerical experiment on the example of geomagnetic data (provided by the network of magnetic stations INTERMAGNET) on the basis of models, criteria and indices of GMA described in the paper are presented and discussed.
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SAMOYLOVSKY ISLAND - NEW INTERNATIONAL POLAR RESEARCH STATION; FIVE YEARS UNDER OPERATION OF IPGG
Igor Yeltsov
IPGG SB RAS, Novosibirsk, Russia
Scientific research station “Samoylov Island” was built in 2010 by the decree of the Government of Russian Federation in order to boost Arctic environment studies. Trofimuk institute of Petroleum Geology and Geophysics (IPGG) of Siberian Branch of Russian Academy of Sciences (SB RAS) serves as an operator of the station since 2012. Since 2013, the station operates in a full-year regime. It is equipped with a set of modern scientific instruments and tools, which are required in different fields of research (bio- and geochemistry, geophysics, climatic studies, hydrology, etc.). Speaking of accommodation, the station provides very high level of comfort, standing in a row with best world analogues. Siberian Branch of RAS (SB RAS) together with Far East Branch of RAS, Arctic and Antarctic Research Institute of Russian meteorological service (AARI), North-East Federal University, Alfred Wegener Institute of Polar and Marine Research (AWI) and a number of other partners develops a joint Arctic research program “Integrated Studies of the state and evolution of Siberian Arctic environment”. The main goal of the program is to organize and perform a multidisciplinary research in the following directions: geocryology (permafrost research); paleogeography; climate and paleoclimate; hydrology and hydrobiology; geomorphology and quaternary geology; soil science, microbiology and gas emission from permafrost soils; geophysics and zoology and biology as well. Scientists from IPGG SB RAS has made a large input into permafrost studies in Lena Delta using a set of geophysical methods: aerial imaging, magnetic measurements, electrical resistivity tomography electromagnetic imaging, thermal monitoring etc. Annual expedition on Samoylovsky island, performed by a joint field party from the Institute of Petroleum Geology and Geophysics and Novosibirsk State University is a good example of the interdisciplinary approach towards the solution of the sophisticated task of Arctic research. This expedition introduced modern geophysics and rich experience of Novosibirsk geologists, paleonthologists and paleomagnethologists, botanicists and soil scientists to permafrost research in Lena Delta. A number of interesting objects, common for Arctic region were studied: thermokarst lakes, alases, (drained basins of thermokarst lakes), pingos, lake and channel taliks, erosional valleys, yedoma sediments, degrading subsea permafrost and many others. Together with colleagues from other countries (Germany, Finland, Canada, USA, Japan, Sweden and others) we work on data processing and interpretation as well as publication. Scientists from Novosibirsk with their fruitful work raise the quality of Arctic research to the new level. This is especially important in the country, where permafrost covers the major part of the surface. It is safe to say, that this direction of studies is going to be dominating for the next 50 years.
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JOINT INTERPRETATION OF GEOPHYSICAL AND GEOCHEMICAL FIELDS BASED ON THEIR ANALYTICAL CONTINUATION DOWN.
Ermokhin Konstantin M1, Zhdanova Ludmila A.2
1 - Pushkov institute of terrestrial magnetism, ionosphere and radio wave propagation of the Russian Academy of Sciences, St.-Petersburg Filial (SPbF IZMIRAN),
2 - NPP “Analytical Geophysics”, St. Petersburg.
A joint (complex) interpretation of data from various geophysical methods is significantly more reliable than a separate method. As a rule, it is based on the assumption of the existence of any correlation fields or physical parameters, therefore almost all these methods are based on the apparatus of mathematical statistics. The existence of regression dependencies between the physical properties of rocks is often a debatable issue. In separate ore or hydrocarbon provinces, such local connections are most often not in doubt, and reliance on reference objects is justified. At the same time, there are no common global regular relationships between physical parameters and fields. This was repeatedly noted by many researchers. One of the possible ways of supplementing existing methods of integration is the application of the method of analytic continuation of the fields observed on the surface of the fields down towards their sources. The universality of this approach is based on the generality of the description of fields used in geophysics and geochemistry by partial differential equations of the second order. The commonality of all of them is that they allow an analytical solution.Analyticity is understood in the sense of Weierstrass: the possibility of their representation by power series in space variables, according to the Gauchy-Kovalevskaya theorem. Usually an analytical continuation is said about potential fields (gravitational, magnetic, DC field). In this case, the methods rely heavily on solutions of the Laplace equation. This significantly reduces the scope of the method, which is already limited in view of the decay of the field at the depth of the singular point closest to the surface. We have developed a universal method of analytic continuation - ACCF (analytic continuation by continued fractions). It is based on the transformation of power series into continued fractions. Since the real fields have singularities in the source domain, they can not be adequately described by linear constructions that do not turn to infinity in the final domain of the solution search. And since a continued fraction is a rational function, the zeros of its denominator turn out to be poles of the investigated field function in the lower half-space, which coincide with its sources. Separately, it should be noted geochemical fields, which are described by the diffusion equation, whose solutions do not satisfy the conditions of the Gauchy-Kovalevskaya theorem. But since geochemical processes of formation of deposits occur on a geological time scale, in fact, within the limits of 50-100 years, they can be considered stationary, i.e. satisfying the Poisson-Laplace equation. Therefore, the ACCF method is quite applicable to geochemical fields. The complexification is carried out on the basis of a comparison of the depth, location and configuration of the sources of the various fields. The coincidence of these parameters for two or more methods significantly increases the reliability of the results of the interpretation of geophysical and geochemical research data up to direct prospecting of deposits of ores and hydrocarbons.
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EXPERIMENTAL VERIFICATION OF METHOD FOR MEASURING THE EFFECTS OF INDUCED POLARIZATION OF DEEP OBJECTS IN NATURAL ELECTROMAGNETIC FIELDS
Ermokhin K.M., Kopytenko Yu.A., Petrishchev M.S., Sergushin P.A.
Pushkov institute of terrestrial magnetism, ionosphere and radio wave propagation of the Russian Academy of Sciences, St.-Petersburg Branch (SPbF IZMIRAN)
Interest in measuring the parameters of the induced polarization with the use of natural electromagnetic fields has recently increased. Due to the fact that the depth of the induced polarization (IP) method (caused by polarization) when using generator sets (artificial field excitation) is limited of 300-500 m. The depth of investigation increases substantially when measuring natural electromagnetic fields. Such depth is not enough for the oil and gas complex where hydrocarbon deposits are located at depths of 2-4 km. Prospects for the IP method for direct searches for hydrocarbon deposits (hydrocarbons) have been proved by V.S. Moiseyev and V.M. Berezkin. The main search method of hydrocarbons is seismic exploration that has the efficiency is 50-60%, with the addition of IP it increases to 90%. The method developed by us consists in measuring the phase shift of a natural long-period signal in the presence of IP. The vertical component of magnetic field is measured, which is not used in the magnetotelluric sounding method (MTS). MTS method theory is assumed that the vertical component is absent in the incident wave, and its presence is due only to telluric currents. The proposed method is more technologically advanced for the solution of the hydrocarbon search problem, however, only local objects are distinguished without the definition of the horizontal-layered structure of the section. A special feature of the method is the synchronous measurement at several points on the profile. However, since the object of the search is a deposit, this has little effect on the effectiveness of geophysics. In addition, the absence of the need to measure electrical components removes the complexity of their measurement and the influence of near-surface inhomogeneities. The essence of the method reduces to the fact that the phase shift of the IP signal is practically independent of frequency, and the phase shift due to induction is directly proportional to the frequency, as shown by M.S. Zhdanov. The phase of the reference signal is difficult to determine, but with the aid of a difference scheme one can obtain a result. The response of the medium to the k-th harmonic of the polarizing field (telluric currents) consists in changing the amplitude and phase shift: 2 it() in ip T kk k in ip k aek where k is the induction phase shift of the k-harmonic. - k phase in 2 ip shift IP is directly proportional to the frequency, i.e. k (μ-induction parameter), and Tk k ip does not depend on the frequency, i.e. k . Since the phase of the reference signal is undefined, but the measurements are synchronous, we use a difference scheme. We calculate the phase shift of the response of the medium at two points 1 and 2 - R1(t), R2 (t), not far from each other (of the order of 200-500 m), for some harmonic n. In synchronous measurements, because the signal is in phase with the remote source of the polarizing field, the k-th harmonic phase is the same. The difference in phase shift between points 1 and 2 is 12 n ()() 2 1 2 1 .
So we get a linear frequency function, with a constant component 21 and a linear coefficient
21 . Having constructed the curve ii1 i = 0 ... N along the profile (N is the number of points on the profile) and integrating along the observation line, we get: 51
k k() j1 j C , i.e. in fact, a curve of induced polarization along the profile j0 up to a constant factor and an unknown term C (which is not used to construct the section by the method of analytic continuation of the field to the sources). A geologically meaningful result was obtained in 2017 in the process of tests on the Lehta structure in Karelia.
ON THE BOUNDARY BETWEEN THE BRITTLE AND DUCTILE PARTS OF THE EARTH'S CRUST
Zhamaletdinov A.A.1,2
1 – Geological Institute KSC RAS, Apatity
2 – Saint-Petersbourg Branch of IZMIRAN
The deep CS AMT soundings indicate the boundary of sharp increasing of resistivity in the Earth's crust at the depth of about 12 km . We named it as boundary of impermeability (BIP-zone). BIP zone divides the Earth’s crust on the upper (brittle) and lower (ductile) parts. The upper part of the Earth crust of 10-12 km thickness is heterogeneous. Its heterogeneity is explained mainly by the wide spreading of sulfide and carbon bearing crustal anomalies of electronically conductive nature and by presence of intermediate conductive layer of dilatancy-diffusion nature (DD-layer) of fluidal nature having the regional spreading on the Fennoscandian shield. The low crust of 20-30 km thickness is of high resistivity (105-106 Ohm∙m) and is horizontally homogeneous. It can be depicted by the “normal” electrical section obtained in frame of FENICS experiment. It is named as compaction zone having semi-ductile properties. At the depth of about 12 km the "BIP” zone coincides with the boundary of “irresistibility” (BIR zone), that has been met in the Kola super deep well SG-3. Due to this reason (high worsening of drilling conditions) four damages happened in four drilling shafts of SG-3. Compaction and increased viscosity of rocks at 12-th km and deeper is explained by elimination of tangential stresses, existing in the upper crust. So, we quantitatively have found an important rheological parameter, brittle-ductile transition zone (BDT - zone after Moisio, 2005). Earlier that parameter has been estimated only qualitatively on the base of laboratory study of rock properties at high P-T conditions and seismic data on location of the earth-quake epicenters.
EXPERIMENT "MURMAN-2018" ON THE STUDY OF THE DEEP GEOELECTRIC BOUNDARIES IN THE EARTH'S CRUST WITH THE USE OF DC AND INDUCTION SOUNDING METHODS
Zhamaletdinov AA1,2,3, Shevtsov AN1, Skorokhodov AA1, Kolobov VV3, Ivonin V.V.3
1 - Geological Institute KSC RAS, Apatity 2 - St. Petersburg Branch of IZMIRAN 3 - Center for Energy of the North KSC RAS, Apatity [email protected]
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The Murman-2018 experiment on the deep electromagnetic sounding with the use of natural and controlled sources was carried out in June 2018 on the territory of Murmansky Archaean block. The study of proposed boundary of high resistivity (the boundary of "impermeability") at a depth of about 10-15 km, from which the basement position of the upper part of the Earth’s crust is associated, was the main objective of the Murman-2018 experiment. The soundings have been performed with the use of distance and induction approaches. Car generator “Energia-4” with a capacity of 29 kW and two mutually orthogonal grounded dipoles each of 1.5 km length were used as a controlled source for frequency (CSAMT) and distance soundings. Distance soundings were performed in the stacking mode. Rectangular different-polar signals in the "meander" mode were generated for that with a period of 0.25 s. Distance soundings were implemented with a linear increasing of distances between the source and receiver with the step of 5 km in the interval from 5 to 50-100 km. CSAMT soundings in complex with AMTS in frequency band from 1 Hz to 1 kHz were performed over a sparse network at separate points of distance soundings, mainly for to take into account static shift distortions. Static shift corrections were estimated by means of comparison of CSAMT apparent resistivity curves obtained from the input impedance and from the field of total horizontal magnetic field.
NEW DATA ON THE NATURE AND STRUCTURE OF THE LADOGA ANOMALY FROM DC AND AMT RESEARCH
Zhamaletdinov A.A.1,2, Shevtsov A.N. 2, Skorohodov A.A.2, Kolesnikov V.Ye.2, Nilov M.Yu.3
1 – Saint-Petersbur Filial of IZMIRAN.
2 – Geologial inst. of KSC RAS, Apatity
3 - Institute of Geology of KarSC RAS, Petrozavodsk
Ladoga anomaly is a part of Ladoga-Bothnian zone (LBZ) with extansion of more then 1000 km . The deep Ladoga anomaly has been firstly discovered in the late 70s by Ukrainian research team (Rokityansky et al., 1981) with the use of magnetovariational method. The anomaly was interpreted as conductive body at the depth of about 10 km. In 70-th and 80-th the anomaly was studied in Russia (Vasin, 1988; Kovtun et al., 1984) and in Finland (Hielt, 1984; Pajunpaa, 1984; Adam et al., 1982). By results of digital 2D modelling it appears as conductive body with the resistivity falling down up to 2-20 Ω∙m at the depth of 20-30 km (Vasin, Kovtun, Popov, 1993). The third stage of study was realized in 2013-2015 by means of integrated magnetotelluric and magnetovariational profiling [Sokolova et al., 2017]. Each of three stages were completed by construction of geoelectrical models at the depth interval of 10-30 km. In this presentation the fourth stage is presented, that has been done in 2015 and 2017 by means of DC electrical profiling with multielectrode installations in complex with AMT soundings. According to results of the fourth stage, an unambiguous conclusion was drawn on the connection of the upper part of the Ladoga anomaly of 130 km width with electronically-conducting sulfide-carbonaceous rocks up to the depth of 0.3 – 0.6 km. The nature of the lower part of anomaly at 10-30 km is connected with graphite containing geological structures [Sokolova et al., 2017].
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SECTION P. PALEOMAGNETISM AND ROCK MAGNETISM
Conveners - Dr. P.V. Kharitonskii, Dr. A.A. Kosterov, Dr. E.S. Sergienko
Paleomagnetic reconstructions Paleointensity Rock Magnetism as Physical Basis of Paleomagnetism
INFLUENCE OF STRESS’ MATRIX ON THE INCLUSION DEFORMATION
Afremov L.L., Anisimov S.V.
Far Eastern Federal Univerity, Vladivostok, Russia
In solving problems devoted to the study of the effect of mechanical stresses on magnetization processes of rocks, it is assumed that the stresses applied to the sample and to ferromagnetic inclusion are equivalent. Obviously, this assumption is based on the intuitive opinion that the stresses transmitted by the rock matrix to the ferromagnetic grain are proportional to the stresses applied to the sample. In this paper, an attempt is made to estimate the dependence of the distribution of mechanical stresses inside the magnetic inclusion on the deformation of a nonmagnetic matrix. All calculations are made in the framework of the following model: The inclusion and the matrix are considered as elastic isotropic medium with elastic Lame constants 휆(푖푛), 휇(푖푛) и 휆(푒푥), 휇(푒푥), respectively. A matrix of thickness 2푙 is bounded by two infinite planes that are subject to uniform compressive loads 푝 oriented along the axis Oz. At a point considerably removed from the boundaries of the matrix, there is a spherical inclusion of the radius 푅. We use the equations of equilibrium of the medium and Hooke's law: 휇 ∆푢 + ∇(∇, 푢) = 0, (1) 휆 + 휇
1 휕푢푖 휕푢푘 휎푖푘 = 휆휀푙푙훿푖푘 + 2휇휀푖푘, 휀푖푘 = ( + ), (2) 2 휕푥푘 휕푥푖 where 푢 = {푢푥, 푢푦, 푢푧} is a displacement vector, 훿푖푘 are symbols of Christoffel and Kronecker, 휀푖푘 stands for an elastic strain tensor, 휀푙푙 = 푇푟(휀푖푘).
In the absence of inclusion, the matrix is subject to uniform stresses 휎̂푖푘 = −푝훿푖3훿푘3, which lead to homogeneous deformation with displacement 푢̂ = {0,0, 푢̂푧 = −푝 (푧/푙)}. The presence of inclusion leads to a change in the deformation of the matrix 푢 = 푢̂ + 푣(푒푥), where 푣(푒푥) is harmonic function vanishing at infinity. We shall seek the displacement 푣 in the form of a superposition of centrally symmetric solutions (푟2, 푟, 1, 1/푟) and their derivatives:
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3 3 (푒푥) 휕 1 휕 1 휕 푣푖 = 푎 휎̂푖푘 ( ) + 푏 휎̂푘푙 ( ) + 푐 휎̂푘푙 (푟). (3) 휕푥푘 푟 휕푥푖휕푥푘휕푥푙 푟 휕푥푖휕푥푘휕푥푙 Substituting (3) into (1) we obtain 푎 = −с (3휆 + 휇)/(휆 + 휇). We construct the solution in the domain of inclusion 푣(푖푛) in such a way that 푣(푖푛)(푟 = 0) = 0:
(푖푛) 휕 1 휕 2 2 푣푖 = 푑 휎̃푖푘 (푟) + 푓 휎̃푖푘 (푟 ) = 푑 휎̃푖푘푛푘 푟 + 푓 휎̃푖푘푛푘 푟 , (4) 휕푥푘 2 휕푥푘 (푒푥) where 휎̃푖푘 = 휎푖푘 (푟 = 푅) are stresses at the matrix-inclusion boundary. The following stress tensor corresponds to the displacement (4):
(푖푛) 2 2 휎푖푘 = 2휇 [푓(휎̃푖푚푛푚푛푘+휎̃푘푚푛푚푛푖) 푟 + (푑 + 푓푟 )휎̃푖푘] + 휆[2푓휎̃푘푚푛푘푛푚푟 + (푑 + 푓푟 )휎̃푚푚] 훿푖푘. (5) Coefficients 푏, 푐, 푑 and 푓 can be obtained from the boundary conditions: (푒푥) (푖푛) (푒푥) (푖푛) 푣푖 = 푣푖 |푟=푅, 휎푖푘 푛푘 = 휎푖푘 푛푘|푟=푅. (6) The solution to this problem makes it possible to determine the stress distribution in the inclusion.
PALEOMAGNETIC, ROCK-MAGNETIC AND GEOCHEMICAL PROPERTIES OF THE RIPHEAN INTRUSIVE BODIES OF THE NORTHERN PART OF THE BASHKIRIAN MEGAZONE (THE SOUTHERN URALS)
Anosova M.B.1, Latyshev A.V.1,2, Khotylev A.O.1
1 – Lomonosov Moscow State University, Geological Faculty, Moscow, Russia
2 – Schmidt Institute of the Physics of the Earth, Moscow, Russia
The studied objects are the intrusive bodies of the mafic composition and Berdyaush rapakivi pluton. They are located in the core of the Bashkirian megazone (the Southern Urals). Their formation is related to the Riphean stage of rift magmatism on the East-European craton. The Berdyaush pluton (consist of syenites and rapakivi granites) and host rocks are cut by dolerite dykes. The U-Pb dating of the Berdyaush granites and syenites yielded the ages of about 1370 Ma (Ronkin. et al. 2005). For the dike we obtained age 1349 ± 11Ma. The host rocks are folded together with the granites of the Berdyaush pluton, while dikes were not subjected to these deformations, we attribute dikes to a later and more shallow stage of magmatic activity. According to geochemical characteristics, incompatible elements contents, La/Yb ratio and TiO2 concentration increase from south to north, indicating the deeper magma source. We also performed the paleomagnetic investigation of the dikes and obtained the new paleomagnetic pole for the high-temperature component of remanence. The obtained pole is located between the published poles for 1265 and 1458 Ma for the East European craton (Lubnina et al., 2009; Buchan et al., 2000). Furthermore, we found MT component possibly of the Later Paleozoic age. The measurements of the anisotropy of magnetic susceptibility demonstrate three types of the magnetic fabric. About 50% of the studied objects demonstrate the N-type of the AMS ellipsoid, when the minimal axis K3 is normal to the contact of intrusion and the other two axis lie in the dike plane. In this case we were able to reconstruct the magma flow lineation. The Berdyaush pluton is bounded by the Bakal-Satka regional fault of NE strike in the west and the dikes related to the Berdyaush pluton demonstrate the shallow magma transport from the west to the east. As
55 the studied dikes are generally transverse to this fault, we assume that it acted as the long-lived magma feeding zone, which controlled the emplacement of mafic dikes and the Berdyaush pluton itself in Riphean. Northward from the Berdyaush pluton dikes are parallel to the Bakal-Satka fault, while magnetic lineation in sills generally has NE strike. Consequently, the emplacement of intrusions was controlled by a regional extension zone parallel to the Bakal-Satka fault. Since the central part of the Riphean rift was located to the south, we assume that the magma flowed in a northeast direction. This work was supported by RFBR (project 17-05-01121). References: Buchan K.L., Mertanen S., Park R.G., Pesonen L.J., Elming S.-A., Abrahamsen N., Bylund G., 2000. Comparising the drift of Laurentia and Baltica in the Proterozoic: the importance of key palaeomagnetic poles. Tectoniphisics 319 (3), 167–198. Lubnina N.V. East European craton in the Mesoproterozoic: new key paleomagnetic poles. Doklady Earth Sciences, 2009. Vol. 428, № 1, p. 1174-1178. Ronkin Yu.L., Matukov D.I., Presnyakov S.L. et al. “In situ” U-Pb SHRIMP dating of the zircons from the nepheline syenites of the Berdyaush pluton (the Southern Urals). Lithosphere, 2005. №1. P. 135-142.
MAGNETIC MINERALOGY OF SAMPLES WITH L-SHAPED ARAI- NAGATA DIAGRAMS
Aphinogenova N.A., Smirnov M.A., Gribov S.K.
Geophysical Observatory "Borok" IPE RAS, Moscow
The Thellier experiments on paleointensity Banc determinations on the Armenian Middle Jurassic basalts revealed a weird behavior of the Arai-Nagata (A-N) diagrams which expresses itself in a sharp drop in NRM intensity when a sample is heated to about 400 °C accompanying by a very weak pTRM acquisition in this temperature region. On contrary, a further increase in temperature leads to sudden change for the sharp increase in pTRM acquisition with almost no NRM decrease creating L-shaped A-N diagrams. Accordingly, the consecutive Msi(T) curves recorded in external field = 450 mT show some degree of thermal instability with omnipresent drop (small or not so small) in Ms intensity after heating to 400 °C.
At the same time, a quick heating straight to 600 °C reveals only a phase with Tc 550 °C which is stable to heating up to 700 °C. Thermodemagnetization of Mrs and ARM indicate similar drop in intensity of both magnetizations by heating to 400 °C, that is, long before reaching Tc proving that the nature of sharp drop in NRM cannot be explained simply by its partial destruction due to possible metamorphic processes. As is shown by X-ray data, the samples contains initially a low-Ti oxidized TM grains which undergo further single-phase oxidation (SPO) during thermal treatment. Note that heating powder specimens already to 200 °C yields precipitation of some amount of hematite. So, the working hypothesize is that the observed sharp decay in Mrs, NRM and ARM, when the heating temperature approaches 400 °C, reflects the DS rearrangements because of appearance of cracks due to developing of deep SPO phase following by generation of hematite inclusions (lamellae) due to onset of heterophase oxidation. In its turn, the intensive growth of pTRM on the background of practically stopped NRM decay at higher temperatures is most likely due to a decrease in effective sizes of TM grains with a corresponding increase in the efficiency of acquiring pTRMs. Noteworthy that heating powder specimens to 525 °C increases the content of hematite up to 20-50 % but still at least a half of the material displays spinel structure with low cell parameter 0.832-0.835 nm which points to amazingly strong thermal stability of remnants of highly oxidized TM regions.
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CHARACTERISTICS OF THE MAGNETIC SUSCEPTIBILITY OF SPIN GLASSES
Belokon V.I., Chibiryak E.V, Trofimov A.N, Dyachenko O.I.
Far Eastern Federal University, Vladivostok
The long-term relaxation of the magnetic moment of spin glasses can be one of the reasons for the formation of a viscous magnetization of rocks, so studying its reaction to the inclusion of a weak magnetic field is of undoubted interest. In this article, the magnetic susceptibility and specific heat of spin glasses are investigated in the Ising model approximation using the random interaction field method [1]. Using known approximations [2] for a two-sublattice magnet, we can write the following system of equations:
B B 1 1 m 1 2 m Mtanh 1 H M H M H h dH , Mtanh 2 H M H M H h dH , 12B kT 1 1 011 2 012 1 22B kT 2 2 022 1 021 2 1 B1 2 B2 (1) where m1 and m2 are the magnetic moments per atom in the first and second sublattices, respectively, h is the external field, H011 and H022 are the fields from the atoms of the nearest neighbors for the first and second sublattices, H012 and H021 determine the interaction of the atoms of different sublattices, M1 and М2 are the relative magnetization per atom for the first and second sublattices, k is Boltzmann constant, Т is the temperature, B1 and B2 are dispersions in the distribution function of the random fields of exchange interaction [1]. Further consideration is limited to equivalent sublattices with competing interactions, for which the results of computer simulation are known [3]. In this case, the equations for the moments of the distribution function are as follows:
H K1 z K z , B2 2 K 2 1 z K 2 z , (2) 0 1 2 1 2 where K1 is the positive exchange integral, K2 is the modulus of the negative exchange integral, ν is the relative fraction of atoms with the negative exchange interaction, z is number of the nearest neighbors.
Magnetic ordering is possible under the condition HB0 /1 and if H0>0 - this is ferromagnetism , H0<0- this is antiferromagnetism, HB0 /1 - this is spin glass state. The following relations are obtained:
The magnetic susceptibility of the spin glass (m1 m2=1, k=1) is determined by means the following formulas 11BB tanh tanh BTBT ,H 0 and , H 0 . (3) H BH00 1 0 tanh 0 B 1 tanh BT BT The magnetic susceptibility of an antiferromagnet:
1 BBB HM22 tanh00 tanh tanh3 2 BTTT BT , (4) HHMBBB 32 10 tanh 0 0 tanh tanh3 2 BTTT BT if T
Acknowledgments. This work was financially supported by the State Program of the Ministry of Education and Science of the Russian Federation № 3.7383.2017/8.9. References V. Belokon, K. Nefedev, Distribution function for random interaction fields in disordered magnets: Spin and macrospin glass, Journal of Experimental and Theoretical Physics 93 (1) (2001) 136-142. V. Belokon, V. Kapitan, O. Dyachenko, The combination of the random interaction fields' method and the bethe-peierls method for studying two-sublattice magnets, Journal of Magnetism and Magnetic Materials 401 (2016) 651-655. G. Petrakovsky, Spin glasses, Soros Educational Journal 7 (9) (2001) 83-89.
FIRST MAGNETOSTRATIGRAPHIC DATA ON THE UPPER CAMBRIAN OF THE KEY SECTION OF THE CHOPKO RIVER (NW SIBERIAN PLATFORM)
Chmerev V.S., Pavlov V.E., Rudko D.V.
The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS)
Sedimentary (mainly carbonate) rocks of Cambrian age outcropping along the valley of the Chopko river (Northwestern Siberia, Norilsk region) represent one of the most important key sections of the Upper Cambrian of the Siberian platform. From the bottom to the top, this section, which thickness is about 1400 m, is divided into two parts: Chopko Formation and Tukalanda Formation. During the field season 2018 we have carried out the sampling of the upper part of the Chopko Fm and the whole Tukulanda Fm for magnetostratigraphic studies. The main purpose of our study is to obtain new information on the geomagnetic reversal frequency at the end of the Cambrian on the eve of the Lower Ordovician superchron of reversed polarity (Moyero superchron). In this report we present the results of laboratory studies of the gathered collection and estimate the prospects of the section for obtaining of the detailed record of the changes of geomagnetic polarity during Late Cambrian.
THE FIRST PALEOMAGNETIC AND PETROMAGNETIC DATA OF TAKYR DEPOSITS IN WEST TURKMENISTAN
Elena Degtyareva
The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS)
During past few decades, petromagnetic methods have been proven as an effective tool for analyzing problems related to the climate and environmental changes. The aim of this study is to investigate the perspectivity of petromagnetic characteristics of sedimentary sequences for the paleoclimatic reconstructions on the territory of Central Asia (in particular, Turkmenistan) during the last five millennia. The most promising methodology for these purposes is to investigate the evolution of the coercivity spectra and thermal demagnetization curves along the sedimentary sequences. The proximate complement to this method is to study the evolution of the other petromagnetic parameters (e.g. different types of the magnetic susceptibility) through the sequence. The object of the present study is represented as a 5-m thick sequence of Takyr deposits dated from the late Holocene, situated in Danata region 58
(Karadag piedmont, Western Turkmenistan). The peculiar feature of this sequence is the thin lamination (varvs), where each layer represents one year of sedimentation. The dating of the sequence is based on the superposition of annual varvs. According the varv chronology, the sequence has been deposited for approximately 5000 years. We will present the preliminary paleomagnetic results, obtained from the pilot batch of samples. The analysis of the demagnetization curves revealed two ferromagnetic components. We estimated the contribution of the paramagnetic, superparamagnetic and ferromagnetic components to the entire signal through the sequence. The analysis of this contribution gives the possibility to investigate material input changes and the autigenic minerals occurrence. Studying the magnetic components susceptibility variations gave us the possibility to reconstruct the depositional conditions. We also made correlation between the petromagnetic properties and varv chronology along the sequence. Preliminary results of the the comparison between the petromagnetic data and the sequence chronology and lithology helped us to make conclusions on paleoclimatic conditions during the sequence deposition.
THE SUBDUCTION ZONES EFFECT ON THE STRUCTURE OF THE SMALL-SCALE CURRENTS AT CORE-MANTLE BOUNDARY
Demina I., Gorshkova N., Ivanov S., Merkuryev S.
St-Petersburg Filial of Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio wave Propagation (SPbF IZMIRAN)
In this paper, we examine the relationship between a kinematic of the small-scale current systems near the core-mantle boundary and high-speed anomalies of seismic waves in the lowest mantle associated with subduction zones. The macro model of the main geomagnetic field sources was early constructed by the authors. Along with west drifting sources two sources were obtained, whose trajectories have a complex shape. One of them is geographically located near the western coast of Canada (Canadian source) and the second one is located in the vicinity of Sumatra (Sumatran source) Both areas are related to subduction zones. Besides, these areas are characterized by existence of extensive coherent regions with increased velocities of seismic waves in the lowest mantle. For the comparative analysis we used the S362ANI and SAW642 models of the seismic velocities heterogeneities and smoothed trajectories of Canadian and Sumatran sources. It was found that the Canadian source trajectory, obtained for period from 1900 year to recent time, passes along a high-speed anomaly in the lowest mantle. Unfortunately, only in some earlier epochs we were able to obtain the parameters of this source. And only certain points of the trajectory around 1600 we were able to add to trace the development of the source. Despite this, the results obtained suggest that the substance of the liquid core, mixing with the matter of the lowest mantle, rises along the lower mantle channel and promotes its further increase. Also the source trajectory reflects the shape of the small-scale channel in the lowest mantle. As for the Sumatra source, it is localized and moves in the thickness of the liquid core on the majority of the time interval considered. However, the western drift is completely absent for this source. Moreover, its trajectory is characterized by series of loops with rising and lowering. The trajectory almost completely passes near the powerful high-speed anomaly in the lowest mantle. It can be assumed that in this subduction zone the volume of oceanic crust, subducted into the mantle many millions of years ago, turned out to be sufficient for penetration into the liquid core, forming the complex shape restrictions for free circulation of the core liquid. As a result the vortex currents can be formed and effect on the geomagnetic field variations.
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INTERPRETATION OF MAGNETIC ANOMALIES IN CONDITIONS OF PRESENCE OF RESIDUAL MAGNETIZATION AND OTHER COMPLICATIONS
Konstantin M. Ermokhin
Pushkov institute of terrestrial magnetism, ionosphere and radio wave propagation of the Russian Academy of Sciences St.-Petersburg Filial (SPbF IZMIRAN), St.-Petersburg, Mendeleev line 1.
Traditionally, when interpreting the data of magnetic survey measurements it is assumed that all objects are magnetized on the modern field. All existing methods of solving the inverse problem are based on this assumption. This assumption is forced, because it is impossible to reliably determine the presence of residual magnetization a priori. In addition, the degree of ambiguity in the solution of the inverse problem is increased many times. At the same time, the theory of paleomagnetism is based on the study of the parameters of the residual magnetization of rocks and it is based on the theory of mobilism, prevailing in modern Geology. The assumption of a general magnetization in the modern field and the data of paleomagnetism are in direct contradiction requiring some sort of permission. It is also believed that at a depth of 20-30 km there is no magnetism, because the rocks are melted there. But at the transition point Curie iron, for example, as the second most common metal in the earth's crust, goes into a state of paramagnetic, rather than demagnetized at all. Moreover, according to the generalized Curie-Weiss formula: , where χ is the magnetic susceptibility, T is the (TCTTTT ) /( cc ) , temperature, Tc is the Curie point, C>0 and γ>0 are constant for each specific substance (rock). It turns out that at great depths there can be local moving areas with almost infinite χ (at ), creating large TT c magnetic anomalies on The earth's surface. There are experiments confirming this position, in particular for metals such as Ti, Zr, W, Mo. These circumstances reduce the degree of reliability of the results of traditional methods of interpretation of magnetic survey data. One of the possible ways to resolve the existing contradictions in the interpretation of magnetic data could be a method of analytical continuation of the magnetic field in the direction of sources. It allows to determine their depth, configuration and relative distribution of magnetization in section regardless of the direction of magnetization (which is not really known). This makes it possible to abandon any a priori assumptions about the objects of study and get a more adequate idea of the sources of magnetic anomalies.
MAGNETIC PROPERTIES OF SOILS FROM THE VOLGA-KAMA FOREST- STEPPE
L.A. Fattakhova, L.R. Kosareva, A.A. Shinkarev
Department of Geophysics and Geoinformation Technologies, Kazan Federal University, Kazan, Russia
We study the magnetic properties of virgin forest-steppe soils which formed on original vertical uniform unconsolidated parent material. In this work, profile samples of virgin dark-gray forest light loamy soil developed on a Permian (Kazanian stage) siltstone and virgin leached medium-thick fat light-loam 60 chernozem developed on the Quaternary deluvial loam were used. Both soils are characterized by accumulative type of magnetic susceptibility and its components. The accumulative type refers to a profile where the maximum accumulation of substances takes place at the surface with a gradual fall in their content with depth. The calculation of frequency-dependent magnetic susceptibility (F-factor) shows that in studied soils F-factor reflect changes in their ferromagnetic fraction. In the humus part of the soil profile magnetic materials are present predominantly as fine mineral particles, and their content in the <2.5 µm fraction decreases toward the soil-forming rock. Estimates of relative contributions of dia - / paramagnetic, superparamagnetic, and ferromagnetic components obtained from the coercive spectra shows that the increase in the magnetic susceptibility in organogenic horizons of forest-steppe soils is due to the contribution of the ferromagnetic component. The work is performed according to the Russian Government Program of Competitive Growth of Kazan Federal University.
TECTONIC AND GEOLOGICAL RESTRICTIONS ON DEVELOPING APWP FOR NORTH EURASIAN PLATE IN PERMIAN TIME
Fedyukin I.V.
The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences
Based on paleomagnetic data, analyzed possible scenarios of the relative position of the Siberian Platform and the European Platform ( during Permian time and drifting at the stage of consolidation in the structure of the supercontinent Pangea are considered. Modern paleomagnetic data allow for developing reliable APWP for Siberian and European platform. Comparison of the Siberian and European APWPs shows that since Mesozoic time the both platforms were part of the North Eurasian tectonic plate (North part of Pangea supercontinent). The plate was located in close to the modern coordinates and drifted with clockwise rotation. Since early Jurassic time, the eastern part of the Siberian platform reached the North Pole. During the Jurassic period, the rotation was maintained and by the end of the period the plate occupied a sublatitudinal position. For the Permian period (since early Permian time to P-T boundary), the relative position of the Siberian and European platforms can be described by the rotation of the Siberian block relative to the European block clockwise by 46° around the Euler pole, located in the area of the Northern Land (Severnaya Zemlya archipelago). Such a mechanism of interaction between Siberian and European platforms has determined the structural figure of deformations within the folded systems of the Arctic and Central Asian fold belt that have survived to the present day. Probably, the problem of space in the subconsolidated crust of Western Siberia, caused by the convergence of Siberian and European platforms, was realized through the constriction of the structures of the mobile belt to the north and south along the systems of shear zones. The research was supported by grant of the Government of the Russian Federation No. 14.Z50.31.0017.
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ANALOGUE OF THE NEDUBROVO ANOMALOUS REMANENCE IN THE ZHUKOV RAVINE SECTION, RUSSIAN BASIN: THE EVIDENCE FOR UNUSUAL BEHAVIOR OF GEOMAGNETIC FIELD BEFORE PERMIAN- TRIASSIC BOUNDARY
Fetisova A.M.1,2, Veselovskiy R.V.1,2, Mamontov D.A.1
1 – Geological department, Lomonosov Moscow State University, Moscow, Russia
2 – Schmidt Institute of Physics of the Earth RAS, Moscow, Russia
The Nedubrovo member of the Moscow sedimentary basin was firstly described by (Lozovsky et al., 2001) and still is the subject of continuing disputes due to the uncertainty of its age. Numerous determinations of fauna and flora allow to suggest the age of the Nedubrovo deposits as Upper Permian (Arefiev et al., 2016, Lozovsky et al., 2016) or Lower Triassic (Lozovsky et al., 2017). Any stratigraphic analogues of the Nedubrovo member have not been known. We present the results of complex paleomagnetic and rock magnetic studies of the upper Nedubrovo horizons, which are outcropped in the lower stream of the Kichmenga River, and compare them with the paleomagnetic data from Upper Permian red beds from the Zhukov Ravine outcrop (Gorokhovets settl.), which were re-studied by our team in 2018. The most important result is that we find the horizon with anomalous paleomagnetic direction in the Upper Permian layers of the Zhukov Ravine section, which paleomagnetic direction is consistent with anomalous one from the Nedubrovo outcrop, located 450 km to the NE. So, we have found additional evidence for the existence of a period of significant and prolonged deviation of the Earth's magnetic field configuration from the Geocentric Axial Dipole (GAD) in the latest Permian. The presence of anomalous paleomagnetic directions in the late Permian sedimentary and volcanic sections within Eurasia can be used as a powerful tool for local and regional magnetostratigraphic correlations, and also suggests the Upper Permian age of the Nedubrovo sediments. This work was funded by the grants #15-05-06843, 18-05-00593, 17-05-01121 (RFBR), #14.Z50.31.0017 (The Russian Government), MD1116.2018.5.
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RATE AND FREQUENCY OF EXTREME GEOMAGNETIC FIELD INTENSITY VARIATIONS
Yves Gallet1, Stanislava Yutsis-Akimova1,2, Alexandre Fournier1, Agnès Genevey3, Marie Troyano1, Phil Livermore4, Maxime Le Goff1, Michel Fortin5, Shahrmardan Amirov6
1 Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, UMR 7154 CNRS, F-75005 Paris, France
2 Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia
3 Sorbonne Universités, UPMC Univ. Paris 6, CNRS, UMR 8220, Laboratoire d’archéologie moléculaire et structurale (LAMS), Paris, France
4 School of Earth & Environment, University of Leeds, Leeds, UK
5 Faculté des lettres et des sciences humaines, Département des sciences historiques, Université Laval, Québec, Canada
6 Archeological Institute, Russian Academy of Sciences, Moscow, Russia
Rapid or extreme intensity variations in geomagnetic field are being attracted much interest within the archeomagnetism and geomagnetism communities. They are the subject of numerous archeomagnetic studies accompanied by the construction of archeo/geomagnetic field models. These studies follow the suggestion of geomagnetic "spikes" at the beginning of the first millennium BC proposed from archeointensity results obtained in the Near East. These events would be characterized by geomagnetic field intensity peaks over durations of only a few decades. They would imply variation rates of several μT per year, i.e. more than ten times the maximum rate of intensity variations known for the recent geomagnetic field. Such rates cannot be explained in the context of our current understanding of core dynamics, and their reliability is therefore a crucial issue for the geomagnetists. It seems likely that other episodes marked by strong intensity variation rates have occurred over the past millennia. With the aim to provide new constraints on both the amplitude and frequency of extreme geomagnetic variations, we recently carried out several studies dealing with the field intensity variations in the Middle East during the 6th and 3rd millennium BC. Our results show that these two periods were characterized by several short- lasting intensity peaks, but the associated variation rates (a few tenths of μT/year at most) remain much smaller than the values proposed for geomagnetic spikes. Our studies therefore do not allow one to confirm the reality of geomagnetic spikes. However, they highlight the fact that geomagnetic intensity peaks occurring on a time scale of the order of a century, associated with intensity variation rates of between ~ 0.05 μT/year and ~ 0.25 μT/an, constitute an essential element of the geomagnetic field secular variation.
63
THE UPPER CRETACEOUS PALEOMAGNETIC INVESTIGATION OF NORTHEAST OF WESTERN SIBERIA
Gnibidenko Z.N.1, Levicheva A.V.1, Semakov N.N.1, Marinov V.A.2
1 - Trofimuk Institute of Petroleum Geology and Geophysics, Novosibirsk,
2 - OOO “Tyumen Oil Scientific Centre”, Tyumen
Results of paleomagnetic investigations of the Upper Cretaceous sediments penetrated by three boreholes – Harampurskaya 106P, Novochaselka 5P and West-Chaselka 1P, stripped in the territory of the Ust’- Eniseisk region (the northeast of Krasnoyarsk Krai, West Siberia) are presented for the first time. The studied sediments are presented by Pokur, Kuznetsovo, Lowerchaselka, Upperchaselka and Tanama formations. All listed formations have the paleontological characteristic (foraminifera, molluscs) and its formed in the Cenomanian to Maastrichtian time interval. In total, 698 oriented cubic specimens for 230 stratigraphic levels were selected from the studied sediments. The component analysis of NRM has allowed to allocate characteristic remanent magnetization (ChRM). The studied sediments are characterized by normal and reverse polarity. For each borehole magnetostratigraphic sections have been constructed. Based on comparison and coordination of magnetostratigraphic sections of boreholes with each other the summary magnetostratigraphic section of the Upper Cretaceous of the Ust’-Eniseisk region covering stratigraphic units from the Cenomanian to Maastrichtian. This magnetostratigraphic section is compared with the world magnetochronological scale of Ogg [Ogg et al., 2016]. In Upperchaselka formation two magnetozones of the reversal polarity RK2m1 и RK2сp2 with one horizon of normal magnetization in the magnetozone RK2сp2 are allocated. These magnetozones are correlated with Chrons C31r and C32n.1r of this scale. Lowerchaselka, Kuznetsovo and Pokur formations have found normal polarity and make one long magnetozone of normal polarity NK2t-st2 compared with Chron C34 of normal polarity [Ogg et al., 2016].
PALEOMAGNETISM OF PALEOZOIC ROCKS OF THE EASTERN SLOPE OF THE SOUTH URALS
Golovanova I.V., Danukalov K.N., Kosarev A.M., Sal’manova R.Yu.
Institute of Geology - Subdivision of the Ufa Federal Research Centre of the Russian Academy of Sciences
Paleomagnetic studies in the Devonian and Carboniferous rocks of the South Urals can serve as an independent test of ideas about the collision of the Magnitogorsk island arc and the passive margin of the continent of Lavrussia. Here we present new paleomagnetic data on rocks of Devonian and Lower Carboniferous age of the western and central parts of the Magnitogorsk zone. These data allow us to compare coeval paleolatitudes of the Magnitogorsk island arc and the eastern edge of the East European continent and determine the mutual movement of two tectonic elements. The sections of Devonian and Lower Carboniferous volcanic and volcanic-sedimentary rocks in the Magnitogorsk zone of the South Urals were studied. Altogether more than 1500 oriented samples were tested and their stepwise thermal demagnetization was carried out. Interpretable results obtained for 15 Lower and Middle Devonian and 8 Lower Carboniferous sections. The high-temperature component of the magnetization, sometimes bipolar, is isolated in the samples of the basic effusives of most of the sections studied and in the jasper. This
64 remanence resides in magnetite and hematite and is likely primary as indicated by the fold test and reversal test both for the Devonian and the Lower Carboniferous samples. The results of paleomagnetic studies allow us to draw the following conclusions. The passive margin of the continent of Lavrusia and the nearby Magnitogorsk arc had a near-equatorial location. The position of the edge of the continent and the island arc was close to sublatitudinal. The calculated paleomagnetic pole for the Lower - Middle Devonian is quite close to the coeval pole of the paleocontinent Baltica (Laurussia), which indicates the probable position of the Magnitogorsk island arc the fairly close to the continent, but not in touch with it. Paleomagnetic data on rocks of the Lower Carboniferous age may indicate that in the Early Carboniferous the Magnitogorsk island arc experienced a turn, collided with the continent and formed a single whole with it. The research was performed under State Programme 0252-2017-0013.
PALEOMAGNETISM OF ORDOVICIAN-SILURIAN VOLCANIC ROCKS ON THE WESTERN SLOPE OF THE SOUTH URALS
Golovanova I.V., Danukalov K.N., Sergeeva N.D., Sal’manova R.Yu., Khatapov S.S.
Institute of Geology - Subdivision of the Ufa Federal Research Centre of the Russian Academy of Sciences
There are very few paleomagnetic data on the Ordovician and Silurian Periods both for the western slope of the Urals that is the deformed eastern margin of Baltica and the East European Platform as a whole. Reliable actual paleomagnetic data for the East European platform for the interval 458-432 Ma ago are absent. Meanwhile, the magnetic pole wanders considerably during this time. In recent years, U/Pb zircon dating of Paleozoic rocks has been obtained by studying the age of magmatites in the Bashkir Meganticlinorium previously assigned to the Precambrian. As a result, a Late Ordovician-Silurian magmatic complex has been established, all dating for which fit within a narrow interval of 435-455 Ma. The first results of the paleomagnetic study of one of the dated objects on the Ushat River showed good agreement with the calculated Baltica’s Apparent Polar Wander Paths (APWP) in the interval 437-442 Ma. Here we present new data on the study of Ordovician-Silurian volcanic rocks from four dated sections in the frame of the Taratash massif (a total of 16 flows). All these rocks are characterized by a strong magnetic signal. Permian remagnetization is almost absent in the samples under study. With the aid of stepwise thermal demagnetization, a high-temperature remanence was successfully isolated. This remanence resides in magnetite and hematite and is likely primary as indicated by the fold test. According to our calculations, the paleomagnetic pole has the coordinates 25.4° N and 199.7° E (25.4° S, 19.7° E), A95=6,1° showing a good agreement with calculated data on Baltica for 440 Ma. It was shown earlier that paleomagnetic results on Paleozoic rocks from the westernmost zones of the Ural fold belt reveal not local and regional rotation with respect to Baltica; hence the obtained result may be valid for the paleocontinent Baltica as a whole for time 437-442 Ma. We think that new data give a new Ordovician-Early Silurian paleomagnetic determination that can be used to refine the Early Paleozoic part of the Baltica’s APWP and for paleoreconstructions. This study was funded by grant 18-05-00631 from the Russian Foundation of Basic Research.
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LABORATORY MODELING OF THELLIER-COE PALEOINTENSITY DETERMINATIONS ON ROCKS BEARING TCRM
Gribov S.K.1, Shcherbakov V.P.1,2,3, Aphinogenova N.A.1, Smirnov M.A.1
1 - Geophysical Observatory “Borok” IPE RAS, Borok, Russia
2 - Kazan Federal University, Kazan, Russia
3 - IPE RAS, Moscow, Russia
One of the threats to obtain incorrect paleointensity (PI) data is the risk to misidentify NRM as TRM while in reality the studied rock carries CRM or TCRM. The danger is aggravating by the inability to distinguish CRM (TCRM) from TRM by any known means including the Thellier procedure. It was shown experimentally (Draeger et al., 2006; Gribov et al., 2017) that PI values determined from samples carrying laboratory induced CRM underestimate PI about 2 times. But equally important kind of chemical remanence, TCRM, created during slow cooling of igneous rocks due to oxidation of titanomagnetites was not investigate. Here we report results of such studies performed on laboratory. TCRM was created in a thermomagnetometer first by quick heating to 570 C following by slow cooling in air at rate of 1 C/hour in the presence of an external field of B = 50 μT. A complex magneto-mineralogical studies, comprising electron microscopy and X-ray diffractometry, have shown that creation of TCRM is associated with the formation of highly oxidized titanomaghemites and the magnetite due to their exsolution. Simulation of the Thellier method on these samples revealed that the application of this technique to samples carrying TCRM yields a magnetic field very closed to the true one giving the error of determination not more than 6 %. This result radically differs on that of obtained for the CRM and provides a good hope that contrary to the common fears, TCRM and TRM may be equivalent sources for true paleomagnetic information. The work was supported by the state assignment 0144-2014-00117 and the RFBR grant 17-05-00259.
PRELIMINARY COMPOSITE MAGNETOSTRATIGRAPHIC SECTION OF THE VALANZHINIAN OF THE CRIMEAN MOUNTAINS
Grishchenko V.A., Guzhikov A.Yu., Manikin A.G.
Saratov State University, Saratov
Within the works on the construction of the magnetostratigraphic scheme of the Valanginian in Mountain Crimea, there were analyzed the paleomagnetic and petromagnetic data on the oriented samples, taken from 363 stratigraphic levels of 10 sections in SW Crimea. The studied sediments of Valanginian constitute an unfavourable objects in paleomagnetic terms in view of several factors (landslide deformations, hypergene changes, presence of condensed slice and other factors). Anyway, the analysis and generalization of obtained materials let us conduct their magnetic-polar interpretation and propose the first layout of free magnetostratigraphic section of Valanginian in Mountain Crimea. The border interval of Berriasian-Valanginian is represented in the mountain Crimea by deep water clay facies. Unfortunately it is hardly deformed by landslides in the studied sections in the territory of Feodosia region (Zavodskaya balka, Sultanovka and mtn. Koklyuk). Anyway, magnetostratigraphic results are obtained, at least, in the Zavodskaya Balka section, where there were received the
66 paleomagnetic data on the underlying Berriasian sediments exposed by quarry. These materials are reliable and satisfy most part of criteria, including standard field tests that are required for the quality of similar data. By comparing the paleomagnetic column of Zavodskaya Balka section with Geologic Time Scale (2016), for the first time in the Eastern Crimea, it became possible to justify the level of the lower boundary of Valanginian in the area of reverse polarity magnetozone – analogue of M14r chron. In SW Crimea there were studied the sections of Lower Valanginian, represented mostly by shoaly littoral sandstones. Magnetostratigraphic data on the each of these sections individually may be reasonably doubted due to the numerous anomalous paleomagnetic directions and abundance of sedimentation breaks. However similar paleomagnetic structure is steady traced in 7 sections (mtn. Dlinnaya, mtn. Sheludivaya, mtn. Patil, mtn. Bolshoy Kermen, mtn. Selbuhra, mtn. Rezannaya), that gives much more trust to the received data. Magnetozones, established in the lower Valanginian of SW Crimea we presumably identify as analogues of M15-M12 chrons. Another key section of upper Valanginian is situated in SW Crimea near the mtn. Rezanaya (v. Verhorechye) that was earlier studied by O. Yampolskaya (2006). We’ve conducted the more detail sampling of this section and measured the samples using the cryogenic magnetometer 2G-Enterprices (IPE RAS, Moscow). New paleomagnetic data specify available definitions and raise their authenticity. In the paleomagnetic column as a result of complex analysis of bio-, magnetostratigraphic and isotope data we’ve established the analogues of chrons M12, M11A, M11, M10N. The research was financially supported by the RFBR (project № 18-35-00134 mol_a).
UPPER CRETACEOUS MAGNETOSTRATIGRAPHY OF LOWER VOLGA REGION
Guzhikova A.A., Guzhikov A.Yu., Manikin A.G., Grishchenko V.A.
Saratov State University, Saratov
In the Lower and Middle Volga region there are situated the key sections of Upper Cretaceous, which could decide many actual problems of stratigraphy if their paleomagnetic study would have been done. However, paleomagnetic properties of Upper Cretaceous sediments as in Volga region as on a whole Russian Plate were completely unstudied. One of the main causes of current situation is extremely low value of natural remanent magnetization of the carbonate rocks of Upper Cretaceous that is often lower than limit sensibility of measuring equipment. New high susceptible equipment including cryogenic magnetometers (SQUID) that became available at the present time made possible the appearance of new paleomagnetic data on Turonian-Maastrichtian of Saratov and Volgograd right bank of Volga, that satisfy most part of criteria, required for the quality of paleomagnetic materials. For example, according to the evaluation system, proposed by A.N. Khramov in the Supplements to the stratigraphic code of Russia (2000), their authenticity index is 7 (of possible 8). This estimation was given by such features like tying layer by layer of the samples to the sections, conducting magneto-mineralogical and component analysis, positive result of inversion test, forming composite paleomagnetic column on several overlapping sections and more. To date we have magnetostratigraphic data on the samples more than 500 different levels from 12 key sections of Turonian - Maastrichtian of Saratov and Volgograd right bank of Volga. The data on Campanian-Maastrihtian have a good agreement with traditional veiws about paleomagnetic structure of this stratigraphic interval in Geomagnetic Polarity Time Scale (GPTS). In the paleomagnetic zonality of Volga region sections there are identified the analogues of all the magnetic chrons, covering the interval of Campanian-Maastrichtian, except for late Maastrihtian short C30r and C29r, corresponding to the border interval of Cretaceous-Paleogene. On the results of integrated (bio-, magnetostratigraphic
67 and isotope) studies we managed to trace the lower border of Maastrichtian from GSSP, situated in SE of France, to the Russian Plate, specify the age of Campanian-Maastrichtian local stratigraphic units (formations) and show the diachroneity of their borders. In several sections of Turonian-Santonian of Volga region there was established a large reversal polarity magnetozone that contradicts with the data of GPTS. At the present time we could not find the convincing arguments in favor of remagnetization of rocks by aftersantonian geomagnetic field and, so, the hypothesis of the presence of longstanding epoch (epochs) of reversal polarity in Turonian-Santonian has the priority to existence.
ESTIMATION OF THE POSITION OF ARCH. NOVAYA ZEMLYA AT THE PERMIAN TIME ACCORDING TO PALEOMAGNETIC DATA
Iosifidi A. G.1,2
1- All-Russia Petroleum Research Exploration Institute (VNIGRI), St. Petersburg, 191014 Russia
2- Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation, St. Petersburg Branch, St. Petersburg, 191023 Russia
Reconstruction of ancient sedimentation basins by the paleomagnetic method is important, both for deciphering the history of their formation, and for the practice of prospecting for minerals. One of the promising areas for the search for minerals is the Barents-Kara region. From the north it is bounded by the Spitsbergen archipelago, the Franz Josef Land, the Severnay Zemya, and from the south by the Eastern European platform with the Pechora plate included in it and the Siberian plate. In the center of the region is the archipelago Novaya Zemlya. The existing paleomagnetic data for Paleozoic and Mesozoic deposits of the Novaya Zemlya archipelago are few and do not always meet modern reliability requirements. Nevertheless, according to the results of the first studies [Gurevich, Slautzitis, 1988], it was concluded that in the early Triassic the lithosphere block, which includes Novaya Zemlya and Franz Josef Land, located west of its present position with respect to the Russian platform and was rotate approximately 20 degrees counter-clockwise. In our work, we present new data on the Permian sediments of the southern island of the Novaya Zemlya archipelago from three sections (the Gusinaya Zemlya Peninsula and in the Rogachev-Taininsky District: the Severo Taynay River and the Margantsevyi Creek). The analysis of the data from the works [Gurevich, Slautzithis, 1984], [Abashev et al., 2017] and the new paleomagnetic determinations obtained is carried out. The Permian structures of the southern island of the Novaya Zemlya archipelago were laterally rotated clockwise by 28-34 degrees with respect to the Russian Platform.
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PALEOMAGNETIC STUDIES OF CARBONIFEROUS DEPOSITS OF THE RUSSIAN PLATFORM
Iosifidi A. G.1,2, Sergienko E. S.3, Salnaia N. V.4, Otmas N. M.1, Zuravlev A. V.5, Mikhailova V. A.1, Popov V. V.1,3, Danilova A. V.1
1- All-Russia Petroleum Research Exploration Institute (VNIGRI), St. Petersburg, 191014 Russia
2- Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation, St. Petersburg Branch, St. Petersburg, 191023 Russia
3- St. Petersburg State University, St. Petersburg, 199034 Russia
4- Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia
5- Institute of Geology, Komi Science Center, Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russia
Paleomagnetic studies of the Carboniferous deposits of the Russian Platform were started since the fifties of the last century. The quality of the available data does not always meet modern reliability criteria. In this paper, we present the results of paleomagnetic studies of the Carboniferous deposits of the Russian Platform, conducted in 2016-2018, which covers a time interval of 340 to 300 million years. During the stepwise thermal demagnetization four NRM components are isolated: component A (a present viscous component); the characteristic component C1 corresponding to the Carboniferous time, which in some cases correlates with the data of other researchers (a positive agreement test, class B); characteristic component P reflecting the Late Paleozoic remagnetization (mean Permian) and component C0, which indicates the presence of large particles or their aggregates in red clay. The main feature of the obtained data is the predominance of components of the natural remanent magnetization of the reverse polarity. Only in one section (Lyubytinsky district, Novgorod region) the bipolar component C1 is distinguished along the deposits of the Aleksin horizon of the Visean stage. The positions of the obtained paleomagnetic poles (component C1) show the movement of the Russian platform to the north with a clockwise rotation of 35 degrees and with a latitude offset of about 14 degrees. Comparison of the o o o average paleomagnetic pole of the component P (N = 7, Lat = 48 , Long = 156 , A95 = 3 ) with the one- o o o age component P2 (N / n = 28/51, Lat = 47 , Long = 168 , A95 = 4 ) on red clay from outcrops along the river Kamа allows estimating the possible shallow of the inclination of 6 degrees. The work was supported by the Russian Foundation for Basic Research under the project no. 16-05- 00603a.
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EXPLORING THE INFLUENCE OF THE GEOMAGNETIC POLARITY TIME SCALE ON RESULTS OF THE GEOCHRONOLOGICAL AND GEOHISTORICAL ANALYSIS OF THE MARINE MAGNETIC ANOMALIES
S. A. Ivanov1 and S. A. Merkuryev1,2
1 - Pushkov Institute of Terrestrial Magnetism of the Russian Academy of Sciences, St Petersburg Filial. 1 Mendeleevskaya Liniya, St Petersburg 199034, Russia
2 - Saint Petersburg State University, Institute of Earth Sciences, Universitetskaya nab.,7-9, St. Petersburg 199034, Russia [email protected] Since Vine and Matthews’ hypothesis, several tens of magnetic polarity time scales were constructed, according to the studies of marine magnetic anomalies (MMA). The appearance of new scales is usually associated with both the refinement of the scale structure and the use the methods of time scale calibration. On the basis of these scales, MMA have been identified in all the world's oceans, a digital age grid of the ocean floor was created [Muller et all, 2008], and the global digital MMA identification data set was incorporated into online downloadable repository [M. Seton et all, 2014]. From these MMA identifications the spreading regime of the ocean floor can be ascertained and a plate kinematic model calculated. Thus, for geochronological and kinematic interpretation of MMA the calculations use data of the geomagnetic field inversions, and therefore the results of these calculations depend on the used scales. We have conducted a study of how the choice of the scale affects the results of the geochronological and geohistorical interpretation of MMA in the northwestern part of the Indian Ocean. For the analysis, 15 most well-known Cenozoic scales were selected, starting with the time scale of Heitzler et al. (1968) and ending with the latest published scale of Gradstein et al. (2012). The study of the two periods of the scales was conducted for times of C1-C5 and C23-C26 chronos because they correspond to steady-state regime and the spreading rate was substantially did not change [Merkouriev, S., C. DeMets, 2006]. First, the identification of parts of the profile and segments of the given scale was carried out. For the given spreading rate, a model field was calculated and the correlation coefficient of the section of the observed profile and of various sections of the model profile was considered. Then this procedure was repeated for a model profile constructed with a different spreading rates. The correspondence between the section of the profile and the section of the scale was determined by the maximizations of the correlation coefficient both by the position of the section of the scale and by the spreading rate. The study revealed the following effects: 1. The age of identified anomalies, depending on the choice of scale, may differ by 10%, and for younger anomalies (chrones C1-C5), more modern scales give a more ancient age, and for older anomalies give a younger age what leads to the corresponding variations of the spreading rates. The spread of ages for ancient anomalies is greater than for the young ones. 2. It is shown that at the stage of identification of anomalies, the magnitude of the correlation coefficients depends on which scale was used in the simulation. In general, the use of more modern scales provides a higher correlation coefficient between observed and model profiles. However, the maximum correlation coefficients for ancient and young anomalies are not always achieved for the same scale. 3. The scatter of differential linear spreading rates over the last 10 million years, calculated on the basis of the kinematic rotation model of the Indian and Somali plates [Merkouriev, S., C. DeMets, 2006], is smaller when using scales with astronomical age calibration.
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THE AGGREGATION OF SUPERPARAMAGNETIC PARTICLES UNDER IN- PHASE AND ANTIPHASE OSCILLATIONS OF THEIR MAGNETIC MOMENTS
Karimov F.H.
Institute of earthquake engineering and seismology of the Academy of sciences of the Republic of Tajikistan
Two superparamagnetic particles interacting under in-phase and antiphase thermoactivated total magnetic moments oscillations are considered. In case of in-phase oscillations, both particles’ magnetic moments rotate in the same directions, while under antiphase oscillations in the opposite ones including in-plane and perpendicular plane of its polarizations. For simplicity, the particles are assumed to be spherical. The dipolar interaction energy is about equal to the magnetocrystalline anisotropy one for the magnetite particles at the normal physical conditions and so they both create principal energy barriers for the magnetic moments. At this ideal respect the shape and surface anisotropies don’t play a role in the aggregation. With antiphase oscillations of magnetic moments there is a permanent attraction between particles. With in-phase vibrations the repulsive forces turn up doing the particles move away from each other, when deflection angle of the magnetic moments of line, connecting the particles’ centers, ranges √3⁄ √3⁄ within the interval from arccos 3 up tо 휋 − arccos 3. Analysis of the standard equation for the movement of a particle under the dipole magnetic forces leads to the following conclusions: With in-phase oscillations of the magnetic moments of superparamagnetic particles the aggregation permanently breaks and restores along with time. The degree of aggregation is determining by means of 퐽2 nondimensional parameter 퐶 = ⁄ , where 푟 is a particle’s radius, 퐽 is particles’ magnetization, 휌 휌휔2푟2 is their substance density, 휔 is the circular frequency of magnetic moments’ oscillations. 퐶 is equal to 10 by the order of magnitude for the magnetite particles at 휔 = 109 Hz and 푟 = 10 nm. The run-away distance between disaggregated 10 nm particles doesn’t exceed about 0.05 푟 and is of the same order of magnitude for the 1 nm ones. For the frequency 108 Hz the tear off distance is longer. Tiny and light enough particles with weak enough magnetization aggregate and disaggregate almost strictly following the dipolar oscillations, but some heavy ones, due to the inertia, aggregate later. But in both cases the particles get aggregation state by the beginning of the next oscillation cycle; The probability for the realization of aggregated state with antiphase oscillations in superparamagnetic particles is higher than for in-phase one, because of higher dipolar magnetic interaction energy barrier in the last case; Due to the energy barrier rise caused by dipolar magnetic attraction the relevant superparamagnetic particles transform to stable quasi single domain ones and the probability for realization of aggregated state also became higher than for disaggregated one; At elevated temperatures, but below the Curie temperature, the oscillation frequency raises and according to the parameter 퐶 the aggregation probability falls down.
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ROCK-MAGNETIC AND GRAIN SIZE DATA ON THE QUATERNARY MULTI-LAYERED KEY SECTION TOLOGOY (BURYATIA, RUSSIA)
Kazansky A.Yu.1,2, Matasova G.G.3, Shchetnikov A. A.4, 5, 6, Filinov I. A.4,5,6
1- Geological Department of Lomonosov Moscow State University, Moscow, Russia
2- Geological Institute of Russian Academy of Sciences, Moscow, Russia
3- Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
4- Irkutsk State University, Irkutsk, Russia
5- Institute of the Earth’s Crust, Siberian Branch, Russian Academy of Sciences, Russia
6- Irkutsk Scientific Centre, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
The multi-layered key section Tologoy is located on the Selenga River left bank, 15 km southwest of Ulan-Ude city (51º45’ N, 107º29’ E), in the Western Trans-Baikal region. It holds a long record of Quaternary sedimentation since Early Pleistocene through Holocene. The section is composed of 20 m thick succession of silt, sandy silt and sand with fossil soil horizons. 200 samples for rock-magnetic and grain size analysis were taken each 10 cm over the section. Grain size results allowed to improve the field description of the section and to give its more detailed subdivision, particularly two additional fossil soils were recognized in the upper and lower parts of the section. Magnetic fraction of the sediments is closely connected with silt granulometric fraction. Correlation coefficients between silt fraction and concentration-sensitive rock-magnetic parameters exceed 0.55 in the upper part of the section and 0.7 in its lower part. It means that magnetic grains are mostly of terrigenous origin. Variations of rock-magnetic parameters over the section clearly reflect its structure in accordance with so called “Siberian mechanism”. Concentration-sensitive parameters (magnetic susceptibility, different types of magnetization) have low values in fossil soils and enhanced values in surrounding silt and sand. The fossil soils also contain more high coercivity minerals and superparamagnetic grains as well as paramagnetic material. Magnetic grain size in fossil soils is smaller, however in the fossil soils from the lower part of the section and proportion of SD grains in their assemblages is slightly higher than in the upper part, thus indicating more warm and humid climatic conditions. Anisotropy of magnetic susceptibility of the strata demonstrates a typical sedimentary texture; however, sedimentation here occurred on the slope inclined to the west. The main direction of paleotransport of sedimentary material was changing gradually in time from N-S to NE-SW. This work was supported by the Russian Foundation for Basic Research (project no. 18-05-00215, 16-05- 00586) and Ministry of education and science of the Russian Federation (project no. 2017-220-06-1656).
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MAGNETIC PROPERTIES OF BRICKS: SUPERPARAMAGNETISM AND PRESENCE OF HIGH-COERCIVITY-LOW-UNBLOCKING-TEMPERATURE MAGNETIC PHASE
P.V. Kharitonskii1, A. Kosterov2, I.M. Berestnev2, E.S. Sergienko2
1 Saint-Petersburg State Electrotechnical University “LETI”
2 Saint-Petersburg State University
Archaeological ceramics is the most important material from which the information on the geomagnetic field behavior during the last several millennia can be extracted. The magnetic mineralogy of bricks and ceramics in general is commonly considered as quite simple and straightforward, main magnetic phases being hematite and magnetite/maghemite. However, recently it was recognized [McIntosh et al., 2007, 2011] that a high-coercivity-low-unblocking-temperature (HCLT) magnetic phase is also present in many ceramic samples, identified tentatively as ε-Fe2O3 [López-Sanchez et al., 2017]. Towards this end, we investigated a small collection of bricks from different regions of European Russia, having ages from recent to mid-18th century. Magnetic measurements included room-temperature hysteresis loops and backfield curves, and thermomagnetic analysis at high and low temperatures. To specifically address the presence of ultrafine superparamagnetic particles, we measured the frequency- dependent initial magnetic susceptibility at room temperature, and, for selected samples, also as a function of temperature between 2 K and 300 K. Additionally, samples were analyzed using scanning electron microscopy and X-ray diffraction. According to the magnetic measurements, none of our samples contain stoichiometric magnetite though a phase with Curie temperatures in the 500-600°C is omnipresent. We infer it to be an oxidized magnetite/maghemite, possibly also cation-substituted. Curie temperatures which would correspond to hematite were not detected. At the same time, inflection points around 200°C characteristic of a HCLT phase [McIntosh et al., 2007, 2011] were observed in most samples. The presence of this phase is further supported by room-temperature hysteresis loops which (i) do not saturate in the highest available field (2 T) and (ii) yield rather strong high-field magnetization which would require an unfeasibly large amount of a hematite-like phase to explain it. Finally, in most samples we observe a strong frequency dependence of susceptibility extending from ~ 20 K to room temperature and possibly above. This study was partially supported by the RFBR grant No. 18-05-00626 and used the equipment of the resource centers of the Science Park of St. Petersburg State University: Geomodel, Centre for Diagnostics of Functional Materials for Medicine, Pharmacology and Nanoelectronics, and Centre for X-ray Diffraction Studies.
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PETROMAGNETIC LEGEND OF THE BASIS OF THE EASTERN BOARD OF THE TUNGUS SYNECLISE (WORKING OPTION)
Alexander A. Kirguev1, Konstantin M. Konstantinov1,2, Alexanderа E. Vasilyeva3
1Geological Enterprise of Exploration, Public Joint Stock Company «ALROSA» 678174, Yakutia, Sakha Republic, Mirny, Chernychevskoe St., 16, Russia
2Institute of the Earth’s Crust, Siberian Branch of RAS, 664033, Irkutsk, Lermontov St., 128, Russia
3Institute of the Diamond and Precious Metal Geology Institute, Siberian Branch of RAS, 677980, Yakutsk, Lenin St., 39, Russia
In the process of its formation, the basites of the Tungus syneclise, due to the physico-geological laws of formation, formed inside the bodies (sills, dikes, etc.) petromagnetic taxons (PMT), which are characterized by certain statistical values of density and magnetic parameters. According to the nature of their distribution, PMT are subdivided into petromagnetic groups (PMG) and petromagnetic heterogenetics (PMHs). In its turn, PMT is composed of petromagnetic complexes (PMC), corresponding to the magmatic phases of the introduction of basites. Three phases were distinguished in the scheme of development of trap magmatism of the eastern side of the Tunguska syneclise: 1 - intrusive γβP2, 2 - volcano-subvolcanic β0-γβP2-T1 and 3 - intrusive γβT1. PMT allow more securely zoning of the Yakut diamondiferous province closed by the trap areas in order to develop a methodology for prospecting for indigenous diamond deposits, as well as isolating structural and tubular types of anomalies over kimberlite pipes based on gravimagnetic exploration materials. On the basis of the geological legend, a petromagnetic legend was developed that makes it possible to classify the basalts of the eastern side of the Tunguska syneclise along the introduction phases with a high degree of probability. It is known that at the time of its formation, the traps of the first and second introduction phases were magnetized positively (sub-consistent with the current field), and the third phase-negatively. The most informative magnetic parameters that reflect changes in the conditions of crystallization of basites are magnetic susceptibility (æ), natural remanent magnetization (NRM) and Koenigsberger coefficient (factor Q). On their basis, PMG are well distinguished as the taxa of traps, the magnetic characteristics of which vary in space (differentiation, contamination, etc.) for homogeneous chemical, petrographic, etc. parameters. Depending on this, the amount of PMG can be infinite. PMHs is a PMT of traps, which magnetic characteristics vary in time. Nowadays, in Permo-Triassic basites are established four genetic types of PMHs: the first type was formed due to magnetization by the reversal geomagnetic field; The 2-nd type is due to the roasting of basites of early phase by introduction of a late Intrusive phase; the 3-rd type - as a result of the effect of self-reversal of titanomagnetites; 4th type - due to lightning strikes PMHs completely and easier explain the presence in the one or another phase of the basilitic magmatism of the eastern side of the Tunguska syneclise of vectors of the EOH opposite sign, than the previously advanced petromagnetic legends. The distribution of the current magnetization vectors of Permotrias traps of the eastern side of the Tunguska syneclise is subject to strict statistical regularities, by means of which their components (intensity and direction) can be calculated. The established regularities will allow to significantly improve the quality of physical and geological modeling of magnetic fields in the territories of IV and V geotypes.
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PETRO- AND PALEOMAGNETIC CHARACTERISTICS OF KIMBERLITES AND BASITES IN THE KYUTINGDE GRABEN (NORTHEASTERN SIBERIAN PLATFORM)
Innokentiy K. Konstantinov1, Konstantin M. Konstantinov1,2, Mikhail D. Tomshin3, Dimitri P. Gladkochub1, Andrey A. Jakovlev2, Alexandra E. Vasil’eva3
1Institute of the Earth’s Crust, Siberian Branch of RAS, 664033, Irkutsk, Lermontov St., 128, Russia
2Geological Enterprise of Exploration, Public Joint Stock Company «ALROSA» 678174, Yakutia, Sakha Republic, Mirny, Chernychevskoe St., 16, Russia
3Institute of the Diamond and Precious Metal Geology Institute, Siberian Branch of RAS, 677980, Yakutsk, Lenin St., 39, Russia
The present study of the Kyutingde graben rocks is a logical continuation of investigations of the geological structure and the development history of the northeastern Siberian platform (Gladkochub et al., 2009; Wingate et al., 2009; Konstantinov et al., 2012). Magmatic activity in the area was controlled by the NW-striking Molodo-Popigay fault zone, and had a repeated character. We have studied dolerite dikes and sills of the Molodo-Udzha (PZ2mu) and Molodo (P2-T1ml) intrusive complexes as well as Middle Mesozoic kimberlites of the Kuoika field (Velikan dike, Obnazhyonnaya and Ruslovaya pipes). The study revealed significant differences in petrophysical parameters of the basites of the Molodo-Udzha and Molodo intrusive complexes, kimberlites, and their host rocks. On the background of the host rocks, all these magmatites are manifested by positive magnetic anomalies of different amplitude and form. Paleomagnetic directions for the Devonian basites are divided into two clusters. One of them correlates well with the data obtained for the Appaya Formation (Frasnian, 385-375 Ma) while the other is characteristic of older times (470-460 Ma) and cannot be adequately explained in the context of epochs of tectonomagmatic activation. Vectors of the characteristic natural remanent magnetization (NRM) for the Permo-Triassic basites have positive polarity (N), those for the Obnazhyonnaya and Ruslovaya kimberlite pipes have negative polarity (R), and for the Velikan dike variable polarity (NR). It is obvious that formation of the studied kimberlites followed the emplacement of the Permo-Triassic basites, most likely in Late Triassic-Middle Jurassic times (250-160 Ma). References Gladkochub, D.P., Stanevich, A.M. et al., 2009. The Mesoproterozoic Udzha Paleorift (Northern Siberian Craton): New Data on Age of basites, Stratigraphy, and Microphytology. Doklady Earth Sciences, Vol. 425A, No.3, pp.371-377. Konstantinov, K.M., Tomshin, M.D. et al., 2012. Paleomagnetic and petrogeochemical characteristics of Early Mesozoic basites in the Udzha River basin (northeastern Siberian Platform). Lithosphere, No. 3, pp. 80-98 (in Russian). Wingate, M. N.D., Pisarevsky, S.A. et al., 2009. Geochronology and paleomagnetism of mafic igneous rocks in the Olenek Uplift, northern Siberia: Implications for Mesoproterozoic supercontinents and paleogeography. Precambrian Research 170, pp. 256-266.
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PALEOMAGNETIC CHARACTERISTICS OF DOLERITE DYKES OF THE VILUY-MARKHA FAULT ZONE (YAKUT DIAMONDIFEROUS PROVINCE)
Konstantin M. Konstantinov1,2, Shamil Z. Ibragimov3, Innokentiy K. Konstantinov2, Alexander A. Kirguev1, Mikhail D. Tomshin4,
1Geological Enterprise of Exploration, Public Joint Stock Company «ALROSA» 678174, Yakutia, Sakha Republic, Mirny, Chernychevskoe St., 16, Russia
2Institute of the Earth’s Crust, Siberian Branch of RAS, 664033, Irkutsk, Lermontov St., 128, Russia
3Institute of Geology and Petroleum Technologies, Kazan (Volga Region) Federal University, Kazan, 420111, Kremlyovskaya St. 4/5, Russia
4Institute of the Diamond and Precious Metal Geology Institute, Siberian Branch of RAS, 677980, Yakutsk, Lenin St., 39, Russia
On the operating fields of «ALROSA» (PJSC) Mir and Nyurbinskaya of the Yakut Diamondiferous Province (YDP) are carried out petro-and paleomagnetic studies of dolerites from the pre-kimberlite dykes of a Viluy-Markha intrusive complex. Basic distinctions of dolerites of two fields are observed on values of a magnetic susceptibility of æ, the natural remanent magnetization (NRM) and a factor of Q. For dolerites of the pit Nyurbinsky factor Q=1.31 - is considerably higher in comparison with other mafic intrusions of the middle Paleozoic Q<0.8 (Kravchinsky et al., 2002.). It can be considered as a petromagnetic marker of mapping the pre-kimberlite dykes as a part of the Viluy-Markha fault zone. Results of magnetic-mineralogical studies of dolerites demonstrate that their anisotropy of a magnetic susceptibility corresponds to morphology of bodies - to «dykes» type, the main mineral which is responsible for magnetization is titano-magnetite that is almost not oxidized (primary), and its domain structure treats pseudo-one-domain area of ferromagnetic particles. In the studied samples negative vectors of characteristic NRM which form two independent clusters in the first quarter of the stereogram are established. On each of them the paleomagnetic pole which is compared with the apparent polar wander path (APWP) of the Siberian platform is calculated. Paleomagnetic data show that the emplacement of Mirniy and Nyurba dyke complexes happened at different times: 380 Ma (late Devonian) and 420 Ma (late Silurian-early Devonian) consequently. Perhaps, they belong to two different dyke swarms. The younger corresponds to eruption of Appaya suite basalts (Frasnian, 375-385 million years) and well fit with an age of the kimberlites of Mir pipe which are breaking through a dyke (Famennian, 360-375 million years). Paleomagnetic date of older dyke swarm well coincides with poles the kimberlites of pipes Nyurbinskaya and Botuobinskaya that testifies to insignificant time difference of their emplacement. The obtained data confirm existence in the YDP two events of kimberlite eruption: late Silurian-early Devonian (S2-D1) and late Devonian-early Carboniferous (D3-C1). References Kravchinsky V.A., Konstantinov K.M. et al., 2002. Paleomagnetism of East Siberian traps and kimberlites: two new poles and paleogeographic reconstructions at about 360 and 250 Ma / Geophys. J. Int. № 48. pp. 1-33.
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PALEOMAGNETISM OF DOLERITE DIKES OF THE CHARA-SINSK FAULT ZONE (ALDAN BLOCK OF THE SIBERIAN PLATFORM)
Konstantin M. Konstantinov1,2, Innokentiy K. Konstantinov2, Shamil Z. Ibragimov3, Mikhail D. Tomshin4, Andrey A. Jakovlev1
1Geological Enterprise of Exploration, Public Joint Stock Company «ALROSA» 678174, Yakutia, Sakha Republic, Mirny, Chernychevskoe St. 16, Russia
2Institute of the Earth’s Crust, Siberian Branch of RAS, 664033, Irkutsk, Lermontov St., 128, Russia
3Institute of Geology and Petroleum Technologies, Kazan (Volga Region) Federal University, Kazan, 420111, Kremlyovskaya St. 4/5, Russia
4Institute of the Diamond and Precious Metal Geology Institute, Siberian Branch of RAS, 677980, Yakutsk, Lenin St., 39, Russia
Situated on the southern shoulder of the Vilyui paleorift system is an extensive dike belt controlled by the Chara-Sinsk fault zone (CSFZ). The latter extends northeasterly for 750 km, ranging in width from 50 km in the southwest to over 120 km in the northeast. Dike belts normally associate with the intrusive facies basites manifested as dikes, sills and chonoliths intruding into Cambrian, Ordovician and, less frequently, Silurian carbonate and argillo-carbonate deposits. The intrusions are characterized by weak intra-chamber differentiation. A particular body normally contains one rock variety most often represented by prismatic ophitic gabbro-dolerites. The dolerite dikes were studied in the bank exposures of the Lena River and its tributaries (Chara, Sinyaya, etc.). The age of the basites is estimated at 364-362 Ma. The dolerite and gabbro-dolerite composition of the older dikes change into sub-alkaline quartz gabbro-dolerites, monzonite porphyries, syenites, etc. in the younger dikes (Tomshin, 1990). Petromagnetic and magnetic-mineralogical data are available for all of the studied dikes. Most suitable for paleomagnetic studies were dolerites from the eastern side of the CSFZ. The laboratory demagnetization experiments on dolerites made it possible to determine directions of characteristic natural remanent magnetization (NRM) of which the nature can be interpreted as primary as shown by burning and reversal tests. For the studied dikes (N=7), a preliminary paleomagnetic pole is calculated, with the coordinates: latitude =15.6o, longitude =78.3o, and confidence interval dp/dm=9.1/13.2o. The pole is located to the west of the Middle Paleozoic poles, which supports the hypothesis of the clockwise rotation of the Aldan block with respect to the Anabar-Angara one as a result of opening of the Vilyui paleorift in the eastern Siberian platform (Pavlov et al., 2008; Tomshin, Konstantinov, 2005). References Tomshin, M.D., Koroleva, O.V., 1990. Composite dykes of the Vilyisk paleorift system, Siberian platform, Yakutia / Mafic dykes and emplacement mechanisms / Rotteerdam. Brockfield, pp. 535-540. Tomshin, M.D., Konstantinov, K.M., 2005. Basic dike belts of the Vilyui paleorift (Siberian platform) / Fifth International Dyke Conference IDC 5, Rovaniemi, Finland, p. 51. Pavlov, V., Bachtadse V., and Mikhailov, V., 2008. New Middle Cambrian and Middle Ordovician palaeomagnetic data from Siberia: Llandelian magnetostratigraphy and relative rotation between the Aldan and Anabar-Angara blocks // Earth and Planetary Science Letters, V. 276 (3-4), p. 229-242.
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THE MAGNETIC PROPERTIES OF LAKE TURGOYAK SEDIMENTS (CHELYABINSK REGION, RUSSIA)
L. Kosareva 1, D. Nurgaliev 1, P. Krylov 1, D. Kuzina 1, V. Antonenko 1, A. Yusupova 1, V. Vorob’ev 2, V. Evtygin 2
1 – Institute of Geology and Petroleum Technologies, Kazan Federal University, Russia
2 – Interdisciplinary center for analytical microscopy, Kazan Federal University, Russia
In this work we perform results of magneto-mineralogical investigations of Lake Turgoyak sediments (Chelyabinsk Oblast, Russia (55°09′N, 60°04′E)). Before sampling on the lake were conducted seismoacoustic investigations for studying the sediments stratification. Total 5 cores with the lenght between 4 to 6 meters were obtained. The magnetic susceptibility, NRM, hysteresis parameters and induced magnetization versus temperature, TEM and SEM microscopy were carried out to determine samples magnetic mineralogy. C14 dating was made for 10 samples. NRM values vary within 0.134 – 4.05·mA/m, magnetic susceptibility 0.35 – 18.3510-5 SI. According thermomagnetic diagrams sediments can be devided into 4 groups by depth: 0 – 1,42 m, 1,44 – 2,80 m, 2,82 – 3,80 m, 3.82 – 5,40 m. The Day-Dunlop diagram obtained from hysteresis parameters allows one to draw conclusions about the presence in the sediments of a mixture of MD, SD (probably of biogenic origin), PSD and possibly very fine SP particles. On the basis of petromagnetic properties of sediments made conclusions of different stages of sedimentation in lake and changes in paleoclimate of this region during Holocene and Upper Pleistocene. This work was funded by the subsidy № 5.3174.2017/4.6 allocated to Kazan Federal University for the state assignment in the sphere of scientific activities and RFBR according to the research project № 17- 05-01246.
HIGH-FIELD HYSTERESIS AND LOW-TEMPERATURE MAGNETIC PROPERTIES OF HEMATITE- AND GOETHITE-BEARING SEDIMENTS
A. Kosterov1, E. Sergienko1, A. Iosifidi2,3, S. Yanson1
1Saint-Petersburg State University
2 All-Russia Petroleum Research Exploration Institute (VNIGRI)
3 Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation, St. Petersburg Branch [email protected]
Continental sedimentary rocks and particularly red beds often contain magnetically hard mineral phases such as hematite and goethite. In this case, magnetic hysteresis loops measured in moderate (< 2 T) fields can serve but a qualitative criterion for the presence of these minerals. We therefore measured room temperature hysteresis loops in a 7 T field and DC backfield demagnetization curves in fields up to 3 T using a MPMS 3 instrument. These were complemented by thermomagnetic analysis at low and high temperatures, microscopic observations, and X-ray diffraction study. Sediments from different regions of the East European platform, mostly of Carboniferous age were used for this study.
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High-field magnetic hysteresis loops alone appear not sufficient to definitely discriminate goethite from hematite, though there is, expectedly, a tendency that increasing goethite content leads to magnetic hardening, sometimes to the extreme, coercive force reaching 1 T and coercivity of remanence 1.7 T. At the same time, combining these with the low-temperature magnetic measurements provides a better insight into the magnetic mineralogy of sediments. Still, acquiring the reference data on well characterized goethite and hematite samples is highly desirable. This research has been partly supported by RFBR, grant No. 16-05-00603.
PALEOMAGNETISM OF PHANEROZOIC GEOLOGICAL COMPLEXES OF MONGOLIA AND TUVA
D.V. Kovalenko
Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry RAS (IGEM RAS)
Analysis of the pre-folded close to the primary magnetization showed: 1. The Caledonian block moved independently of the Siberian craton from Ordovician to Devonian, and was located to the North of the Siberian continent (Fig.1). 2. In Devon there was a tectonic combination of the Caledonian block and Siberia (Fig.1). This event was associated deformation rocks, granitoid and mantle magmatism. 3. The Caledonian block's strata rotated in a horizontal plane relative to Siberia, possibly due to the transpressive type of collision. 4. In the late Carboniferous-Permian paleolatitudes Caledonian block significantly different from the Siberian paleolatitudes. Perhaps this difference is due to the formation of the Mongolian-Okhotsk ocean. Analysis post-folded magnetization showed: 1. In early Phanerozoic rocks of Mongolia and Tuva are allocated to the secondary component of magnetization of normal and reverse polarity. 2. Components of the magnetization of the normal polarity associated with the Mesozoic remagnetization. Components of reverse polarity, apparently, was formed in late Carboniferous-Permian in the period superchron reverse polarity. 3. The analysis of the distribution of the reverse polarity magnetization components in the Mongolian structure allows for zoning. The regions of Mongolia with minor post-Permian deformations of the rocks, with complex post-Permian deformations and large blocks rotated around the horizontal axis are distinguished (Kovalenko, 2017). References Kovalenko D. V. Chernov, E. E. Paleomagnetism of the Carboniferous-Permian magmatic complexes of the southern part of Mongolia. Physics of The Earth. 2008, No. 5, p. 81-96 Kovalenko D. V. Paleomagnetism of early Paleozoic geological complexes of Mongolia. Physics of the Earth. 2017. No. 3. p. 88-106. Pavlov, V. E., Paleomagnetism of the Siberian platform. Abstract on competition of a scientific degree doctor of physics and mathematics sciences. Moscow. 2015. Bachtadse V., Pavlov V.E., Kazansky A.Y. et al. Siluro-Devonian paleomagnetic results from the Tuva Terrane (southern Siberia, Russia)' implications for the paleogeography of Siberia // J. Geophys. Res. 2000. 105 (B6). P. 13,509-13,518
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Besse, J., Courtillot, V., 2002. Apparent and true polar wander and the geometry of the geomagnetic field over the last 200 Myr. J. Geophys. Res. 107 (B11), 6–31. Van Hinsbergen D., Straathof G.B., Kuiper K.F., Cunningham W.D., Wijbrans J. No vertical axis rotation during neogen transpressional orogeny in the NE Goby Altai: coinciding Mongolian and Eurasian early cretaceous apparent polar paths // Geophys. J. Int., 2008, N173, p.105-126.
Fig.1. Paleolatitudes calculated from the paleomagnetic poles of Siberia (1) (Pavlov, 2016; Besse and Courtillot, 2003) and the Caledonian Central Asia block (2) (Kovalenko, 2017; Kovalenko, in print; Bachtadse et al., 2000; Kovalenko, Chernov, 2008; Van Hinsbergen, 2008).
RHYTHMS OF THE PALEOINTENSITY CHANGES WITH CHARACTERISTIC TIMES 5 AND 1 MA
A.Yu. Kurazhkovskii, N.A.Kurazhkovskaya, B.I.Klain
Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth, Russian Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia
[email protected]; [email protected]; [email protected]
Significant gaps in the information on variations in the geomagnetic field intensity exist. For example, until recently there were no paleomagnetic data, which allowed us to study variations of the paleointensity with characteristic times of 1‒10 million years. We have carried out a generalization of the fragmentary data of the Jurassic - Paleogene paleointensity obtained by the sedimentary rocks of the Russian plate and adjacent territories. As a result, curve of the behavior of the geomagnetic field intensity at the Jurassic - Paleogene interval (167-20 Ma) was obtained. Spectral analysis of this curve made it possible to distinguish variations in the paleointensity with characteristic times of 5 and 1 Ma. Comparison of the paleointensity variations with cycles of changes of the global sea level (cycles of transgression ‒ regression or T‒R cycles) showed that these processes are interrelated. The T‒R cycles data are taken from the Geologic Time Scale 2008. The paleointensity variations and changes of the 80 global sea level with the same characteristic times occurred. In addition, a correlation relationship between these processes was found. The increase in the amplitude of the paleointensity variations was mainly due to the regressions of the global sea. Thus, the detected form of the connection between such non-periodic processes as T‒R cycles and the paleointensity variations testifies that they are a reflection of a single planetary process.
RESULTS OF MAGNETIC AND PALEOMAGNETIC INVESTIGATIONS OF BABYI KAMEN’ SECTION, KEMEROVO REGION
D. Kuzina1, I. Gilmetdinov1, R. Aupov1, Yu. Balabanov1, L. Kosareva1, S. Zorina1, V. Silantiev1, V. Davydov1, 2
1 – Institute of Geology and Petroleum Technologies, Kazan Federal University, Russia
2 – Permian Research Institute, Boise State University, USA.
In paper described investigations of the reference Permian-Triassic succession exposed in the Babyi Kamen’ section in the left bank of the Tom’ River, Kemerovo region, Russia (54°23.079’N, 087°32.105’E). The samples collected within the Permian – Triassic transition. The thickness of investigated interval is about 197 meters, we collected 77 oriented samples. Magnetic susceptibility, hysteresis parameters, NRM measurements are carried out to determine changes in magnetic mineralogy and sedimentation settings (or environments). For studying mineralogy were used thermomagnetic analysis and petrographic analysis. It is shown that magnetite and hematite are the main carriers of magnetization in the studied rocks. The pyrite content in the samples is very low according to petrographic analyses and mapping Fe and S in the polished sections. Thermomagnetic demagnetization have been made for all collection and have been measured with a Cryogenic (SQUID) magnetometer 2G Enterprises (USA) located in a nonmagnetic room in the Laboratory of the Main Geomagnetic Field and Petromagnetism of the IPE RAS, Moscow. Some samples heated up to 680 °C depending on magnetization loss. Changes in polarity of magnetic field are also detected. Along the succession magnetic pole changes several times. According to magneto-mineralogical and lithological data some of the changes detected in the lower part of the section depend on environmental conditions of sedimentation. This work was funded by the subsidy № 5.2192.2017/4.6 allocated to Kazan Federal University for the state assignment in the sphere of scientific activities.
EARTH’s CRATER MAGNETIC ANOMALIES: NUMERICAL MODELING OF SIMPLE CRATERS
M. Yu. Kuzmicheva
Institute of Geospheres Dynamics RAS
Numerical simulations are quite successful reproducing the crater morphology, but it was not yet widely possible to model the crater negative anomaly. 81
As known a crater-forming impact alters the magnetization of the crust by way of excavation and mixing of target material, by thermal demagnetization (and following re-magnetization if possible), by shock demagnetization [1,2]. Heated in the impact, magnetic minerals in the crust cool below their Curie temperatures and acquire a thermo-remnant magnetization (TRM) with a magnitude proportional to the strength of the ambient magnetic field. Magnetic materials can be magnetized in an external magnetic field through shock remnant magnetization (SRM). Existing magnetization can be reduced or erased if the minerals are shocked in an ambient field too weak to induce a sufficient SRM. Post-impact hydrothermal system can lead to further TRM and/or the acquisition of chemical remnant magnetization (CRM). Generally, craters are characterized by circular magnetic low and short-wavelength intense anomalies produced by impact melt sheets and/or suevite deposits. Transient and final crater diameter dimensions are critical for estimations of energy released in impacts. Magnetic survey data show that disruption cavity size can be inferred from magnetic anomaly character [3]. Due to plate tectonics the present geomagnetic field at the crater location differs of this one at epoch when the primary crust was created, as well as of the field of the impact time. These differences exhibit in twist of cavity and melt dipoles. In presented work three-dimensional magnetostatic calculations of crustal magnetic field of simple craters have been performed. Magnetic properties of rocks in simulations were determined according [4]. After-impact magnetic anomalies associated with a magnetic cavity, with a melt sheet have been simulated, a relation of a magnetic low and crater transient diameter was determined. References: 1. Artemieva N. et al. (2005) GRL, 32, L222041 .2. Ugalde H. A. et al. (2005) Geological Society of America Special Papers, 384, p. 25-42. 3. Pilkington M. and Grieve R. (1992) Reviews of Geophysics, 30, p. 161-181. 4. Plado J. et al. (1999). Geological Society of America. Special paper 339: p. 229-239.
ANISOTROPY OF MAGNETIC SUSCEPTIBILITY IN THE PERMIAN- TRIASSIC INTRUSIONS FROM THE NORTHWESTERN SIBERIAN PLATFORM: IMPLICATIONS FOR THE MAGMA TRANSPORT PATTERNS
Latyshev A.V.1,2, Ulyahina P.S.2, Krivolutskaya N.A.3
1 – Lomonosov Moscow State University, Geological Faculty
2 – Schmidt Institute of the Physics of the Earth, Moscow
3 – Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow
The Siberian Traps LIP is considered to be the most voluminous region of intraplate magmatic activity in Phanerozoic. Despite the continuous investigation, the detailed reconstructions of the magma transport patterns during the Siberian Traps emplacement are scarce. According to the most popular model, the plume head was located beneath the northwestern Siberian platform, in the Norilsk region. Recent studies show that the lateral magma transport via the system of large and extent shallow sills was the important feature of magmatic activity. In our previous work, we obtained the similar pattern based on the detailed study of the anisotropy of magnetic susceptibility (AMS) in large sills of the Angara-Taseeva basin. Here we present the results of the detailed investigation of AMS in the intrusions from the Norilsk and Kulumbe districts (northwestern Siberian platform). These areas are located near the supposed center of 82
LIP and inherit the Precambrian Norilsk-Igarka paleorift zone. For the reconstruction of the magma flow direction we used the intrusions with the N-type of magnetic fabric, when the minimal axis K3 of AMS ellipsoid is orthogonal to the intrusion contact. In this case, the lineation of the maximal axis K1 was interpreted as the magma flow direction. The NW–SE magnetic lineation is the most common both in Norilsk and Kulumbe sill-like intrusions. Thus, magnetic lineation is almost normal to the regional fault zones of the NE strike, namely Norilsk-Kharaelakh and Imangda-Letninskiy faults. We suggest that during the Siberian Traps emplacement magma ascended through the weakened zones, and moved laterally from them in the shallow crust levels. Our scheme is consistent with the widespread idea about the magma-feeding role of the Norilsk-Kharaelakh fault. Thus, this pattern of magma flow transport controlled by the long-lived faults system is quite different from the fan-like distribution of thick sills dominating the magma flow in the Angara-Taseeva basin. This work was funded by RFBR projects 16-35-60114, 17-05-01121, 18-05-70094.
PALEOPROTEROZOIC TRENDS OF REMAGNETIZATION FOR THE KARELIAN CRATON: MYTH OR REALITY
Lubnina N.V., Tarasov N.A., Zakharov V.S.
M.V. Lomonosov Moscow State University, Faculty of Geology
Traditionally, during more than 20th-year paleomagnetic studies of Archean and Early Paleoproterozoic complexes of the Karelian craton (Fennoscandia), the stable component of the northwestern directions with moderate-steep downward inclinations is observed in the mid- and sometimes in the high temperature/coercivity intervals. It is commonly referred to as 'the Svecofennian remagnetization’ or overprint and dated as ~1.8 Ga. At the same time, in different parts of the Karelian craton, mean directions of these secondary components vary from each other and are dispersed, forming regular trends. These trends correlates within the accretion Svecofennian or collisional Lapland-Kola orogens, and also the Belomorian mobile belt. Usually they dated as 1.80–1.70 Ga, 1.95–1.90 Ga and 1.95–1.85 Ga respectively. However, in the border areas of these orogens clearly identify the trend of remagnetization is not always possible. Another important aspect of the research is to establish a correlation between remagnetization processes and composition of the rocks. Probably varies of early and late secondary components is caused not only with protolithic composition but also with different transformations of the rocks including whose fluid saturation and fracturing. In other words, natural trends are not a consistent rejuvenation / ancientness of the remagnetization within a whole orogen associated with the orientation of collision or accretion, but only the result of uneven changes (remagnetization) of different composition rocks. Moreover, for the Karelian craton, the position of different age Precambrian paleomagnetic poles often coincides with each other or with the poles of Precambrian or Phanerozoic remagnetization several times. At that, for all these poles, the primary origin of the high-temperature components is proved based on the positive paleomagnetic reliability tests (mainly contact test). It is planned to discuss whether such coincidences are evidence of the stable position of the Karelian craton in a particular part of the globe, or whether there is a result of a one-time Phanerozoic (?) remagnetization that is not reflected in paleomagnetic reliability tests. This is a contribution to the project RSF 18-05-00170.
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KEY EARLY PALEOPROTEOROZOIC 2.45 GA PALEOMAGNETIC POLE FOR THE KARELIAN CRATON: FURTHER PALEOMAGNETIC EVIDENCE
Lubnina N.V., Tarasov N.A.
M.V. Lomonosov Moscow State University, Faculty of Geology
We present a new paleomagnetic data from the Early Paleoproterozoic layered gabbronorite intrusions and mafic dykes and Archean host rocks within two terranes of the Karelian Craton, eastern Fennoscandian Shield. Early Paleorproterozoic Burakovka and Kivakka layered gabbronorite intrusions have been collected at Vodlozero and Central Karelian terranes respectively. Three groups of dykes have been collected within Pyaozero area of Central Karelian terrane: NEtrending ca. 2.45 Ga gabbronorite and diorite dykes, NW-trending ca. 2.4 Ga dolerite dykes (Stepanova et al. 2014). We also sampled Sariolian (ca 2.3 Ga) conglomerates containing pebbles both Early Paleozoic gabbronorites and NeoArchean granites at Vodlozero terrane. All studied samples from the Early Paleoprotrozoic layered intrusions and mafic dykes carried two stable components. Most typical is component of intermediate down to the NNW, corresponds to the Svecofennian remagnetisation (Mertanen et al. 1999). Component of SE intermediate down direction yielding a paleomagnetic pole 2.45 Ga based on a positive baked contact test is interpreted to represent the primary magnetization. In the Sariolian conglomerates two remanence components were isolated in both in the gabbronorite and granite pebbles. Stable mid-temperature components were removed in fields up to 20-40mT, and in temperatures up to 540°C, after which scattered component were disclosed in high fields/temperatures. Mid temperature component demonstrate northwestern directions with moderate downward inclinations, close to the mid-temperature/coercivity components in mafic dykes and correspond to the Svecofennian age remagnetization (negative conglomerate test). The high-temperature component isolated in both gabbronorites and granites has a chaotic distribution on the sphere. The high-temperature/coercivity component isolated in both gabbronorites and granites has a chaotic distribution on the sphere (positive conglomerate test). This only shows the partial remagnetization of rocks in Svecofennian time (ca 1.8 Ga), while the high temperature component has a primary origin. We propose a new Early Paleoproterozoic paleogeography at 2.45 Ga for the Karelia and Superior craton. This is a contribution to projects RFBR 17-05-01270.
EXPERIMENTAL MODELING OF CHEMICAL MAGNETIZATION IN OCEANIC BASALTS AND ITS PROPERTIES
Maksimochkin V.I., Grachev R.A., Tselebrovskiy A.N.
Lomonosov Moscow State University, the Faculty of Physics
During chemical transformations of minerals in the Earth's magnetic field, chemical remanent magnetization (CRM) can be formed, which interferes with the solution of paleomagnetic problems. The study of the properties of an artificially created CRM shows that there are conflicting data on the separation of CRM and TRM in rocks [Maksimochkin et al., 2015; Gribov et al., 2017]. To develop criteria for the recognition of CRM in NRM, an experimental simulation of CRM on the basalts samples of the Red Sea P72-2 and P72-4 and the study of its properties were carried out. 84
According to electron microscopy and thermomagnetic analysis, the magnetic mineral of these basalts is titanomagnetite with a magnetite consentration of 44.7% and 50.1% and Curie temperatures Tc=222±5°C and 258±10°C, respectively. The grains of the titanomagnetite of the dendritic structure in the initial state are homogeneous, the composition is close to the stoichiometric, the domain structure according to [Day et al., 1977] corresponds to the pseudo-single-domain state. Studies of samples annealed at temperatures Tan=290–535°C for 10 hours made it possible to distinguish two processes of transformation of the initial titanomagnetite. The first process was observed at annealing temperatures of 290–410 °C. It was characterized by an increase in the magnetic susceptibility and saturation magnetization by 1.5–1.6 times, an increase by 13–14% of the remanent saturation magnetization and a 10–15 % decrease in the magnetic stiffness, and also the inhomogeneity phase state, which was probably due to the heterogeneity of the oxidation of grains of different sizes. Annealing of the samples at 350 °C showed that saturation magnetization reached a maximum value after holding for 40.5 hours. With increasing dwell time the contribution to the saturation magnetization of the magnetic phase with a lower Curie temperature decreases. After annealing for t=40.5–110 hours, the thermomagnetic analysis showed the presence of one magnetic phase with Tc=490–510 °C. A distinctive feature of this process of transformation of titanomagnetite is its reversibility: heating of samples in an argon medium up to 600 °C led to homogenization of oxidized titanomagnetite. It is shown that an increase of the annealing temperature to T=460–535 °C, as well as an increase of annealing time up to 350 hours at T=350 °C, leads to changes in the magnetic properties of titanomagnetite, characteristic of oxy-decomposition. The restoration of the initial state of titanomagnetite after heating the samples to 600 °C in argon was not carried out in this case. It was found that CRM, measured at room temperature, increases with the annealing time by a law close to exponential, and reaches saturation at t=40 hours. The ratio of the partial thermoremanent magnetization (PTRM) formed in the temperature range from Tc to the annealing temperature decreases from 1.3–1.4 for t=4.5 hours to 0.93 for t=110 hours. Studies have shown that the properties of CRM and PTRM (Tc–Tan) approach each other with increasing oxidation state. With a high degree of oxidation of titanomagnetite, CRM can be identified as TRM. An indicator that the NRM in basalts in this case is CRM can be a significant decrease in the Curie temperature of the samples after heating them in an argon medium to 600 °C. In the middle stage of single-phase oxidation, the chemical and PTRM at T>Tan have practically identical spectra of blocking temperatures and differ significantly at T DETERMINATION OF PALEOINTENSITY OF GEOMAGNETIC FIELD ON THE VOLCANOES LAVAS OF KAMCHATKA V.I. Maksimochkin1), Yu.V. Sleptsova1), A.N. Nekrasov2) 1-Faculty of Physics Lomonosov Moscow State University 2-Institute of Experimental Mineralogy RAS [email protected], [email protected] Five samples of lavas of volcanoes of Kamchatka were investigated: 3 samples from the Avachinsky volcano and 1 sample from the Gorely volcano - no more than 8000 years old, 1 - from the lava flow of the Tolbachik volcano eruption in 2012. Thermomagnetic analysis carried out on the dependence of the magnetization in the field of 0.24T and the initial magnetic susceptibility on temperature showed that the titaniferous magnetite with the Curie temperature Tc=540÷580°C is the mineral responsible for the magnetic properties of the Avachinsky 85 volcano samples. The investigation of the grains of ore minerals in electron and magnetic-force microscopes revealed the presence of signs of high-temperature oxidation of titanomagnetite. The Curie temperature of the samples from Gorely and Tolbachik volcanoes was Tc=250-310°C. The paleointensity value Hdr=56µT, determined from the NRM of sample from the Tolbachik volcano using the Telier-Coe procedures, was quite close to the value of the modern magnetic field in the region of this volcano (НIGRF=53µT) according to the IGRF-12 model. It demonstrates the reliability of the methodology we used to determine the paleointensity from the remanent magnetization of igneous rocks. Age of the lava flow from the volcano Avachinsky was not known. The paleointensity values Hdr=50±4, 55±4, 58±6, determined from the samples from this volcano, were also quite close to the current value of НIGRF =52µT for the location of this volcano. It is concluded that the age of the investigated lava flow does not exceed 200 years. For the sample from the Gorely volcano, the value Hdr=69±6µT and the calculated value of VADM=10±0.9*1022А*m2 indicate that the investigated rock refers to the outpouring of lava that occurred 3-4 thousand years ago, which is in good agreement with the literature data on paleosecular variations of the geomagnetic field. The sample from Tolbachik volcano was not oriented. Investigating two samples from the Avachinsky volcano we managed to obtain quite close values of the coordinates of the paleomagnetic pole 67N 142E and 77N 133E. The limited data obtained did not allow to make a more unambiguous conclusion about the coordinates of the paleomagnetic pole. The measured values of declination and inclination of the remanent magnetization of one of the Avachinsky volcano samples indicate that the NRM was formed when the lava flow moved. INTERRELATIONS BETWEEN THE GRANULOMETRIC COMPOSITION, MAGNETIC PROPERTIES AND GEOCHEMICAL INDICATORS IN THE SUBAERIAL DEPOSITS OF THE ARCHAEOLOGICAL SITE "TUYANA" (TUNKA DEPRESSION, BAIKAL REGION, RUSSIA) Matasova G.G.1, Shchetnikov A. A.2,3,4, Kazansky A.Yu.5,6, Filinov I. A.2,3,4 1- Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia 2- Irkutsk State University, Irkutsk, Russia 3- Institute of the Earth’s Crust, Siberian Branch, Russian Academy of Sciences, Russia 4- Irkutsk Scientific Centre, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia 5- Geological Department of Lomonosov Moscow State University, Moscow, Russia 6- Geological Institute of Russian Academy of Sciences, Moscow, Russia The Tuyana section (51º42'N, 102º41'E) is located at foothills of Khamar Daban ridge, on the right bank of the Irkut river. A unique multi-layer archaeological site of the Upper Paleolithic age was discovered here in 2011. We present the analysis of correlation between granulometric composition, content of oxides of various elements, geochemical indicators of climate and rock-magnetic characteristics. The granulometric, chemical composition and rock-magnetic properties of sedimentary rocks are influenced by the same factors: the chemical composition and genesis of rocks in the source, the type and 86 degree of weathering, the distance and the mode of transport, the post-sedimentation processes of reworking of material in the sedimentation environment. Those transformations are resulted from different climatic and physicochemical conditions of sedimentation. In general, sand fractions on the one hand, are correlated with concentration-dependent magnetic characteristics, on the other hand, with SiO2, Na2O, and in the lower part of the section, are additionally correlated with MgO and K2O. The content of coarse silt fraction is almost constant all over the section, but in its upper part it is connected with Na2O and CaO, while in the lower part with SiO2, MgO and K2O. A small amount of magnetically hard minerals was recognized in the coarse silt fraction. Fine silt fraction is closely related to Fe2O3 and PPP all over the section. In the upper part of the section the fine silt fraction correlates with Al2O3 and Corg, in the middle part - with MgO, P2O5 and K2O and in the lower part - with CaO, TiO2, MnO and Corg. The highest content of paramagnetic minerals contributing up to 33% to the total magnetism of the deposits is connected with silt fraction. Fine-grained fractions, clay and mud, are correlated with LOI and Corg throughout the section, and additionally with Al2O3 and with P2O5, K2O, CaO, TiO2 and MnO in the upper and middle. Fine-grained fractions contain OD and SPM magnetic grains of authigenic origin. Climatic petrochemical indexes differently correlate with granulometric fractions and magnetic characteristics, depending on the constituent oxides. The closest correlations with rock-magnetic parameters demonstrate the following petrochemical modules: AM, NM, NAM, ASM, K2O/Al2O3, (Fe+MnO)/Al2O3 and (Al2O3+Na2O+K2O). This work was supported by the Russian Foundation for Basic Research (project no. 16-05-00586) and Ministry of education and science of the Russian Federation (project no. 2017-220-06-1656). PRELIMINARY ESTIMATION OF THE NON-DIPOLE PART OF THE GEOMAGNETIC FIELD IN THE QUATERNARY PERIOD BASED ON THE INVESTIGATION OF MARINE MAGNETIC ANOMALIES ON THE CARLSBERG RIDGE Merkuriev S.A.1,2, Demina I.M.1, Ivanov S.A.1 1 - Marine Geomagnetic Investigation Laboratory, SPbF IZMIRAN, St.Petersburg,Russia 2 - Institute of Earth Sciences St.Petersburg State University, St.Petersburg, Russia One of the main principles of paleomagnetology, on which paleotectonic interpretation of paleomagnetic data is based, is the hypothesis of a geocentric axial dipole, i.e., the time-averaged geomagnetic field is well approximated by the field of a central axial dipole located in the center of the Earth and oriented along its rotation axis. However, as more detailed studies have shown, the time-averaged field is largely asymmetric and long-term deviations in the field geometry from the field of a geocentric axial dipole are observed. A convenient method to study these effects is exploring of the inclination anomaly [Cox, 1975], defined as the difference between the observed inclination and geocentric dipole inclination. Marine magnetic anomalies are the records of the history of geomagnetic field reversals. In addition, the shape of the magnetic anomalies depends on the effective inclinations of the ambient magnetic field and the remanent magnetization vectors, and can be numerically expressed by the skewness (asymmetry) parameter (theta). The paleomagnetic analysis of marine magnetic anomalies is based on the determination of the parameter , which is usually performed by inverse phase filtration using the fast Fourier transform for different shift parameters [Schouten, 1972; Schouten and McCamy, 1972]. Knowing values of allows us to find the remanent inclination and makes it possible to estimate the contribution of the averaged non-dipole field. 87 We investigated several dozens of magnetic profiles crossing the axis of the Carlsberg ridge near the equator which cover the axial anomaly (Crone C1n, the Brunhes normal polarity chron) and the adjacent anomalies 2 (Olduvai C2n subchron of the Matuyama chron). A study of the anomalies along the axis of the ridge showed that its shape varies significantly from profile to profile, which leads to a change in the magnitude of the anomalous inclination. The dispersion of the parameter for profiles located within the same segment, where the change in the inclination can be neglected, is apparently related to the influence of the bottom relief and its asymmetrical structure, reflecting the influence of tectonic irregularities both transversally and along the ridge axis. In order to reduce the dispersion within each spreading segment, an algorithm for constructing the averaged profile was used, for which the magnitude of the inclination anomaly was determined, which made it possible to get more reliable . The observed general increase in the inclination anomaly with decreasing latitude, testifies to the predominance of the contribution of the quadrupole component (quadrupole sources) to the averaged non- dipole field in comparison with the octupole field [Merrill and McElhinn, 1977]. Our estimates of the inclination anomaly are close to the estimates obtained from previous paleomagnetic investigations of sediments in the Indian ocean[Schneider and Kent, 1988] and magnetic anomaly profiles from the Galapagos Ridge [Schneider, 1988]. PRELIMINARY MAGNETIC INVESTIGATIONS OF LAKE BOLSHOE MIASSOVO SEDIMENTS (CHELYABINSK REGION, RUSSIA) D. Nurgaliev, D. Kuzina, P. Krylov, L Kosareva, V. Antonenko, P. Yasonov, A. Yusupova Institute of Geology and Petroleum Technologies, Kazan Federal University, Russia During summer field trip was studied lake Bolshoe Miassovo, Chelyabinsk region, Russia (55°09.3’N, 060°17.1’E). The origin of the lake is tectonic. Lake sediments composition are small grained sands, silty sand and black silt. Seismoacoustic investigations were carried out for choose the best places for coring with continuous sedimentation and avoid gas saturated sediments. Overall 10 km of seismoacoustic profiles obtained. Long cores (up to 5 meters) were collected with using special hydraulic corer; short cores (up to 0.5 m) sampled by gravity corer (UWITEC). Measurements of magnetic susceptibility (MS), hysteresis parameters and thermomagnetic analysis were carried out to determine changes in magnetic mineralogy and sedimentation conditions. Measurements were made in the paleomagnetic laboratory of Kazan University. Thermomagnetic curves measured on Curie express balance, coercitive parameters on J- coercivity spectrometer and magnetic susceptibility on multi-function kappabridge MFK1-FA (AGICO). Changes in magnetic susceptibility in first 4.5 meters are not significant, which tells us about stable conditions of sedimentation, below 4.5 meters there is rapid growth of MS. This work was funded by the Russian Science Foundation under grant № 18-17-00251. 88 METHODOLOGY FOR LOW FLYING AEROMAGNETIC SERVICE WITH THE USE OF UAV Parshin A.V.1, Tsirel V.S.2, Rzhevskaya A.K.3 1 – SibGIS LLC, Vinogradov Institute of Geochemistry SB RAS, Irkutsk, National Reseach Technical University, Irkutsk, Russia. 2 – Geologorazvedka JSC, Saint-Petersburg, Russia 3 – Fedorovsky Institute VIMS, Moscow, Russia [email protected], [email protected], [email protected] 1. The idea to use unmanned aviation vehicles (UAV) for aeromagnetic surveys first was put forward first in Australia and Russia in 1995. At present there exist four most successful groups which use this method: in Irkutsk (headed by A.V. Parshin); in Saint Petersburg a group of companies “Geoscan”,( headed by A.E. Semenov) and NPP “Radar MMC” (headed by V.G. Ancev, scientific consultant V.S. Tsirel); in Novosibirsk INGG SB RAS headed by the director of the Institute M.I. Epov. 2. On the basis of their experience a document “Recommendations for low flying aeromagnetic surveys with the use of UAV” was issued on the initiative of VIMS (Moscow). The “Recommendations” were first discussed and later approved by “Rosnedra”. The minutes states that the new method is “… the most rational one in geological prospecting”. So the new method is officially approved. 3. The “Recommendations” treat on the main problems (the most important ones from the point of view of the authors) which are crucial for the adoption of the method. These are, namely, role and place of low height aeromagnetic surveys in the structure of geological prospecting methods; enumeration of existing complexes for low height aeromagnetic surveys. They give a list of survey scales; evaluation of the measurement grid density; classification of surveys according to measurement precision (which introduces a new criterion – precision surveys with the error less than 1 nT, role of the wrong placement of measurement system (as a whole) in the standard error. Special parts are devoted to magnetic variations role in working out a time system for the whole of used apparatus; experience measurements on the plot; provision of topography-geodetic data for a particular flight. 4. The main idea is as follows: the “Recommendations” are, in fact, the only official document supplementing the existing and regulating “Instruction on magnetic measurements” (Leningrad, “Nedra”, 1981, 263 p.). Creation of a new geophysical method makes it possible to change the order of geological prospection stages in the nearest future. 89 PALEOMAGNETISM OF THE UDZHA AND OLENEK UPLIFTS, NORTHERN SIBERIA Pasenko A.M.1, Malyshev S.V.2 1 – The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences, Moscow, 123242, Russia 2 – Institute of Earth Sciences, St. Petersburg State University, 7/9 University Nab., St. Petersburg, 199034, Russia In spite of the fact, that during the last two decades some number of new paleomagnetic poles, more or less meeting the modern standards of quality [Van der Voo, 1993], have been obtained for Neoproterozoic of Siberia [Metelkin et al., 2016, 2010, Pavlov et al., 2015], the problem of the Precambrian segment of the apparent polar wander path (APWP) for Siberia, rests still to be far from its solution. The latter, obviously, hampers the elaboration of Precambrian paleogeographic reconstructions, solution of numerous other important tasks of the Earth Sciences. The Late Precambrian key section of the Udzha Uplift seemed to be one of the most promising object to elaborate the Neoproterozoic segment of APWP of the Siberian platform. Until recently, the rocks composing this section have been considered to be of the Mesoproterozoic, Neoproterozoic and Vendian age. As a result of isotope studies in recent years, the age of formations of the Udzha Uplift has been significantly increased [Gladkochub et al., 2009]. In particular, age of the Udzha Fm, which forms the uppermost part of the Udzha riphean sequence is considered currently to be Mesoproterosoic. On the base of our new paleomagnetic data this formation has been formed about the same time as the Khaypakh Fm from the Olenek Uplift (NE Siberia), whose Mesoproterozoic age has been established earlier from independent isotopic data [Zaitseva et al., 2017]. During last several years we have carried out the paleomagnetic studies of Late Precambrian rocks of the Udzha Uplift including the Mesoproterozoic Udzha and Unguokhtakh formations as well as intrusions representing two Mesoproterozoic magmatic events. As a result of these studies the series of new Mesoproterozoic Siberian paleomagnetic poles has been obtained. These paleomagnetic poles significantly complement the Mesoproterozoic segment of APWP of the Siberian Platform. The research was supported by grant of the Russian Ministry of Education and Science № 14.Z50.31.0017. 90 METALLIC IRON IN BASALTIC LAVA RIVER FROM MALY YENISEI (TUVA, RUSSIA): THE RESULTS OF THERMOMAGNETIC STUDY Pechersky D.M.1, Kazansky A.Yu.2, 3, Kozlovskiy A.M.4, Kuzina D.M.5, Markov G.P.1 1 Schmidt Institute of Physics of the Earth RAS, Moscow, Russia 2 Geological Department of Lomonosov Moscow State University, Moscow, Russia 3 Geological Institute RAS, Moscow, Russia 4 Institute of Geology of ore deposits, petrography, Mineralogy and Geochemistry RAS, Moscow, Russia 5 Kazan (Volga Region) Federal University, Kazan, Russia We present thermomagnetic results on 6 lava flows from Maly Yenisei lava river (51.4 N, 91.4 E) in Tuva region, Russia. The study was carried out in IPE RAS Moscow and Kazan University, Kazan. Titanomagnetite with Curie points 100-120 C° was found as a main magnetic mineral in basalt of lava river. Titanomagnetite is partly undergone heterophase oxidation up to magnetite in some samples. Iron concentration in basalt is rather low and varies from 0 to 0.210-3%. It should be noted that samples where titanomagnetite is completely oxidized to magnetite the native iron is also absent due to the intensive oxidation. Due to Curie points >760°C the iron in Maly Yenisei basalt is close to pure iron similarly all the other terrestrial and lunar objects. The Curie points of 775 ° C and above in Maly Yenisei most likely are due to a small admixture of cobalt in the iron. Metallic iron particles must sink down inside liquid basaltic lava flow, so the iron concentration should increase from top of the flow towards its bottom. Such clear tendency in downwards increase od Fe concentration is observed in flows 1, 3, 5, while in flows 4, 6 it is perturbed and completely absent in flow 2. The perturbations in Fe concentration most likely are caused by turbulent motions inside the flow and low content of metallic iron. However, the rates of downward increase of Fe concentration in flows 1, 3, 5 are very close. Despite wide variation of native iron concentration in different types of basaltic lava (Maly Yenisei lava river, lava river from East Sayan, ocean floor basalts and Siberian traps) the size of the iron particles is practically the same in all cases (similar histograms of iron particle distributions with modes 10–20 µm). This can be explained only by one determining factor - the gravity of the Earth. Therefore, according to the histogram of the size of iron particles, you can try to restore the magnitude of gravity, more precisely - the acceleration of gravity, and hence the mass of the planet. 91 THE AVERAGE SIZE OF IRON PARTICLES VS. THE AGES OF LUNAR BASALTS D.M. Pechersky, G.P. Markov Schmidt Institute of Physics of the Earth RAS, Moscow, Russia Тhe micro-photographs of thin sections of lunar basalt brought to Earth by American spacecraft "Apollo 11-17", was measured the grain size of iron in lunar basalts, with absolute radioisotope Dating. As a result, as seen in Fig. 1, an obvious dependence of the average size of such grains on the age of basalts was found, namely, in the time interval from 3.9 to 3.2 billion years ago. Only two samples deviate from this dependence. The average grain size increased by about 1.6 times (Fig.1), which may indicate, in particular, a significant decrease of the acceleration of gravity on the Moon for the same period of time. Fig. 1. Dependence of the average grain size of "iron" D (µm) in lunar basalts vs. the age of basalts. Hollow diamonds - photo of thin section in transmitted light; filled diamonds in the reflected light. Since the dependence of the grain size on the age of the basalts is, at least for the moon, global in nature, the decrease in the lunar acceleration of gravity can be associated either with an increase in the size of the moon, or with a decrease in its mass, or with both, together. It is impossible to exclude also such, the most courageous, the most nontrivial and the most improbable option as change in time of a gravitational constant. 92 PETROMAGNETIC AND MICROPROBE STUDIES OF PEAT DEPOSITS (PRELIMINARY RESULTS) Peskov A.Yu.1, Chakov V.V.2, Klimin M.A.2, Krutikova V.О.1, Zakharchenko Е.N.2, Arkhipov М.V.1, Didenko А.N.1,3 1 Kosygin Institute of Tectonics and Geophysics, Far Eastern Branch, Russian Academy of Sciences, Khabarovsk 2Institute of Water and Ecology Problems, Far Eastern Branch, Russian Academy of Sciences, Khabarovsk 3 Pacific National University, Khabarovsk Preliminary results of petromagnetic and microprobe studies of peat samples from the stratified section located on the marshy watershed between the Khor and Kia rivers (Khabarovsk krai) are presented. The section is represented by woody grass dark brown peat. Marsh formation took place early in the boreal period about 9000 years ago (radiocarbon analysis – 8890±95 years). The programme of continuous sampling along the 190-cm-thick section included collection of 95 oriented samples. The initial magnetic susceptibility (ϰ) was measured by a Kappa-Bridge MFK-1FA magnetic susceptibility meter (sensitivity 2E-8 SI units). Microprobe studies were performed using a scanning electron microscope VEGA3 LMH fitted with energy dispersive X-ray spectrometer X-Max80. In the course of petromagnetic studies, 3 horizons characterized by an enhanced initial magnetic susceptibility were established: 0-10 cm horizon (mean – 2.13E-06 SI units); 52-56 cm horizon (1.71E-06 SI units); and 176-190 cm horizon (1.44E-05 SI units). The mean ϰ value for the entire section is 2.30E- 08 SI units. Microprobe studies showed that magnetic minerals in samples from the established intervals are clastic particles of titanomagnetite and hemoilmenite series. Particles vary in size from 2 to 200 μm. Magnetite globules from 6 to 14 μm in size (presumably of space origin?) are recognized in the 52-56 cm and 176- 190 cm horizons. In the 0-10 cm and 52-56 cm horizons, spherical forms of carbon of unknown origin measuring from 2.53 to 2.81 μm are found. Thus, most probably particles in the 52-56 cm horizon are from outer space. Anthropogenic sources can account for elevated ϰ values in the 0-10 cm horizon as a result of initial development of the peat bog. The confinement of the 176-190 cm horizon to the contact zone between the overlying peat and the underlying clay minerals does not allow a definitive conclusion to be made as to the reason of enhanced magnetic susceptibility in it. The study was carried out with the financial support of project No. 112/2018D. 93 PALEOMAGNETISM OF THE PIONERSKAYA FORMATION; CONTRIBUTION TO THE GEODYNAMIC MODEL OF THE SIKHOTE-ALIN OROGENIC BELT Peskov А.Yu.1, Arkhipov M.V.1, Kudymov A.V.1, Didenko A.N.1, 2 1 Kosygin Institute of Tectonics and Geophysics, Far Eastern Branch, Russian Academy of Science, Khabarovsk 2 Pacific National University, Khabarovsk The study focused on the Berriasian-Valanginian sandstones of the Pionerskaya Formation (54.09ºN, 140.05°E). Structurally, these rocks belong to the Zhuravlevka-Amur terrane (Khanchuk, 2006, and others), also known as the Amur terrane (Zyabrev, 2011, and others), of the Sikhote-Alin orogenic belt, where it borders on the Mongol-Okhotsk orogenic belt. There are various tectonic zoning maps of, as well as geodynamic models for evolution of the Mongol-Okhotsk and Sikhote-Alin orogenic belts, which differ appreciably (Parfenov et al., 1999, Khanchuk, 2006, Golozubov, 2006, and others). One of the main reasons for this is the almost total absence of paleomagnetic data making it possible to quantify the kinematics of the motion of terranes that make up the orogenic belts. Paleomagnetic studies (AF demagnetization using a 2G Enterprises SQUID magnetometer 755-R) gave a pre-folding (Ks/Kg=6.4) component of magnetization. The average value of natural remanent magnetization (NRM) of the samples studied is 1.4E-03 A/m and magnetic susceptibility (ϰ) is 1.37E-04 SI. The average anisotropy of initial magnetic susceptibility (AMS) is 2.1%. No dependence for AMS and km is found suggesting either the absence or minor influence of secondary processes on the magnetic fabrics in sandstones. Considering the AMS data, calculation of inclination shallowing according to (Bradbury, 2005) yielded ≈7 °. The following coordinates of the ancient component of magnetization were used to calculate the paleomagnetic pole: Decs=305.5°, Incs=34.9°, Ks=11.6, a95s=10° (statistics by samples – N=20). Coordinates of the paleomagnetic pole were: Plat=36.0°, Plong=32.0, dp=6.6°, dm=11.5. The results of the study on the Berriasian-Valanginian sandstones of the Pionerskaya Formation in the northern Sikhote-Alin orogenic belt indicate that they formed at the latitude of 19.2º±6.6ºN meaning that later they moved more than 3 500 km northward along the Eurasian margin. This study was supported by the Russian Science Foundation (project no. 16-17-00015). MAGNETIC PROPERTIES OF SEDIMENTARY ROCKS FROM PIONERSKAYA AND GORINSKAYA FORMATIONS (JUNCTION ZONE BETWEEN THE SIKHOTE-ALIN AND MONGOL-OKHOTSK OROGENIC BELTS) Peskov A.Yu. Kosygin Institute of Tectonics and Geophysics, Far Eastern Branch, Russian Academy of Sciences, Khabarovsk The junction zone between the two orogenic belts in question is represented by Upper Triassic, Lower- Middle Jurassic turbidites of the Ulban terrane and Cretaceous rocks of the Zhuravlevka-Amur turbidite basin. Sandstones of the Gorinskaya and Pionerskaya formations of the Komsomolskaya Group collected 94 in exposed outcrops of Sakhalin Bay were studied. Structurally, these rocks belong to the Zhuravlevka- Amur terrane. The Gorinsky Formation is dominated by sandstones (1100-1300 m); siltstones and their flyschoid interbedding are rare. Its age determined from Buchia-bearing parts is restricted to the Berriasian. Based on Buchia, the overlying Pionerskaya Formation (900-1430 m) is assigned to the Berriasian-Valanginian (Kaidalov et al., 2009). Studies have found that magnetic properties of sandstones from the Pionerskaya and Gorinskaya formations differ appreciably. Mean values of natural remanent magnetization (NRM) differ by more than two orders of magnitude: 1.4E-03 A/m (Pionerskaya Fm) and 3.31E-01 A/m (Gorinskaya Fm). Mean susceptibility (ϰ) values of studied specimens of rocks from the Pionerskaya and Gorinskaya formations are 1.37E-04 SI and 2.98E-04 SI units. Hysteresis parameters were also studied. The average ratios of the hysteresis loop parameters for sandstones of the Pionerskaya Formation are: Irs/Is=0.003; Hcr/Hc=13.2. Data points of rock specimens from the Pionerskaya Formation fall in the multi-domain (MD) particle field on the modified Day’s plot (Dunlop, 2002). Sandstones of the Gorinsky Formation show higher magnetic rigidity than rocks of the Pionerskaya Formation. Their data points plot within the pseudo-single domain (PSD) field - the average values of hysteresis parameters ratios are: Irs/Is=0.14; Hcr/Hc=1.8. The results obtained can be used in paleomagnetic studies, and also as a petrophysical criterion for differentiating rocks during geological surveys. The reported study was funded by RFBR (project no. 18-35-00048). IDENTIFICATION OF MAGNETIC CHRONS BY COMPONENTS OF MARINE BAND ANOMALIES A.A.Petrova, Yu.A.Kopytenko SPbF IZMIRAN, St-Petersburg, Russia It is presented the component model of the Earth's magnetic field (EMF) developed by SPbF IZMIRAN and its application for the identification of sea band alternating anomalies of components. It is considered in order to clarify the reconstruction of tectonic plates, study the nature of changes in the components of the EMF vector for the periods of EMF inversion during the formation of the seabed and study the structure of the Earth's crust of the oceans. The component model of EMF is constructed from the results of vector surveys and values of components calculated from measurements of the absolute vector of the magnetic field induction near the Earth's surface. For the water areas of the North Atlantic and North- West Pacific, models of sea linear anomalies of horizontal H and vertical Z components have been constructed that provide the additional information for reconstructions of the formation of the oceanic crust and the space-time displacements of tectonic plates. 95 ARHEOMAGNETIC STUDIES OF NEOLITHIC CERAMICS OF VEKSA ARCHEOLOGICAL SITE (CONTINUATION) Pilipenko O.V., Nachasova I.E., Markov G.P. Schmidt Institute of Physics of the Earth RAS, Moscow, Russia This work is a continuation of arheomagnetic studies of ceramics of archaeological complex Veksa in order to obtain data about the geomagnetic field intensity in the Neolithic in the center of the Russian Plain. The archeological complex Veksa is located about 20 km north-east of Vologda town (59.2o N, 39.9o E). The thickness of the cultural layers is about 50 m. 41 samples of ceramics were investigated. Burned materials are fragments of pottery, whose color varies from light brown to dark brown. The age of fragments of pottery was determined from C14 method [Nedomolkina, 2004]. Laboratory studies were carried out using the modified double heating Tellier method [Thellier, Thellier, 1959; Coe, 1978] with the control of possible changes in the ability of the sample to acquire a thermal remanent magnetization by measuring the so-called pTRM check-points and pTRM tail-checks. We used for paleointensity estimations only that points, when difference between tail-check and NRM was less than or equal 10% and when difference between check-point and pTRM was less than or equal 10 %. As a result of the studies data about the change of the geomagnetic field intensity recorded in the fragments of ceramics of the archeological complex Veksa in the ~6200-2000 yr BC were obtained. The geomagnetic field intensity in this time interval varies in the range of ̴ 20-65 μT and reached the highest values in the last quarter of the V millennium B.C. The obtained data are in good agreement with the data obtained in archaeological monument Sakhtysh. This work was supported by the State Task of IPE RAS, RFBR (project no. 16-05-00378) and by the Government of the Russian Federation (project no.14.Z50.31.0017). References Coe R.S. Geomagnetic paleointensity from radiocarbonated flows on Hawaii and the question of the Pacific nondipole low // J. Geophys. Res. 1978. V. 83. P. 1740-1756. Nedomolkina N.G. Neolithic complexes of the settlements of Veksa and Veksa 3 of the upper Sukhona basin and their chronology // Problems of chronology and ethno-cultural interactions in the Neolithic Eurasia. S.-P. 2004. V.2. P.265-279. Thellier E., Thellier O. Sur l’intensité du champ magnéttique terrestre dans le passé historique et géologique // Ann. Geophys. 1959. V. 15. Pp. 285-378. 96 NEOPROTEROZOIC GLACIAL DEPOSITS OF SIBERIA: THE PROS AND CONS OF SNOWBALL EARTH HYPOTHESIS Andrey Shatsillo1, Dmitriy Rudko1, Sergey Rudko2,3, Irina Latysheva2, Nikolay Kuznetsov2 1Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences 2Geological Institute, Russian Academy of Sciences 3Institute of Precambrian geology and geochronology, Russian Academy of Sciences Lots of paleomagnetic data shows a low-latitude position of ancient platforms during Neoproterozoic glaciations. In terms of the "Snowball Earth" hypothesis it means, that during this time Earth was totally covered by ice few times. Theoretical calculation shows inevitable closure of polar ice-caps after they reach near 300 latitudes in response to the positive feedback loop between thermal balance and albedo of planet. However, there are no paleomagnetic data showing a high-latitude position for some continent at this time. It can be explained by absence of continental blocks in high latitudes, or by development of glaciations only in low latitudes. The latter is developed in G. Williams' "anti-Snowball" works and can be explained by the dramatic change of the Earth's obliquity angle. In Neoproterozoic sedimentary sequences of Siberia few glacial horizons are known, and their origin is believed to be related with global glaciations. For two of them, we obtained paleomagnetic data indicating the low-latitude position of the Siberian platform during glaciation. Particularly calculated paleolatitude for overlapped by tillites Vandadyk fm. is ~ 90. Paleolatitude for Nichatka fm. containing glacial deposits is ~ 00. Such results are “pros” for “Snowball Earth” hypothesis from one hand. From another hand the results from Nichatka fm. are obtained in deposits resembled modern varves (seasonal-controlled periglacial deposits). We argue this type of varves cannot be formed nor in equatorial areas, nor under global-glaciation conditions. Therefore, the obtained data finds no explanation in terms of “Snowball Earth” hypothesis and may indicate inconsistency of Geocentric Axial Dipole model for Neoproterozoic geomagnetic field. Sedimentological studies are supported by the RSF grant 18-77-00059 and paleomagnetic researches are supported by grant 17-05-00021 from the Russian Foundation for Basic Research. CYCLOSTRATIGRAPHIC ANALYSIS OF LOPATA FORMATION (NE OF ENISEY RIDGE, WESTERN SIBERIAN PLATFORM): MORE ON HYPERACTIVITY OF GEOMAGNETIC FIELD IN THE LATE PRECAMBRIAN Dmitriy Rudko1, Sergey Rudko2, Andrey Shatsillo1, Nikolay Kuznetsov2 1 Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences 2 Geological Institute, Russian Academy of Sciences Recently geomagnetic field hyperactivity has been suggested for the Terminal Ediacaran and its impact on the Cambrian explosion of Life has been supposed [Meert et al., 2016]. The suggestion of 97 hyperactivity is based on the unusually high amount of magnetic polarity zones recorded in some late Ediacaran rocks of Baltica and Siberia. However, quantitative estimates of geomagnetic field reversal frequency have not yet been presented. In Siberia, an anomalous magnetostratigraphic record was detected in the Lopata Fm. redbeds (Yenisei Ridge). Here 58 zones of magnetic polarity were recorded in a 60 m sedimentary sequence. To determine the frequency of magnetic field reversal, the accumulation time of the Lopata Fm. deposits were studied using sedimentological and cyclostratigraphic approaches. The depositional settings of the Lopata Fm. were interpreted as analogues of the wadi channels in modern deserts, which can provide sedimentation rates as low as 0.2 m/1000 years. To estimate the duration of the formation of the sequence examined by the cyclostratigraphic method, magnetic susceptibility (MS) was measured along a section with a step of 0.2 m in the field. According to sedimentological estimates, such measurement frequency should be enough to recognize precession, obliquity and eccentricity astronomic cycles possibly affecting the magnetic characteristic of the rock. The multi-taper spectral analysis of measured MS variations shows a number of peaks on the periodogram which correspond to significant periods of 29.3, 7.1, 1.8, 1.3, 1.0, 0.8 m. Their ratios are very similar, and compared with those for orbital cycles of long and short eccentricity, obliquity and precession (405.6, 94.9, 27.6-36.2, 15.5-22.0 ky) [Berger et al., 1994; Waltham, 2015]. Based on this assumption the 57 inversions of geomagnetic field inversions recorded at Lopata Fm., happened during 1.2 My, suggesting an ultra-high frequency of magnetic field reversal in the Late Ediacaran, which has no analogues in the Phanerozoic eon. Research supported by Program of the Presidium of RAS № 0135-2018-0050 and by grant 17-05-00021 from the Russian Foundation for Basic Research. BERYLLIUM AND RELATIVE PALEOINTENSITY SIGNALS DURING THE LAST GEOMAGNETIC REVERSAL Tatiana Savranskaia1, Jean-Pierre Valet1, Laure Meynadier1, Franck Bassinot2, Quentin Simon3, Didier Bourlès3, Nicolas Thouveny3 1 - Institut de Physique du Globe de Paris, Université Paris Diderot, Sorbonne Paris-Cité, UMR 7154 CNRS, 1 rue Jussieu, 75238 Paris Cedex 05, France 2 - Laboratoire des Sciences du Climat et de l’Environnement (CEA-CNRS-UVSQ), Domaine du CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France 3 - Aix-Marseille Université, CNRS, IRD, Coll France, CEREGE UM34, Technopôle de l’Environnement Arbois-Méditerranée, BP80, 13545 Aix en Provence, France. Record of relative Paleointensity (RPI) and production rate of cosmogenic beryllium (10Be) in marine sediments are both primarily controlled by the evolution of the geomagnetic field, and therefore should show identical variations. However, both indicators depend on complex processes within the sediment, which can bias their relationship with field intensity. The ultimate goal of the present study is to determine which factors can affect the records and subsequently to assess their reliability. To meet this objective we focus on the interval surrounding the last reversal recorded in five sedimentary records from the Indian, West Pacific and North Atlantic oceans. We took advantage of the large changes in beryllium production (given by the 10Be/9Be ratio, subsequently referred as Be-ratio) during this period to check for the consistency of the Be-ratios at the five sites. We scrutinized whether similar Be-ratios were recorded at all sites and found that neither the amplitudes nor the total amounts of Be-ratio were consistent between sites. Various factors linked to bioturbation, lithology and digenesis can be responsible for these 98 differences. Mixing of particles by bioturbation was estimated in three cores from the distribution of Australasian microtektite fragments that were found at the same position below the last geomagnetic reversal. Previous studies pointed out the role of carbonates on Be adsorption by sediment particles. Here the sensitivity of the Be-ratio to the lithology is confirmed by its linear relationship with non-carbonate fraction, but this effect is not large enough to account for the differences in Be production between sites during the reversal. Finally, we compared the RPI and Be-ratio variations during the period surrounding the reversal. The most similar RPI and Be-ratios records were found in two west Pacific Ocean cores, but with out-of-phase signals, resulting from post-depositional remagnetization. We speculate that smearing of RPI signal removed the short-term amplitude variations, which may have improved the similarity between the two signals. APPLYING THE MAGNETIC FORCE MICROSCOPY TO EVALUATE THE MAGNETIC STATES IN ROCKS E.S. Sergienko1, S.Yu. Yanson1, I.A. Vasilyeva1, M.S. Lozhkin1, A. Kosterov1, P.V. Kharitonskii2 1Saint-Petersburg State University 2Saint-Petersburg State Electrotechnical University “LETI” The method of magnetic force microscopy (MFM) is widely used in both fundamental and applied research of magnetic materials. This is one of the most promising tools for visualizing stray magnetic fields and their distribution over the surface of a material. In particular, MFM is used in the development of the magnetic recording materials and optimization of recording regimes of magnetic heads allowing the super-dense information recording, and to study the structure and properties of alloys, nanoparticles, nanocomposite materials, and thin films. MFM is also widely applied in biophysical and biomedical research Petrophysics is another rapidly developing field of MFM application. Potentially, it allows to observe, in situ, the domain structure and magnetization reversal processes in magnetic minerals [cf. Haag et al., Geophys. Res. Lett., 20, 675 (1993); Prévot et al., Phys. Earth Planet. Inter., 126 , 75 (2001); Frandsen et al., Phys. Earth Planet. Inter., 141, 121 (2004); Shaar and Feinberg, Geochem., Geophys., Geosyst., 14, 407 (2013]. To this end, we investigated several types of rocks and minerals with constrasting magnetic properties, aiming to establish general patterns of mapping the distribution of magnetic fields stemming from the cantilever interaction with the sample. Among the studied samples were quartz, flint, magnetite, hematite, pyrite and chalcopyrite, basalts and impact melts: irghizites from the Zhamanshin astrobleme, and tagamites from the Jänisjärvi astrobleme. We found that MFM not only allows to differentiate ferrimagnetic minerals from non-ferrimagnetic, but also to distinguish particular magnetic states (e.g. multidomain from single-domain), detect chemically heterophase magnetic grains, and the presence of superparamagnetic particles. However, in the latter case, the post-processing of the MFM data (correction for the relief, filtering, and signal transformation) is of the crucial importance. This study was partially supported by the RFBR grant No. 18-05-00626 and used the equipment of the resource centers of the Science Park of St. Petersburg State University: Nanophotonics, Geomodel, Resource Center for Microscopy and Microanalysis. 99 NEW 1.86 GA PALEOINTENSITY DATA FROM THE KOLA PENINSULA INTRUSIONS, NE FENNOSCANDIA Shcherbakova V.V.1, Veselovskiy R.V.2,3, Shcherbakov V.P.1, Zhidkov G.V.1, Smirnov M.A.1 1GO “Borok” of Institute of Physics of the Earth, RAS, Borok, Russia 2Institute of Physics of the Earth, RAS, Moscow, Russia 3 Lomonosov Moscow State University, Moscow, Russia [email protected]; [email protected] The Precambrian period occupies ≈ 85% of the Earth’s geological history and accommodates all the main formation stages of the Earth as a planet, including the emergence of its magnetic field. Variations in the time-averaged geomagnetic dipole moment have the potential to inform us about the long-term development of the geodynamo and its response to mantle forcing and the thermal evolution of the core. But the determinations of intensity of the magnetic field during this period are sparse and of limited reliability. A detailed palaeomagnetic study, the palaeointensity determinations Banc and comprehensive investigation of magnetic properties have been performed with the Kola Peninsula poikilo-ophitic sill rocks of the age 1860±4 Ma (according to U-Pb ID-TIMS analysis on baddeleyite grains). The electron microscopic images of thin sections and X-ray diffractograms were performed too. Palaeomagnetic directions calculated after stepwise thermal demagnetization of sills are Danc=352°.4, Janc=56°.8. Rocks demonstrate thermally stable successive curves Msi(T) with clearly pronounced near-magnetite Tc. According to the thermomagnetic criterion, high-temperature pTRMs show typical SD-PSD behavior while low-temperature pTRMs demonstrate PSD-MD characteristics. Some correction for DS of samples was made for Banc data obtained. Palaeointensity determinations by the Thellier-Coe (with the check- points procedure) and Wilson methods were carried out with rocks from 6 sites. Reliable Banc values give generally low palaeofield (less 10 µT) with corresponding VDM values in the range (1.2-2.4)x10^22 Am^2. As seen from the World paleointensity database http://wwwbrk.adm.yar.ru/palmag/index_e.html, the Paleo- and Mesoproterozoic periods (2.5–1Ga) are marked with a noticeably low paleofield intensity with mean VDM = 3.2x10^22 Am^2. Note that this low value led to the formulation of the Proterozoic dipole low hypothesize (Biggin et al., 2009) and our new data support the hypothesize. The work was funded by the grants of RFFI №16-05-00446, of RSCF №16-17-10260 and by the grant of President of Russian Federation MD1116.2018.5. 100 PARADOXES IN THE LATITUDE DISTRIBUTION OF THE GEOMAGNETIC FIELD VECTOR IN THE BRUNHES CHRON Shcherbakov, V.P.1,2,3, Khokhlov, A.V.2,4, Sycheva, N.K.1 1Borok Geophysical Observatory of Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences 2Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences 3Kazan Federal University 4Institute of Earthquake Prediction Theory and Mathematical Geophysics, Russian Academy of Sciences A statistical estimation of the correspondence of empirical data on paleointensity and paleoinclination for the Brunhes chron to the hypothesizes of the Central Axial Dipole (GAD) and the Giant Gaussian Process (GGP) is performed. The estimation is based on a computer simulation of data corresponding to the specified statistical characteristics of the gaussian coefficients of the spherical expansion of the geomagnetic field. The estimates performed have shown that according to the Kolmogorov-Smirnov and Anderson-Darling tests, the GAD hypothesis in its canonical form should be rejected. The extension of GAD to GGP with nonzero time-averaged quadrupole and octupole terms restores the agreement between the empirical data on paleointensity and GGP model. The same is true for the paleoinclination data, but the problem is that these two models are mutually exclusive since their parameters do not agree with each other. Namely, testing of paleoinclination data by the GGP model showed the need for the introduction only relatively small corrections to the purely dipole geomagnetic field. At the same time, the requirement of statistical correspondence of the paleointensity data to the GGP model revealed a necessity to include to introduce a high quadrupole contribution (1/3 of the dipole coefficient value). The most likely cause of such the contradiction may be artifacts associated with erroneous of paleointensity determinations, but even with this interpretation, the question of reasons for the existence of such the strong latitudinal dependence of the virtual axial dipole (VADM) intensity fixed by the empirical data remains unresolved. The work was supported by the state assignment 0144-2014-00117 and the Ministry of Education (contract No. 14.Z50.31.0017). CHECKING THE DIMENSIONS OF COULOMB'S LAW FOR STATIONARY MAGNETIC FIELD AND THE DETERMINATION OF THE DISTANCES TO THE ELEMENTARY SOURCES IN MAGNETOMETRY Sorokin A.G. Federal State Budgetary Institution VIMS Presented are the major complicating factors at measurements of force of magnetic interaction in Ch. Coulomb's experiments in 1785 - 1789. The most significant of them is marked by the effect of the displacement of the position of the magnetic masses due to the influence of the opposite ends of the magnets. The verification of dimensions included in the formula of the Coulomb's magnetostatic law, in 101 which the force of interaction depends inversely on the distance to the sources in the second degree, revealed inaccuracies. Based on the results obtained, it is stated that the force of interaction of magnetic poles is inversely proportional to the distance in the fourth degree. An expression is given for the absolute value of the strength of the total magnetic field vector, in which the field is inversely proportional to the distance in the third degree. Carried out the check of solutions of the inverse problem for simple magnetically disturbing bodies (horizontal and vertical material line, point source) in software packages by different methods of singular points, the most accurate of which confirm the submitted statements about the degrees of distances with high accuracy. ANALYTIC SCALING LAWS IN PLANETARY DYNAMO MODELS Starchenko S.V. IZMIRAN, Kaluzhskoe hwy 4, Troitsk, Moscow, 108840 Russia Numerical models of planetary MHD dynamos have led to many advances in the last twenty years. However, the accessible parameter space of these models is somewhat limited due to computational constraints. A number of numerically based scaling laws have been proposed, but it has been difficult to reliably confirm them from the simulation data alone. Since these scaling laws have to be used to extend the numerical models into the planetary parameter regime, getting correct scalings is an important issue. Here possible balances between the relevant terms in the dynamo equations are considered, and a number of different known and new analytic scaling laws are proposed. Some of these laws are compatible with the famous Christensen-Aubert (2006) scaling for the magnetic field strength. Plausible estimates of the typical values of the important quantities in the Earth’s core and other Terrestrial planets are made, and the extent to which the various scaling laws are consistent with these estimates is discussed. The current millennium started with cheerful blossom of numerical Earth’s/planetary MHD dynamo-like first principal models that were originated by the pioneering work of Glatzmaier and Roberts (1995). Despite tremendous remoteness of the key models’ parameters from the real dynamos, those models were able to reproduce some observable geodynamo / planetary / stars’ features and even to access to the real objects via the scaling laws. Those laws were first based on inviscid limit. In contrast, King and Buffett (2013) demonstrated prevailing viscous control for all the explored models. This paper supplements their numerical estimations by analytic magnetic/energy estimations and formulates the conditions for such viscous regime to exist, while the major goal of this paper is to find the true diffusion-free scaling for the convective MHD dynamos in the Terrestrial planets. Unfortunately, as Cheng and Aurnou (2016) showed it, the available numerical models are principally not able to produce such diffusion-free scaling laws. Thus, because of the limited range of parameter space in which dynamos can be found, several different proposed scaling laws give reasonable fits to the numerical simulation data. The problem is that the numerical models cannot discriminate between a numbers of plausible, but different, scaling laws, while analytic models could hopefully be able to do this at least to some extent. I am trying to do it in the frame of somewhat standard one initially unknown dimension scale (one-scale) scaling (Starchenko and Jones 2002, Christensen 2010) and my (Starchenko 2014) two-scale scaling that is sufficiently improved. The section 2 of this paper is devoted to the known and my new integral conditions those are useful for the further formulations of the searching scaling laws via the simplest possible balances. In the section 3, I explore viscosity dependent and independent planetary dynamo scaling in the frame of classical one-scale scaling. The major section 4 is devoted to my modified two-scale scaling that results in two sets of scaling laws with moderate and strong domination of magnetic energy over kinetic one. In the final section 5, I draw conclusions and discuss applicability limits of my and others scaling laws. References 102 Cheng, J.S., Aurnou, J.M., 2016. Tests of diffusion-free scaling behaviors in numerical dynamo datasets. Earth and Planetary Science Letters, 436, 121–129. Christensen, U.R., Aubert, J., 2006. Scaling properties of convection-driven dynamos in rotating spherical shells and application to planetary magnetic fields. Geophys. J. Int., 166, 97–114. Christensen, U.R., 2010. Dynamo Scaling Laws and Applications to the Planets. Space Sci Rev., 152, 565-590. Glatzmaier, G.A., Roberts P.H., 1995. A three-dimensional convective dynamo solution with rotating and finitely conducting inner core and mantle. Phys. Earth Planet. Int., 91(1–3), 63–75. King, E.M., Buffett, B.A., 2013. Flow speeds and length scales in geodynamo models: The role of viscosity. Earth Planet. Sci. Lett., 371, 156–162. Starchenko, S.V., 2014. Analytic base of geodynamo-like scaling laws in the planets, geomagnetic periodicities and inversions. Geomagnetism and Aeronomy, 54(6), 694-701. Starchenko, S.V., Jones, C.A., 2002. Typical velocities and magnetic field strengths in planetary interiors. Icarus, 157, 426–435. VARIATIONS OF ENERGY AND POWER FOR A POTENTIAL GEOMAGNETIC FIELD SINCE 1840 S.V. Starchenko and S.V. Yakovleva Pushkov Institute of terrestrial magnetism, ionosphere and radio wave propagation, Kaluzhskoe Hwy 4, Troitsk, Moscow, 108840 Russia [email protected]; [email protected] Probably for the first time, independent on spherical radius spatial-spectral components of energy and power of the potential part of the main geomagnetic field were determined and investigated. The energy is obtained by integrating its known radial density from the Earth’s core to infinity, and power is a time derivative of energy. Based on three well-known observational models of the geomagnetic field, the total and spectral variations of energy and power have been analyzed from 1840 to 2020. The total energy (~ 6∙1018 J) and power (~ 108 W) are determined by the sum of odd harmonics: dipole n = 1, octupole n = 3, etc. The dipole dominates and its energy is close to the entire energy of the field symmetric with respect to the rotation axis. The energy variations are ~ 10% and are similar for all models except for the "splash" of the IGRF model in 1945-1950. A comparative spectral analysis showed that the "splash" is concentrated in n = 9 and 10, and the variations of the other harmonics are similar in all models. In this case, n = 3 dominates over n = 2. The decrease is fixed for n = 3 to n = 8, and then the dominance of n = 9 over n = 8 and n = 10. The average powers close to zero at n > 1 indicate an almost periodic behavior of the non- dipole field, and the significant power variations indicate a strong non-linearity of the geodynamo. The results of the work are consistent with modern geodynamo-like models. Such a significant IGRF "splash", which can have a nonlinear geodynamo nature, is a real challenge. Alternatively, this may be some artificial shortcoming of the IGRF model. One more reason is the fact that two other "quiet" models were exposed to excessive smoothing. In any case, this feature, discovered by us, earns the close attention of the world's geomagnetic and dynamo community. 103 RECONSTRUCTION OF JURASSIC SEDIMENTARY ENVIRONMENTS USING ROCK-MAGNETIC DATA IN THE MIKHAYLOVTSEMENT REFERENCE SECTION (RYAZAN REGION, RUSSIA) Stepanov I.A.1, Kazansky A.Yu.1,2, Kosareva L.R.3, Rogov M.A.2, Tesakova E.M.1,2, Shchepetova E.V.2 1- Geological Department of Lomonosov Moscow State University, Moscow, Russia 2- Geological Institute of Russian Academy of Sciences, Moscow, Russia 3- Kazan (Volga Region) Federal University, Kazan, Russia The Mikhaylovtsement reference section (54°12'43.0"N 38°56'13.0"E) is located in the quarry where about 20 m of Jurassic mudstones, clays, silstones and sands are exposed. Abundant ammonites and microfossils occurred throughout the section enable to identify the age of the succession as Early Callovian–Early Oxfordian. The purpose of the study is to reconstruct sedimentary environments and their evolution during this time interval on the base of rock magnetic data, and to compare them with lithofacies, micropalaeontological and paleoecological data. We used magnetic hysteresis with decomposition of coercive spectra as a main magnetic method. Thermomagnetic analysis Js(T) was used for determination of magnetic minerals. The main result of the study is rock-magnetic model that is proposed for reconstruction of sedimentation history of Mikhaylovtsement succession during the Early Callovian – Early Oxfordian. The model includes 7 rock-magnetic zones corresponding to different sedimentary environments and gives the base for the following conclusions: 1) The origin of ferromagnetic fraction in the studied sediments is mostly biogenic. It is represented by single-domain greigite originated from magnetotactic bacteria. 2) Regularities in alternation of rock-magnetic zones over the section allow to determine the boundaries of transgression-regression (T/R) events. Three T/P events corresponding to rock-magnetic zones 3-5 are fully confirmed by ostracod analysis. Additionally 2 independent T/P events are recognized in rock magnetic zones 6 and 7 only by ostracod data. 3) On the base of appearance of coarse-grained magnetite and increase of paramagnetic content (not associated with Fe-sulfides and carbonates) the intervals of intensive terrigenous input were recognized. 4) The primary variations in the organic matter content have been recognized due to irregular increasing of pyrite concentration in the sediments. Those conclusions not only coincides with the modern viewpoints on the evolution of the sedimentary environment in the Mikhaylovtsement reference section but also provide the additional information especially in determination of magnetic minerals, their sizes and genesis. This study has been supported by the RFBR, project no. 18-05-00501 (TEM) has been carried out following the plans of the scientific research of the Geological Institute of RAS, project no 0135-2018- 0051 (SEV) and according to the Russian Government Program of Competitive Growth of Kazan Federal University (LRK). 104 СOMPUTER MODELING OF THELLIER AND WILSON METHODS ON SD GRAINS CARRYING TRM AND CRM Sycheva, N.K.1, Shcherbakov, V.P.1,2 1 Borok Geophysical Observatory of Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences 2 Kazan Federal University The Haig’s mechanism of CRM acquisition when CRM is acquired as a result of growth of ferrimagnetic grains in an external field B at a constant temperature TCRM is considered. The computer simulation was performed by the Monte Carlo method taking into account the magnetostatic interactions between the grains. The initial particle size was set in the interval 33-37 nm (TCRM = 400° C) and 44-47 nm (TCRM = 500 ° C) so that on laboratory time scales these particles were superparamagnetic. The final sizes of the blocked particles ranged from 40 to 90 nm. The resulting CRM + pTRM was "thermally demagnetized" when the ensemble was "heated" to TC = 585° C. The formation and "thermodemagnetization" of TRM were carried out with a similar scheme. Each Arai-Nagata diagram display extended close to straight line segment by which it is possible to determine the "paleointensity" but its value always turns out to be 2-3 times lower than the true field used in the course of modeling. The same underestimation was also observed for the Wilson’s diagrams. Similar results were obtained for noninteracting grains so the presence of interaction cannot be the cause of the similarity of the blocking temperature spectra. The work was supported by the state assignment 0144-2014-00117 and the RFBR grant 17-05-00259. STRUCTURAL TRANSFORMATIONS OF TITANOMAGNETITE IN NATURAL BASALTS OF THE RED SEA DURING OXIDATION Tselebrovskiy A. N., Maksimochkin V. I., Grachev R. A. Lomonosov Moscow State University, the Faculty of Physics Paleomagnetic studies are based on an analysis of the primary, or thermo-resistant, magnetization of rocks. The problem of separating the thermic and chemical components of magnetization has not been solved yet. An erroneous interpretation of the nature of magnetization can significantly affect the results of determining the paleointensity. In this work, samples of basalts from the rift zone of the Red Sea, with an average content of ulvospinel of 52 % and a Curie temperature of 260 °C, were annealed during 4.5–110 hours, at a temperature of 350 °C. Then SEM, TEM and XRD studies were conducted on the obtained states to determine the structure and changes in the elemental composition in grains of titanomagnetite. It has been established that with an increase in the annealing time up to 110 hours, the lattice parameter decreases from 8.455 Å to 8.417 Å. At the same time, the Curie temperature rises from 260 °C to 490 °C. This behavior is typical for single-phase oxidation. Deviations from the cubic structure were found in the sample with the maximum annealing time. The sample with the longest annealing time was then held in an atmosphere of pure argon (99.99%) for 40 minutes at 610 °C. After this exposure, TEM showed an increase in the lattice parameter to the initial value and a return to the cubic structure. At the same time the Curie temperature fell from 490 °C to 265 °C. On the investigated grains of titanomagnetite less than 105 10 micrometers in size, TEM and STEM showed no structural or elemental inhomogeneities, which also indicates a single-phase oxidation process. The results of the work show that annealing basalts in air at a temperature of 350 °C leads to a single- phase oxidation of titanomagnetite. Subsequent heating to 610 °C in argon atmosphere promotes its reduction. This work was supported by the RFBR (project № 16-05-00144). MORPHOLOGY AND COMPOSITION OF FOSSIL COSMIC DUST FROM VARIOUS SOURCES Tselmovich V.A.1, Kuzina D.M.2, Nourgaliev D.K.2, Garin E.V.3. Philippov D.A.3 1Borok Geophysical Observatory IPE RAS, Borok, bldg. 142, Borok 152742, Nekouz district, Yaroslavl reg., RF 2Kazan Federal University, ul. Kremlevskaya 18, Kazan, 420008, RF 3Institute for Biology of Inland Waters named after I.D. Papanin RAS, 109, Borok, Nekouz District, Yaroslavl Reg., 152742, RF Using a microprobe, the morphology and composition of the magnetic component of cosmic dust (CD) of various origins were studied. CD constantly arrives on the Earth and accumulates in various environments (peats, sedimentary rocks, etc). Extraction of CD were made by using neodymium magnet. However, with the particles of our interest were extracted particles of volcanic and anthropogenic origin. They differ in size, morphology and composition. The correct identification of particles depends on the capabilities of the microprobe and the art of the operator and has a stochastic nature. It is important to have a set of criteria to reliably identify the CD. Such criteria have been developed. To identify the features and differences of CD from various locations, a spatial slice consisting of 4 sampling points and a time slice were considered. The time slice presented by different age-dated specimen from the sediments of the lake Pleshcheyevo with age from 556 to 6071 BC. The spatial section was represented by peat from flat marshes from the Myshkin and Nekouzsky districts of the Yaroslavl Region, peat from the Tunguska space body (background peat horizons) fall site, from a peat borehole in the Kabardino-Balkarian Republic (sphagnum marsh, 1764 m ASL). It was shown that the common features of CD are: 1) Mt balls with a detrital structure formed during meteorites entering to the Earth’s atmosphere; 2) Mt micrometeorites with a well-crystallized surface; 3) particles of pure native Fe with a size from 1 μm to 500 μm; 4) native metals (Zn, Ni, Cu, W, etc.); alloys and intermetallides (FeNi, FeCr, FeAl, FeW, CuZn, etc.). In this case, particles larger than 50 μm had signs of melting as a result of heating in the Earth's atmosphere during a fall. Particles smaller than 50 μm reach the Earth's surface without heating. It is noted that the ratio of the amount of CD and terrigenous substance in flat peat is higher than in peat selected in the mountains. The peculiarities of the composition of CD can be attributed to a different ratio of the amount of pure Fe and intermetallides, as well as a set of intermetallic compounds, specific for each analyzed point of selection. In some samples, the presence of nanodiamonds and carbonaceous microspheres was noted. The study showed spatial and temporal homogeneity in the composition of the CD flux arriving on Earth in the Holocene. The catastrophic layers were not considered. Supported by AAAA-A17-117040610183-6 and RFBR, 16-05-00703a. 106 THE POSSIBILITY OF DETERMINING THE AGE OF THE NORASHEN SECTION OF LAKE SEVAN A.A. Vardanyan, R.Y. Stakhovskaya Institute of Physics of the Earth, Russian Academy of Science, Moscow Complex magnetostratigraphic and magnetochronological studies of the Holocene sediments of the Sevan basin were carried out at the mouth of the Argichi river near the South- Western shore of Sevan lake. The most interesting section is located 3.5 km from the village of Lchashen (near the village Norashen) in the recess of the highway, in the study of which was found buried under lake sediments ancient Norashen settlement. Lake sediments here are leaned against young andesite-basalts under the canopy. The apparent thickness is 4.5 km. The structure of deposits indicates a two-fold rise in the level of Lake Sevan. The first, the most ancient transgression, is recorded in the sediments of the interval 3.0 – 4.5 m. It was separated by very short-term regression or temporary retreat of lake waters, expressed by swamp soil of 3.60- 3.70 m interval. The time of completion of this transgression was determined by the shells of mollusks from a depth of 3m. Limnaea stagnalis (L.), L. (Radix) ovata (Drap.), planorbis (L.), Gyraulus laevis (Alder), pisidium casertanum (Poli), Succinea obionga (Drap) have been studied by the radiocarbon method, which showed the figure of 6270 ± 110 (MGU -215) at a depth of 3 m. The second transgression is reflected in precipitation of the range 0.50 -1.50. Clam shells from a depth of approximately 1 m: Limnaea stagnalis (L), L. (Radix suricularia (L.)), Valvata Piscinalis (Mull) Planorbis planorbis (L.), Pisidium casertanum (Poli), Succinea putris (L). Their age by C14 at a depth of about 1 m is 2090 ± 70 (MGU -244). Thus, for more than 4,000 years between these two transgressions, the waters of Lake Sevan stood at a lower level. The cultural horizon of the interval 1.50 -2.95 m shows that during this time on this stretch of coast twice settled people - in the III Millennium and in the middle of the II Millennium. The break in the settlement lasted at least 500 years. Available data suggest that over the past 5,000 years people have lived on the shore of lake Sevan. Early bronze, that is, the culture of the III Millennium BC, in the Norashen section is expressed in three layers, the thickness of which is about 1.45 m. The lower building layer has a dark gray color, sometimes black, contains layers of ash. In the upper part of the lake sediments at a depth of 2.95 m mounted floor of pebbles of volcanic origin, which is smeared with clay on top. The layer contains a large number of bones of small and large cattle, bones of a dog and a horse, reptiles, amphibians, fish, bones of birds, usual stone and bone tools, playing circles and a large number of black-absorbed ceramics. There are shells of freshwater and terrestrial mollusks. Above the lower layer is the middle layer of brown color with thickness of 25-30 cm, the floor is also mounted with small pebbles and top smeared with clay, rich in ceramics and animal bones. The floor of the top layer consists of two layers: the lower layer has a dark olive greenish color, and the upper - light. Shards of black-flattened ceramics and animal bones were found in the layer. Traces of fires were also found. The thickness of layer is 30 cm. The late bronze age is characterized here by a layer of light brown with a grayish tinge in the thickness of 20-25 cm, which is located above the upper construction layer of the III Millennium with a break in sedimentation is about 500 years old (due to a decrease in the level of lake Sevan). A small amount of ceramic debris found in the layer enables this layer to be pre-dated to the middle of the II Millennium. Thus, archaeological and radiocarbon data make it possible to accurately determine the age of the Norashen section, which gives the right to consider it quite favorable for the study of the paleovecal variations on the Holocene sediments. 107 ESTIMATION OF SUITABILITY OF SEDIMENTS OF THE SECTION OF DZKNAGNET RIVER FOR STUDYING THE FINE STRUCTURE OF GEOMAGNETIC FIELD A.A. Vardanyan, R.Y. Stakhovskaya Institute of Physics of the Earth, Russian Academy of Science, Moscow Sedimentary rocks both marine and lake are very suitable for paleomagnetic inquiries because sedimentation in water bodies is the most uniform and continuous process, the least susceptible to disturbances of all known in geology processes. With this purpose we chose the Dzknagnet section, sediments of which, as previous studies showed, are very suitable for paleomagnetic inquiries. The Dzknagnet section is located on the left bank of the Dzknagnet River, in the site where the river drains into Sevan Lake. Samples for dating were taken at a depth of about 2 m from the sand layer with great amounts of well-conserved mollusk shell and wood. The С14 dating yields for this depth the age of 940 ± 220 (on shells) and 1010 ± 250 years (on wood). The behavior of the magnetic parameters suggest that ferromagnetic fraction in sediments is not modified, which is evidenced by similarity in the curves Irs(T), Is(T ). The sharp distinction of the average values of J and D in the lower section is believed to be related to the tectonic history of the region. The Zijderveld curves taken from two-thirds of the collection samples showed the presence of three components that appeared at the corresponding temperatures of (1) - 250С, (2) -350С and (3)-500С. The components are likely to be associated with (1) – titanomagnetite, (2) – titanomaghemite and (3) – magnetite. The component analysis is made difficult by the fact that at temperatures on the order of 200С not only the magnetization of the first component Tc, but also the viscous magnetization will be removed. Judging from a great scatter of results in determining this component, an essential fraction of the viscous magnetization is not natural, but of laboratory origin. Clearly this component cannot be used for studying secular variations. Variations by archaeomagnetic data are resolved with an accuracy of ±10%.As it easy to see geomagnetic variations revealed in the Dzknagnet section and those from archaeomagnetic data differ from each other within the errors of their determinations. Comparison of the results obtained from our study of sediments in the Dzknagnet section to archaeomagnetic data for the same time interval and in the same region showed that the paleomagnetic record gives correct representation of geomagnetic field variations. This permits us to assess with the credence the data of secular variations from paleomagnetic studies that due to continuity of data series offer a certain advantage over the archaeomagnetic method. At the sedimentation rate of 26 years/level the found variations have the periods 169±26, 230±26, 380±26, 660±26, 910±26 years. The 180, 360, 600 and 900 year periods are known from both direct and archaeomagnetic observations, the 230-year variation exhibiting only in the scalar parameters may be related to climatic changes and no suppositions exist to the 280-year variations. 108 FOUR INDEPENDENT ISOTOPIC GEOCHROMETERS IN PALEOPROTEROZOIC DOLERITES FROM THE KOLA PENINSULA AS THE BASIS FOR THE NEW ~1.86 GA FENNOSCANDIAN KEY PALEOMAGNETIC POLE Veselovskiy R.V.1,2,3, Samsonov A.V.3, Stepanova A.V.4, Sal’nikova E.B.5, Larionova Yu.O.3, Travin A.V.6, Arzamastsev A.A.5, Egorova S.V.4, Erofeeva K.G.3, Stifeeva M.V.5, Esenkov A.A.1, Chistyakova A.V.1 1 – Geological department, Lomonosov Moscow State University, Moscow, Russia 2 – Schmidt Institute of Physics of the Earth RAS, Moscow, Russia 3 – Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry RAS, Moscow, Russia 4 – Institute of Geology, Karelian Research Centre RAS, Petrozavodsk, Russia 5 – Institute of Precambrian Geology and Geochronology, Russian Academy of Sciences, Saint Petersburg, Russia 6 – Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences, Novosibirsk, Russia We present the results of detailed paleomagnetic studies of Proterozoic dolerite sills exposed within the Murmansk block of the Fennoscandian Shield for more than 200 km of the coastline of the Barents Sea. The paleomagnetic pole, which we consider as the new key pole for Fennoscandia, is calculated from the mean direction of the ChRM in 15 sites, representing at least 8 independent intrusive bodies. The backed contact test was undefined in all cases due to weak magnetization of the host rocks, mostly granites and gneisses. Because the ChRM has only one polarity, we couldn't use the reversal test. Thus, in order to determine the time of the ChRM’s acquisition, we used four independent methods of the isotope dating. Complex studies of U-Pb, Sm-Nd, Rb-Sr and Ar/Ar (biotite) methods were carried out for a thick (about 30 m) sill. The U-Pb method on baddeleyite gave a concordant age of about 1.86 Ga; estimates of the isotope age, obtained by other methods, are consistent with this date. The obtained data indicate pretty the same time of the closuring of four radiogenic isotope systems in different magmatic minerals of the Paleoproterozoic (1860 million years) dolerite sills on the Murmansk craton. The present study is a rare example, when the timing of magnetization is surely proved in the absence of the possibility of applying field tests or if their result is not determined. This work was funded by the grants #16-17-10260 (RSF), #14.Z50.31.0017 The Russian Government), MD1116.2018.5. 109 ROCK MAGNETISM AND PALEOMAGNETISM OF THE EDIACARAN SEDIMENTS OF THE YENISEI RIDGE VOROGOVKA SERIES E.V. Vinogradov, D.V. Metelkin, V.V. Abashev Novosibirsk State University, Novosibirsk Trofimuk Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk The dynamics and time of the separation of Siberia from the structures of Rodinia remains one of the most controversial issues in the reconstruction of the geological history of the Siberian Platform. Paleomagnetic data are very important in resolving existing contradictions under the condition of a well- founded and detailed paleomagnetic study of the Neoproterozoic geological complexes of Siberia. Such complexes are located on the framing of the Siberian craton, forming, in the main, sedimentary sequences. The paper gives new paleomagnetic data from the Vorogovka Series on the Western margin of the Siberian Platform. The Vorogovka Series is a complex of carbonate-terrigenous sedimentary rocks, preserved in small graben-synclinal structures in the northwest of the Yenisei Ridge. The recent data indicate that the age of sedimentation within the Vorogovka Basin is less than 585 Ma. Bottom-up in the stratigraphic sequence, the Vorogovka Series is divided into the Severnaya Rechka, the Mutnina and the Sukhaya Rechka Formations. There are at least 3 regular components of the magnetization in the rocks of the Vorogovka Series. The stable part, probably of an orientational origin, is found only in the rocks of the Sukhaya Rechka Formations, is primary and corresponds to the magnetic field that existed during sedimentation. The remaining regular components are metachronous and reflect the different stages of the Paleozoic geological history of the northwest of the Yenisei Ridge. Using the Halls method, the directions of high-coercive component for Sukhaya Rechka Formation were established. The paleomagnetic pole is located at Plat=-29.3°; Plon=41°; with 95% confidence radius B95=2.1°. The site-means of high-coercive component have the best clustering in stratigraphic coordinates. The maximum K-statistics (Kmax=699) is achieved at 109.8% of unfolding, thus, the fold test shows that the acquired magnetization is pre-folded. In accordance with this definition, the paleogeographic position of the Vorogovka Basin at the time of formation of the studied rocks should correspond to the equatorial latitudes of the southern hemisphere (PL =-8.1°). The work was supported by the Ministry of Education and Science of the RF (project No. 5.2324.2017/4.6) and the RFBR (project No. 15-05-01428). 110 DATE OF TRM OF GRANITE BATHOLITH: IS IT POSSIBLE? Vodovozov V.Yu.1,2, Zakharov V.S.1, Zverev A.R.1,2, Travin A.V.3 1 – Lomonosov Moscow State University, Faculty of Geology 2 – Geological Institute RAS 3 – Institute of Geology and Mineralogy SB RAS The time gap between crystallization and the formation of TRM in large intrusions can reach great values. Probably the only way to directly determine the age of TRM is to date using isotope data on various minerals (the thermochronology method). Mathematical modeling of the cooling rate makes it possible to simplify the research. In a similar way was in the study of the Early Proterozoic granites of the Kodar complex in the south of the Siberian craton. Granite batholiths lie in the Olekma block of the Aldan Shield. We studied for paleomagnetic analysis 769 samples from 5 massifs – At-Bastakh, Hani, Kemen, Ikabi and Kodar. Everywhere there were rocks suitable for obtaining a paleomagnetic poles. Primary nature of the high-temperature components of the NRM is confirmed by positive reversal test and coincidence of directions in the remote intrusions. Paleomagnetic pole Plat = -21.9 Plong = 101.8 A95 = 8.2 is obtained by averaging the poles of 5 massifs. Biotites and feldspats were sampled from the granites of At-Bastakh for 40Ar/39Ar investigations. A total of 12 spectra were obtained: the apparent ages of biotites lie within a narrow interval, 1837-1859 Ma, and the age of the feldspats were strongly rejuvenated. Taking into account the U/Pb zircon age of 1873+/-3 Ma (Larin et al, 2000), we obtained an interval of about 20 Ma between crystallization of the rock and cooling down to 300 degrees. Such a value is difficult to obtain with the help of mathematical modeling. Preliminary mathematical modeling showed that at "instantaneous" intrusion the time gap between the closing temperatures of the isotope systems of zircon and biotite does not exceed 1 million years. The most likely explanation for the discrepancy is the time-stretched intrusion, because all massifs have a two- or three-phase structure. The study was supported by the RFBR, grant No. 17-05-01132. CORRECTION FOR A WEAK RESIDUAL MAGNETIC FIELD IN THE FURNACE DURING THE PALEOINTENSITY DETERMINATION BY THELLIER-COE METHOD Zhidkov G.V. Borok Geophysical Observatory of Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences It is assumed that during a paleointensity determination by Thellier-Coe method one of the double heating-cooling cycles in a furnace shall occur in absence of a magnetic field, i.e. at zero field. However, in practice there exists residual magnetic field vector F0 = {F0x, F0y, F0z}. In the thermomagnetometers and the electric furnaces of the Borok geophysical observatory this field is estimated at 1 μT. This is reflected in the Arai diagram in that the NRM value doesn’t disappear to zero with temperature T increasing. At the same time the NRM components pass by the origin in the Zijderveld diagram and go toward the F0. Consequently, it produces an error in the Thellier-Coe paleointensity determinations of the 111 order intensity of F0. Here it is proposed a correction algorithm to remove this error based on the following equations. (1) After first heating to temperature T1 the magnetization vector M1of the sample: M1 = NRM(Tc,T1)+pTRM(T1,T0,F0) (2) Accordingly, after second heating to T1 the magnetization vector M2of the sample: M2 = NRM(Tc,T1)+pTRM(T1,T0,F0)+ pTRM(T1,T0,FL), where FL is the laboratory field. (3) pTRM(T1,T0,FL) = M2(T1) – M1(T1) (4) If F0 components (F0x, F0y, F0z) are known then the components of pTRM(T1,T0,F0) are: pTRM (T1,T0, F0x) = F0x * pTRM (T1,T0,FL) / FL pTRM (T1,T0, F0y) = F0y * pTRM (T1,T0,FL) / FL pTRM (T1,T0, F0z) = F0z * pTRM (T1,T0,FL) / FL (5) From (1) and (4): NRM(Tc,T1) = M1(T1) – pTRM(T1,T0,F0) The algorithm was successfully applied during the paleointensity determinations in GO Borok. This work was supported by RFBR grant 16-05-00446. PALEOMAGNETISM OF THE EARLY PROTEROZOIC BASITE COMPLEXES OF THE OLEKMA BLOCK OF THE SOUTH OF THE SIBERIAN CRATON Zverev A.R.1,2, Vodovozov V.Yu.1,2 1 – Lomonosov Moscow State University, Faculty of Geology 2 – Geological Institute RAS This paper presents the results of the paleomagnetism study of the Tsina gabbroids (U/Pb age for zircons 1867+/-3 Ma), Kuranakh (U/Pb age for zircons 1863+/-9 Ma) and Doross (U/Pb age for baddeleyite 1752 Ma) complexes. The work purpose is to obtain paleomagnetic poles for studying the structure formation of the Siberian craton’s south at the Early Proterozoic end. Samples of Tsina complex’s gabbroids were selected in the petrotype - Tsina massif and 7 intrusive bodies. The pole of the Tsina complex is calculated by averaging the two paleomagnetic poles - the Tsina massif and other intrusive bodies: Plat = -18.3o Plong = 93.1o A95 = 10.5o. Diabases of the Kuranakh complex were selected in 4 intrusive bodies. High-temperature NRM components, antipodal to the components of the Tsina complex, are distinguished here. It was possible to obtain a positive contact test for the Kuranakh complex. Paleomagnetic pole of the Kuranakh complex: Plat = -22.7o Plong = 102.3o dp/dm = 5.6/10.9. Gabbroids of the Doross complex are selected from 8 intrusive bodies. Many samples have a large NRM value. The average directions of the sites are placed on the stereogram practically chaotically, there is only one cluster of 3 sites. The pole calculated by this direction: Plat = -30o Plong = 79.3o dp/dm = 2.5/4.9. The poles of the Tsina and Kuranakh gabbroids practically coincide with the same-aged poles of the Olekminsky block and the Baikal ridge, which indicates the consolidation of the craton south by 1870 Ma. The pole of the Doross gabbroids differs from the one-age poles of the Baikal ridge, further research is required to explain this difference. The study was supported by the RFBR, grant No. 17-05-01132. 112 113 SECTION S. SEISMOLOGY Conveners - Prof. T.B. Yanovskaya, Prof. V.N. Troyan Seismology and phenomena in the Earth's interior and in the near-Earth space related to earthquakes including: Theory of seismic wave propagation Earth's structure from seismic data Global and regional seismicity and earthquakes sources Phenomena related to earhquakes: Electromagnetic anomalies, Seismic noise, Earthquake precusors, Slow tectonic movements Methods for seismic data processing Methods of seismic prospecting TECTONIC PLATES MICROMOTIONS CAUSED BY THE CHANDLER WOBBLE Blagoveshchenskaya Elena SPbF Izmiran, St.Petersburg, Russia The problem of the correlation of the global dynamic phenomenon "Chandler wobble" with the local dynamics in different parts of the Earth's crust and lithosphere is wide of the solution. In this paper the trail to examine this problem using variation in the monotonous secular process of seismotectonic deformation in the restricted geospace volumes (GSV) around the uniform seismoactive regions is made. Some ideas, concepts of the plate tectonics model and its global map are used. The Euler or Chandler wobble is free rotation mode of the Earth. Its driver is the deep mantle- the most hard and most massive Earth's layer, whose large inertia tensor value is able to keep up Chandler's specific rotation of the Earth for a long time. In the geocentric coordinate system where daily rotation is absent, Chandler wobble occurs to be the main (very slow) rotation of the Earth (as the whole) around the current equatorial axis. We denote this angular rotation velocity vector as E14(t), using "14" as a symbol of the Chandler's phenomenon. The pole of E14(t), EP14(t) moves along the equator eastward(s) passing its 360o in about 14 months (430 days). Chandler wobble influence on the array of numerous seismic events in the GSV (during long time, 1965-1990) we determine by the function EP14gsv which indicates the most typical position EP14(t) the when the earthquakes used to occur. We investigated numerous GSVs and discovered that for many of them it is possible to determine EP14gsv. Large GSVs around mid-ocean ridges in the southern latitudes (2 - 55)S in the Atlantic Ocean, 114 in the Western Indian Ocean and in the Pacific Ocean have reliable EP14gsv parameters, and they prove to be different. This fact indicates that Chandlers wobble influence indeed has some space factor. EP14gsv examples around the West African tectonic plate (with deep Archean roots) indicate, that this equatorial plate is drawing into Chandler's rotation most effective if the EP14(t) is not far from the plate's center of inertia. For these examples and examples for GSVs in Tibet, Himalaya or Zagros as regions of collision and for other GSVs some comparisons with the classic tectonic plate motions were made. Seismic data (1965-1990, M=2-6) were taken from USGS catalog (http://earthquake.usgs.gov). Astronomic data were taken from (Kotlyar and Kim, 1994). SHORT-TERM PRECURSORS OF EARTHQUAKES Dovbnya B.V. Borok Geophysical Observatory of IPhE RAS, Yaroslavl Region, Russia According to magnetic measurements at two mid-latitude observatories, the Borok Geophysical Observatory (58.1 ° N, 38.2 ° E) and the Geophysical Observatory College (64.9 ° N, 212.0 ° E), low- frequency (0 to 5 Hz) electromagnetic signals tied to earthquakes in time and not correlated with other geophysical phenomena were detected. The timing of the signal relative the time of the earthquake ranged from tens of seconds to the first units of minutes with a statistical significance p = 0.87. Signals from remote earthquakes were observed in Borok and College in the form of either single or paired impulses (less often as a series of pulses). In 70% of the total number (about 400) they were observed before the earthquake. The lead time was 1 to 5 minutes. Precursors were recorded before the devastating earthquakes in Japan, China, Romania, before earthquakes in Turkey and other seismically active regions. A remarkable property of the precursor repeatability was found in the character of the described seismoelectromagnetic activity. If the main earthquake was preceded by an ULF electromagnetic pulse, then repeated seismic events in the same region (aftershocks), also can be preceded by anticipatory signals. In this case, the type of emission (single or paired pulses) remains unchanged for the entire series of aftershocks. The physics of precursors is far from obvious. It is clear that each of these signals is one of the manifestations of processes that occur before earthquakes, and in one way or another, are connected with it. Usually, induction and piezomagnetic mechanisms are considered as a possible cause of generation of seismoelectromagnetic signals. The riddle is the appearance of two or more consecutive pulses, as a manifestation, apparently, of similar processes in the terrestrial interior. Perhaps the explanation should be sought within the framework of the Reid model, in which an earthquake is associated with the destruction of cohesion on the boundary of two adjacent plates [Reid H.F. The California earthquake of April 18 1906. Vol. 2. The Mechanics of the earthquake. The Carnegie Inst. Washington, 1910]. The sharp compression of rocks, preceding their destruction, will lead to the generation of an electromagnetic pulse due to piezomagnetic mechanism. An alternative is a series of two or more pulses with a non- uniform structure of interblock cohesion. The results of the analysis can find application in the search and development of methods for forecasting earthquakes in seismic regions. The repeatability of electromagnetic precursors of repeated earthquakes gives the principal possibility of prompt notification (in a few minutes) of another earthquake. The work was carried out with the financial support of Programs No. 7 and No. 28 of the Presidium of the Russian Academy of Sciences and RFBR projects 16-05-00056 and 16-05-00631 and State order No. 0144-2014-00116. 115 NEW DATA ABOUT LOW MAGNITUDE SEISMICITY OF THE GAKKEL RIDGE ON THE DATA OF CONTINUOUS REGIONAL MONITORING Fedorenko I.V. N. Laverov Federal Center for Integrated Arctic Research, Arkhangelsk, Russia The Gakkel Ridge is the ultraslow spreading ridge situated in the Arctic region between Eurasian and North-American lithospheric plates. Its spreading rate decreases from 12.8 in the west to 6.5 mm/y in the east. According to geological and geophysical properties it is divided on three segments: the Western Volcanic Zone (WVZ, 7°W¨C3°E), the Sparsely Magmatic Zone (SMZ, 3°E¨C29°E) and the Eastern Volcanic Zone (EVZ, 29°E¨C128°E). Since 2011 several seismic observation points were set on the arctic islands, such as the Franz Joseph Land (ZFI, OMEGA) and the Severnaya Zemlya Archipelago (SVZ). This translates to representative ML magnitude was decreased from 3.6 to 2.8. The SVZ seismic station is main contributed in monitoring of the Eastern Volcanic Zone. Regional monitoring process is led using the NOES travel-time curve and mainly polar stations situated on the islands. Error ellipses were calculated for the range of earthquakes located during it. Events of the WVZ and the SMZ with ML>3 have lager location errors than produced by teleseismic ISC location. But in the EVZ values are comparable owing to SVZ seismic station. Most of earthquakes with ML<3 can be located only on base of three or four stations. The NOES travel-time curve is now the best for its location despite of large errors. Spectral-temporal analysis was made for the earthquakes registered in the period 01.12.2011¨C01.02.2015. The lower border f1 of events energy maximum is constant and equals about 2 Hz. The upper border f2 is different. As a result, earthquakes with various f2 values are registered in all zones. The WVZ has most low-frequency events which is consistent with its structure. The SMZ has wide range of f2 values. But most of all events are registered with maximum energy in range of 220 Hz. The EVZ also has a wide band of f2 values despite of presence of many volcanic centers. Spatio-temporal analysis was also made for the period 2011¨C2017. Single-link cluster analysis was the first used method. By this technique 4 seismic swarms were found in the WVZ and EVZ. The second used algorithm was created by Molchan and Dmitrieva and realized in the program of V.B. Smirnov for detection of aftershock sequences. As a result, no aftershock sequences were found. Thus opening of new seismic observation points large contributed in seismic monitoring of the Gakkel Ridge. But next improvement of observation system is need. This work was made with partial support of RFBR grant №18-05-70018. 116 SEISMICITY AND CRUSTAL STRUCTURE OF THE SOUTHERN CRIMEA AND ADJACENT NORTHERN BLACK SEA FROM LOCAL SEISMIC TOMOGRAPHY Gobarenko V.1, Yegorova T.2 1 Institute of Seismology and Geodynamics, Vernadskii Crimean Federal University, Crimea, Simferopol, prosp. akad. Vernadskogo 4, 295007 Russia 2 Institute of Geophysics, National Academy of Sciences of Ukraine, Kiev, Pr. Palladina 32, 03680 Ukraine [email protected], [email protected] The Greater Caucasus and the Crimea Mountains constitute a fold-and-thrust belt that formed at the southern margin of Eurasia as a result of Cenozoic collision between Eurasia and the Africa– ArabianPlate. The Main Caucasus Thrust (MCT), which marks the southern boundary of the Greater Caucasus orogen, can be traced westward along the northern margin of the Black Sea and southern Crimea and coincides with a zone of seismicity called the Crimea Seismic Zone (CSZ). The CSZ is characterized by earthquakes of M=3-5 with foci in the crust and uppermost mantle with abundant weak regional compression and transpression within the continental margin at the transition from continental crust to the “sub-oceanic” crust of the Black Sea. Weak seismicity was used to recover the velocity structure of the crust of southern Crimea Peninsula and adjacent northern Black Sea employing local seismic tomographic techniques. Events were recorded during 1970–2013 by nine stations on the Crimea peninsula (Crimea Seismic Network; CSN) and by one station (Anapa) on the Caucasus coast of the eastern Black Sea. Data for the tomographic inversion were relocated for the P- and S-wave arrivals at all permanent stations of CSN. Earthquake relocation was done via error minimisation starting with a 1-D reference velocity model based on seismic surveys (active and passive) in the study area. The new local tomographic results document significant P- and S-wave velocity heterogeneities in the depth range 10-30 km. Stable solutions have been obtained for depths of 15, 20 and 25 km. A distinctive feature of the crust of southern Crimea is its clear division on two domains: a western domain (Crimean Mountains) and an eastern one (Kerch-Taman zone). They are separated by a linear low-velocity zone of ~N-S strike (in the area between Sudak and Feodosiya) interpreted as a zone of crustal weakness that has been repeatedly reactivated. It could possibly be related to a collinear Proterozoic N-S trending fault zone in the Ukrainian Shield and/or a normal fault zone related to Early Cretaceous rifting and opening of the East Black Sea Basin. Interpretation of velocity anomalies suggests a complex 3-D crustal geometry that involved a change of underthrusting polarity in the western Crimea Mountains crust compared to eastern Crimea. This may be a reflection of structural inheritance and reactivation during compression of the same deeper structures that earlier controlled formation of the mid-Black Sea Ridge during Black Sea extension. 117 APPLICATION OF THE RECEIVER FUNCTION TECHNIQUE IN AREAS WITH A LOW-VELOCITY NEAR-SURFACE LAYER Goev A.G.1, Kosarev G.L.2, Sanina I.A.1 1 Institute of Geosphere Dynamics RAS, Moscow 2 Schmidt Institute of Physics of the Earth RAS, Moscow Low-velocity layers, or a zone of low velocities, are present almost at any point of the Earth's surface. It can be water, soil, ice, sedimentary layers of various nature, a destroyed bedrock, and perhaps something else not mentioned in this list. In our case, this can be a solid or loose or even semi-liquid rock with a velocity of P waves less than 4 -5 km / s. The depths of the relatively low velocities zone could vary first meters up to 10-20 km. The horizontal extent of the zone of low velocities is also important. It must be greater than or equal to the size of the first Fresnel zone when calculating the distance from the observation point. The receiver function method is used in those modifications where the velocity section of the low velocity zone or the velocity section of the earth's crust is determined, or the velocity section of the earth's crust plus the upper mantle to depths of about 300 km. The Eastern European Craton (EEC), and in particular the Moscow Syneclise, is an example of the almost ubiquitous spread of the near-surface zone of low velocities, or the sedimentary layer, separated from the crustal rocks of the Earth as a rule by a sharp boundary. An example of a region where, at most observation points, is no low-velocity zone, significant for the receiver function techniques is the Baltic Shield. The receiver functions obtained at the observation points with the low-velocity zone differ significantly from the receiver functions obtained at points where there is no sedimentary layer. The most noticeable feature in the waveform of the receiver function obtained in the low-velocity zone is the large amplitude of the converted PS wave from the sediment boundary-the foundation. In the Moscow Syneclise, the amplitude of this wave is twice that in comparison with the hypothetical situation of the absence of a sedimentary layer in this region. The record is an increase in the amplitude of a similar wave four times in Calcutta, located on a very powerful and low-speed sedimentary layer. Another important obstacle arises is interference between the single multiple wave P-Moho boundary-S and two or three- fold P2S and 2PS waves. This interference makes it almost impossible to visually determine a first multiple wave from the Moho boundary on the receiver function and greatly complicates the process of inversion of the receiver function in the velocity section. Given research goes in details of the formation of the receiver function from separate converted and multiple waves for the simplest models of the medium and analyzes the ways of overcoming the difficulties arising by the interference of single and multiple converted waves. Examples of inversion of receiver functions to velocity sections are given. This work was supported by the RFBR grant № 17-05-01099. 118 HIGH-SENSITIVITY SENSOR FOR CORRECTION OF INSTRUMENTAL THERMAL NOISE OF SEISMIC DEVICES Gravirov V.V. 1, 2, Kislov K.V. 1, Likhodeev D.V.2 1 Institute of Earthquake Prediction Theory and Mathematical Geophysics of the Russian Academy of Science (IEPT RAS), http://www.mitp.ru, Profsoyuznaya str. 84/32, Moscow 117997, Russia, Tel.: +7 (495) 333-4513 2 The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS), http://www.ifz.ru, B. Gruzinskaya,10, Moscow, 123242, Russia, Tel.: +7 (499) 766-26-56. One of the main noise-causing factors in long-period seismometry is temperature fluctuations of mechanical elements of devices, as well as temperature oscillations in their interior space. To reduce such noise it is possible to apply adaptive filtering of seismic signal with a support on elements temperature registration. However, to date, this way it was not possible to achieve significant results since there were no systems capable of recording temperature changes with sufficient accuracy. The developed high- sensitivity thermal sensor is capable of simultaneously monitoring the temperature at several of the most important points of any seismic device with an accuracy of about 0.005 degrees Celsius. PEMSDAS - PORTABLE EXPANDABLE MODULAR SEISMIC DATA ACQUISITION SYSTEM Gravirov V.V. 1, 2, Kislov K.V. 1, Sobisevich A.L. 2, Sobisevich L.E.2 1 Institute of Earthquake Prediction Theory and Mathematical Geophysics of the Russian Academy of Science (IEPT RAS), http://www.mitp.ru, Profsoyuznaya str. 84/32, Moscow 117997, Russia, Tel.: +7 (495) 333-4513 2 The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS), http://www.ifz.ru, B. Gruzinskaya,10, Moscow, 123242, Russia, Tel.: +7 (499) 766-26-56. One of the problems of seismic data registration is the need to provide a huge input dynamic range. We have developed a new small-size low-power data acquisition system based on a 24-bit analog-to-digital converter. The system does not require permanent connection to a PC and has a low cost. It is built on a modular-block principle that allows ones to flexibly change as the number of completely independent input data channels used and the type/model of the controller in accordance with the requirements of tasks being solved. A variant of constructing data acquisition system functioning on the base of a Raspberry Pi 3 microcomputer will be present as one of the possible configurations. This system will be especially useful for working as part of mobile seismic stations. 119 ATLAS OF THE AFTERSHOCKS: TO THE 150th ANNIVERSARY OF FUSAKICHI OMORI Guglielmi A.V.1, Zotov O.D.2, Zavyalov A.D.1 1 Institute of Physics of the Earth, RAS, Moscow, Russia 2 Borok Geophysical Observatory of Institute of Physics of the Earth, RAS, Borok Yaroslavl, Russia Our work is devoted to the memory of the outstanding Japanese scientist. In 1896, Fusakichi Omori discovered the law of the aftershocks evolution that bears his name. We propose a new approach to processing and analyzing the flow of aftershocks after the main shock of a strong earthquake. It is based on the nonlinear differential equation of aftershocks, which has the form of a shortened Riccati equation. The coefficient s in front of the quadratic term of the aftershock equation has the meaning of the deactivation factor of the earthquake source after the formation of the main discontinuity. For s = const, the aftershocks equation is completely equivalent to the hyperbolic law of Omori. A hypothesis has been put forward that the known deviations of the frequency of aftershocks from the hyperbolic law are due to the nonstationarity of the earthquake source after the formation of a main discontinuity in the continuity of rocks. The relaxation model of the source in which the deactivation coefficient s(t) depends on time is proposed. By using aftershocks equation, we posed and solved the inverse problem of physics of the earthquake source. This allowed us to determine the deactivation factor s(t) by using the observation of the frequency of aftershocks. We compiled the atlas of aftershocks after a series of strong earthquakes. The atlas contains a description of the parameters, the original sequence of aftershocks, and the function s(t) for each event. The analysis of the atlas showed a rich variety of the evolution forms of the earthquake source after the main shock. Our work was partially supported by the Program 28 of the Presidium of RAS, and RFBR project 18-05-00096. NEW MACROSEISMIC MANIFESTATIONS OF EARTHQUAKES IN THE VRANCH AREA ON THE TERRITORY OF UKRAINE Ilyenko V.A., Kushnir A.N. Institute of Geophysics by S.I.Subbotin name, National Academy of Science of Ukraine, Kiev In abstract the macro-seismic impact of seismic-active Vrancea Zone (Romania) on territory of Ukraine, on example of earthquake that occurred on September 23, 2016 at 23.11 GMT with magnitude of 5.6, is described. Location of seismic event is characterized by following geographic coordinates - 45.71°N, 26.59°E, and was located at distance of 8 km from Nerezhu commune that belongs to Vrancea county. A considerable part of the Ukrainian territory is under influence of the earthquakes, which take place in the Vrancea zone in Romania (area of the joint between the Eastern and Southern Carpathians). Focuses of the earthquakes, which are capable to become the reason of macroseismic manifestations on the territory of Ukraine, are located in the mantle at depths ranging from 80 to 190 km. Maximum magnitudes of earthquakes in this zone reached 7.6 points. At analyzing of quantity of earthquake in Vrancea zone in period of years 2000 - 2014, their cycle change with period of three years can be traced, except for years 2011-2012, when decrease of events quantity was not observed. In years 2000-2003 the quantity of earthquakes constantly increased, at this their peak 120 occurred in 2002. In general, since year 2000 at territory of Romania occurred approximately 13 earthquakes with magnitude of 5 and more. Due to the fact that one of the last earthquakes of September 23 was noticeable at a large part of Ukraine, for description and documentation purposes of its macro-seismic manifestations the questioning was conducted in accordance to SCS B.1.1-12:2014 of Ukraine. By means of Google form service the electronic questionnaire was created and distributed among respondents on territory of Ukraine, Romania and Moldova. In result of questioning 634 filled questionnaires from more than 35 cities and villages were received. In result of questioning and further processing of questioning results, two zones that are characterized by macroseismic manifestations of earthquake and correspond to five and four points by MSK-64 scale were distinguished. SOME REMARKS ON THE SEISMOMETRIC EXPERIMENTS TAKING INTO ACCOUNT THE THICKNESS OF THE FROZEN LAYER SOIL Kislov K.V.1, Gravirov V.V.1, 2 1 Institute of Earthquake Prediction Theory and Mathematical Geophysics of the Russian Academy of Science (IEPT RAS), http://www.mitp.ru, Profsoyuznaya str. 84/32, Moscow, 117997, Russia, Tel.: +7 (495) 333-4513 2 The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS), http://www.ifz.ru, B. Gruzinskaya,10, Moscow, 123242, Russia, Tel.: +7 (499) 766-26-56. Methodical studies of seismic wave propagation in shallow seismology remain relevant, since the accuracy of the observations depends on the correct interpretation of the data. The frozen soil layer thickness monitoring is necessary for many scientific objectives and applications. The soil frost level affects the accuracy of seismoacoustic methods in mining, seismoacoustic logging, engineering- geological surveys used for study the structure of geological formations, coal-seam fractures, assessment of the geological environment stress state, and shallow tomography. While the effect of soil temperature on the velocity of seismic waves has been investigated quite fully, the issue of waves attenuation depending on the thickness of the frozen layer remains a problem. The electrical properties of frozen soils have not been sufficiently measured yet. Hence, there is a need for creation of a measuring system, which, depending on the tasks will be able to produce different data set satisfying the necessary accuracy in the vertical, with the necessary discreteness in time, remotely and automaticaly. The ELFREEZMETER - electronic freezemeter has been developed for studying of influence of the frozen soil layer thickness on a seismic signal. But when ones working with almost any new system, naturally there are methodical difficulties, so we present some considerations on the representativeness of freezemeter data when they use in seismological experiments. 121 ON THE QUESTION OF THE ROTATIONAL SEISMOLOGY Kislov K.V.1, Gravirov V.V.1, 2 1 Institute of Earthquake Prediction Theory and Mathematical Geophysics Russian Academy of Science (IEPT RAS), http://www.mitp.ru, Profsoyuznaya str. 84/32, Moscow, 117997, Russia, Tel.: +7 (495) 333-4513 2 The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS), http://www.ifz.ru, B. Gruzinskaya,10, Moscow, 123242, Russia, Tel.: +7 (499) 766-26-56. No one has no doubt now the existence of rotational components of motion during an earthquake. It is a fact that interest in this potentially new field for seismology has risen during the last years. However, often even seismologists have questions: What does rotational seismology mean, what is magic for, what hardware it has, what it can give now and what can it achieve? Are measurements of rotational ground motions useful for seismology? Here we have decided to answer these questions concisely. Both the near-field and teleseismic rotational motions must be broken down and treated separately. It is caused not only weakening of movements at distance, and, consequently, the difference of instrumentation. To understand strong ground motions we must deploy extensive seismic instrumentation along active faults. Teleseismic registration so far also open more questions and create more difficulties than it purported to solve. SEISMICITY IN THE AREA OF NORTH SEA ROUTE Konechnaya Y.V.1, Fedorenko I.V.2 1 – United Geophysical Survey, Russian Academy of Sciences, Obninsk, Kaluga oblast, 249030, Russia 2 – N. Laverov Federal Center for Integrated Arctic Research, Arkhangelsk, 163000, Russia The North Sea Route (NSR) is an important transport route for Russia, whose security is the highest priority. A complex of observations is carried out on the territory such as meteorological and hydrological. Seismological data are not included in this system yet, although regional earthquakes and ice scrubs can significantly alter the spatial dynamics of the ice cover. At present time, gas and gas-condensate as well as oil and oil-condensate fields are discovered on the territory of the Barents and Kara Seas. In total, 58% of undiscovered reserves and 43 of 61 large fields are located in the Russian Arctic sector. In connection with the increase in hydrocarbon production, cargo transportation along the NSR is also developing. It is recognised that the area of the Northern Sea transport route in the Western part of the Russian Arctic is aseismic. According to data from international services within period 2000-2017, in the European sector of the Arctic about 9,300 earthquakes have been registered, some of which occur in the area of the NSR. We note an increase of seismic study in the area of the NSR after the opening of the seismic observation point on the Severnaya Zemlya archipelago in November 2016. More than 400 regional earthquakes and 122 16 local events were recorded during the first year of operation. The value of the local magnitude of earthquakes is in the range from 1.2 to 4.9. A feature of the Arctic seas is their long freezing and the formation of a huge ice cover. The maximum ice thickness is created in the area of the Severnaya Zemlya archipelago, in particular in the Vilkitski Strait through which passes NSR. It is significant that this area is characterized by modern seismicity. Earthquakes (both natural and caused by anthropogenic activities) can affect ice formation, and the formation of glaciers that prevent navigation results in the disruption of coastal pipelines. Currently, the representative level for Arkhangelsk seismic network for the given region is M=2.7. Weak seismic events allow us to expand our understanding of tectonic processes, which is very important for the Arctic regions, which are fragmentarily investigated, even to the point that even seismic zoning of different scales, there are "white spots", especially for shelf areas. This work was carried out by support of the Grant of the Young Scientists of Pomorie No. 05-2018-03a and partially by the Russian Foundation for basic research (№ 18-35-00021). POSSIBLE SHORT-TERM IONOSPHERIC PRECURSORS OF STRONG CRUSTAL EARTHQUAKES Korsunova L. P.1, Legenka A. D.1, Hegai V. V.1 1-Pushkov Institute of Terrestrial Magnetism, Ionosphere, and Radiowave Propagation, Russian Academy of Sciences (IZMIRAN), Troitsk, Moscow, Russia We have studied changes in the ionosphere prior to crustal earthquakes with magnitudes of М ≥ 6.5 based on the data from the ground-based stations of vertical ionospheric sounding in Japan for the period 1968– 2004 (32 cases). The data are analyzed based on hourly measurements of the virtual height and frequency parameters of the sporadic E layer and critical frequency of the regular F2 layer over the course of three days prior to the earthquakes provided that strong geomagnetic disturbances are absent. In the studied intervals of time before all earthquakes, anomalous changes were discovered both in the frequency parameters of the Es and F2 ionospheric layers and in the virtual height of the sporadic E layer. The changes were observed on the same day at stations spaced apart by several hundred kilometers. A high degree of correlation is found between the lead-time of these ionospheric anomalies preceding the seismic impact and the magnitude of the subsequent earthquakes. It is concluded that such ionospheric disturbances can be short-term ionospheric precursors of earthquakes. HETEROGENEITIES OF THE EARTH'S INNER CORE BOUNDARY FROM DIFFERENTIAL MEASUREMENTS OF PKIKP AND PCP SEISMIC PHASES Dmitry Krasnoshchekov, Vladimir Ovtchinnikov Institute of Dynamics of Geospheres, Russian Academy of Sciences, Russia 119334 Moscow Leninsky pr. 38 korp. The Earth's crystalline inner core (IC) solidifies from the liquid Fe alloy of the outer core (OC), which releases latent heat and light elements sustaining the geodynamo. Variability in solidification regime at 123 the inner core boundary (ICB) may result in compositional and thermal multi-scale mosaic of the IC surface and dissimilarity of its hemispheres. Both the mosaic and hemisphericity are poorly constrained, not least due to a lack of available sampling by short-period reflected waves. Measured amplitude ratio of seismic phases of PKiKP and PcP reflected, respectively, off the inner and outer boundary of the liquid core, yields direct estimate of the ICB density jump. This parameter is capable of constraining the inner– outer core compositional difference and latent energy release, but is not well known (0.2–1.2 g/cub. cm), and its distribution is obscure. Travel time measurements of PKiKP and PcP waveforms can be useful in terms of getting an insight into fine structure of ICB and its topography. We analyse a new representative sample of pre-critical PKiKP/PcP differential travel times and amplitude ratios that probe the core’s spots under Southeastern Asia and South America. We observe a statistically significant systematic bias between the measurements collected in western and eastern hemispheres, and carefully examine its origin. Separating the effects of core-mantle boundary and ICB on the measured differentials is particularly challenging and we note that a whole class of physically valid models involving D’’ heterogeneities and lateral variation in lower mantle attenuation can be employed to account for the observed hemisphericity. However, we find that variance in PKiKP-PcP differential travel times measured above the epicentral distance of 16 degrees is essentially due to mantle heterogeneities. Analysis of data below this distance indicates the ICB density jump under Southeastern Asia can be about 0.3 g/cub. cm, which is three times as small as under South America where also the thickness of the above liquid core can be by 1-3 km in excess of the one in the East. The findings preclude neither IC hemispherical asymmetry (whereby crystallization dominates in the West and melting in the East) nor patchy IC surface, but provide an improved and robust estimate of the ICB density jump in two probed locations. RADIAL ANISOTROPY OF THE EUROPEAN UPPER MANTLE FROM RECORDS OF EARTHQUAKES AND SEISMIC NOISE E.L.Lyskova, T.Yu.Koroleva, T.B.Yanovskaya St. Petersburg State University Radial anisotropy of the upper part of the Earth results in impossibility to satisfy dispersion curves of Rayleigh and Love waves by a unique S-wave velocity-depth curve. Rayleigh wave dispersion curves correspond to SV-wave velocities, whereas Love wave curves are responsible for SH velocities. Anisotropy coefficient is defined as a relative difference between SH and SV velocities. Analysis of Rayleigh and Love wave dispersion curves along oceanic paths has shown that in the oceanic upper mantle Vsh>Vsv up to ~200 km. This inference was obtained easily because the oceanic crust and upper mantle are almost homogeneous laterally. However the data on anisotropy under continental regions are rather discrepant due to considerable lateral heterogeneity of the continental crust and upper mantle. To estimate the anisotropy coefficient under continents it is necessary to apply the tomographic inversion separately to Love and Rayleigh wave dispersion curves, and to compare the corresponding S-wave velocity-depth curves in the same points. However, this approach leads to considerable errors, because velocity values obtained from the tomography are not local: they are averaged over rather spacious areas that are usually different for Love and Rayleigh waves. To overcome this drawback we applied surface wave tomography directly to anisotropy coefficient for each wave path rather than to dispersion curves separately. The dispersion curves are determined in the period range 10–100 s from records of earthquakes and from cross-correlation functions of seismic noise between pairs of seismological stations. For each path the dispersion curves of Rayleigh and Love waves are inverted to the SV and SH velocity-depth curves. Then path anisotropy coefficients are estimated from these curves as averaged in several depth intervals: in the crust and in three 30–km intervals in the upper mantle. 124 Finally tomographic inversion was applied to the path anisotropy coefficients in the selected depth intervals. The most reliable results were obtained for the two upper layers in the mantle. It was found that in central Europe the anisotropy coefficient is close to zero and maybe even slightly negative, whereas at the periphery of the study area (Baltic, Mediterranean, Black sea) it is positive and close to that for the oceanic regions (3–4%). This study was supported by the RFBR research grant No. 17–05–00522. SOFTWARE SERVICE «SEISMOLOGY ONLINE» Mikhailova Yana1, Morozov Alexey2 FSIoS FRCCSoA RAoS 1 [email protected], 2 [email protected] “Online Seismology” Software was developed and applied for the assessment of seismic hazards of Arctic archipelagoes of Svalbard, Franz Josef Land and Novaya Zemlya. Online Seismology software is designed to be accessed online by multiple users through a web-browser. This software is based on a consolidated earthquake catalogue covering the period from the early 20th century to 2018. The following sources contributed to the compilation of the catalogue: Seismic catalogue of the Arkhangelsk Seismic Network; Seismic catalogue of the field station that operated on the island of Alexandra Land of Franz Josef Land from 1969 to 1970 (Avetisov, 1971); Specialized earthquake catalogue of Northern Eurasia (SECNE, Kondorskaya, Ulomov (Special¡K, 1996, Ulomov at al. 1996)); International Seismological Center catalogue (www.isc.ac.uk) that compiles data from various seismological centers; Catalogue of the NORSAR seismological agency (www.norsardata.no); Catalogue of the Norwegian National Seismic Network (www.geo.uib.no/seismo/). The catalogue is updated through automatic /semiautomatic import of data from the data sources. For ease of data analysis and selection, this software service allows to maintain a list of user-defined geographical zones. Boundaries of such geographical zones can be set both graphically and by specifying the nodes manually. The data output option enables the user to view a list of seismic events or save it to a file (supports formats - MS Excel, pdf, etc.). A model for conversion of all types of magnitudes calculated by various seismological centers to the unified magnitude was developed as part of the consolidated catalogue compilation process. This software tool is designed to calculate seismic activity and tremor rate. Events selected from the consolidated earthquake catalogue as well as seismic activity and tremor rate calculation results can be visualized with ArcGis in 3D scenes and 2D maps. 125 GEODYNAMICS OF THE EAST-EUROPEAN CRATON BASED ON UP-TO- DATE GNSS DATA A. V. Mokhnatkin1, V. L. Gorshkov1, N. V. Scherbakova1, B. A. Assinovskaya2 1 CAO RAS (Pulkovo Observatory) 2 FRC RAS (Federal Research Center of RAS), Geophysical Survey, Pulkovo Seismic Station The new database of GNSS velocities for the stations on the East European Craton (EEC) has been recently compiled using various data sources. Present database contains data for more than 300 stations having observations which last two years and more, including plenty of Russian stations. These data have free access and can be used for the further geodynamics research of the region. The dense network of gathered GNSS stations contributes the kinematic study of EEC, especially for surroundings of the Gulf of Finland. The EEC basement is formed by the combination of numerous geological structures which have different age, heterogeneous composition and different history of geological development. In particular, the basement of EEC has two crystalline shields: Baltic (BS) and Ukrainian, separated by the Russian Plate (RP), having powerful sedimentary cover. The western part of RP has various extensional structures, that correlates with the strain data provided by GNSS measurements. Angular velocities of BS and RP solid-body rotation were evaluated. Since the NW part of Europe is subject of the post-glacial uplift (PGU), the corresponding model corrections were used for the velocity field assessment. The difference in rotation of these blocks is statistically insignificant (BS: 0.257+-0.002, RP: 0.254+-0.003 deg/Ma), whereas deformation field modelled for the especially dense GNSS net surrounding the Gulf of Finland region shows a weak (2-3 nanostrein/year) compression in the direction from NW to SE. The field of vertical velocities without PGU elimination has a drastic shift from elevation to depression at the border of two blocks. The horizontal deformation field at the junction zone of RP and BS reflects the structure of the basement. There are stand out the Novgorod granitoid intrusion at the centre and numerous aulacogens where the horizontal compression changes its direction. This fact is evidence of the current geodynamic activity of the region, which can be realized both in the form of weak earthquakes and plastic deformations. There were already several seismic events caused by faulting at Paldiski-Pskov seismogenic zone, that adjacent to the Western part of the region, during 2018. Present conclusions correspond with data on negative vertical deformations which prevail, despite the fact that this area has to be exposed to post-glacial rebound. NATURAL AND TECHNOGENIC SEISMIC AND GEODYNAMIC ACTIVITY OF THE SOUTHERN URALS Nesterenko M. Yu. Orenburg Scientific Center of Ural branch of Russian Academy of Sciences Monitoring and investigation of the geodynamic state performed by the Department of Geoecology of the Orenburg Scientific Center of the Ural Branch of the Russian Academy of Sciences in the Orenburg Pre- Urals made it possible to obtain conclusions about the level of seismic activity within the platform part of the Orenburg region. In addition to natural seismicity, technogenic seismicity becomes an important factor, the role of which increases with the increase in oil and gas production at the exploited fields. The 126 geodynamics of the Southern Urals is poorly understood, because the region is located on a platform, that are traditionally called geodynamically inactive and weakly seismic. The focus was on active mountain- folded structures. However, in recent years, according to a number of seismologists and geologists, interest in studying the geodynamics of platform areas has increased significantly after it was discovered that the platforms are quite mobile, especially near folded areas. Natural seismic activity caused by a advances crustal blocks relative to each other according to the block- layered structure of the crust. However, triggered seismicity also gets discharged through existing mobile zones. In conditions of natural geo-and hydro-geodynamic processes, block-fault structure of the earth's crust, intensive oil and gas production in large oil and gas bearing areas disrupts the natural, including geological, environment, significantly transforms hydrodynamic and geodynamic processes in the earth's crust to depths of up to ten kilometers or more on areas up to several thousand square kilometers. Conditions are created for the emergence of a number of environmental problems that significantly affect the development of nature and the livelihoods of the population in the region. Complex researches of geodynamic and seismic activity in the Southern Urals revealed and explore the laws of formation of the modern tectonic processes in natural and anthropogenically modified conditions. The layered-block structure of the earth's crust leads to an inhomogeneous distribution of stresses and to their concentration in the contact points of the blocks. The main influence on the natural stress-strain state of the Earth's interior is exerted by gravitational forces and tectonic processes. The developed methodology for monitoring the geodynamic state of the geological environment using global satellite navigation systems and seismic stations is based on an integrated approach that takes into account the interaction of geological structures, dynamics of the hydrogeosystem, extraction of minerals, and the stress-strain state of the earth's crust. Comparative analysis of the geological structure, fault system, the dynamics of groundwater, stress-strain state of the earth's crust and the seismicity of the region allowed to regionalize the territory of geodynamic and seismic activity. ANALYSIS OF THE SPATIAL DISTRIBUTION OF THE EARTHQUAKE FOCAL MECHANISMS IN THE KURIL-OKHOTSK REGION Polets A.Yu. Institute of Marine Geology and Geophysics Far Eastern Branch Russian Academy of Sciences One of the main parameters which characterize the seismic event is the earthquake focal mechanism. A spatial analysis of the earthquake focal mechanisms in the Kuril-Okhotsk region was carried out on the basis of the Global CMT Project data. A new catalog was created for the region of 43¨C600 N and 139¨C1650 E. The observation period was from 1976 to 2018. The catalog included 1822 seismic events with moment magnitudes from 4.7 to 8.3. The maximum depth of events is 690 km; the most representative range of earthquake magnitudes is from 5.0 to 6.0; the major part of the earthquakes for which were determined the focal mechanisms are located at depths of 0-60 km according to the initial seismological data analysis. In order to analyze the types of earthquake focal mechanisms we used the classification, which is usually applied for selecting the geodynamic regimes of deformation during the state of stress analysis [Rebetsky, 2007]. The main types of earthquake focal mechanisms are reverse, strike-slip fault and normal fault. The intermediate types are the combination of strike-slip with revers or with normal faults, and the shift along the subvertal nodal plane. Analysis of the catalog shows that it contained 1010 (55.4%) reverse events, 157 (8.6%) normal faults, 97 (5.3%) strike-slip faults, 370 (20.3%) strike-slip with revers and 188 (10.3%) strike-slip with normal 127 faults. The analysis of the earthquake focal mechanisms within the 11 depth levels has shown that reverse is a prevalent type for depth 0-30 km (452 events (65 %)) and for 30-60 km (488 events (75%)). Reverse (48 events (34%)) and reverse with strike slip (52 ñîáûòèÿ 37%) are typical at depths of 90-120. Strike- slip with revers or strike-slip with normal faults are common for the depth 120-700 km. Thus the prevalent areas of different types of Kuril-Okhotsk earthquake focal mechanism are determined for different depth levels. The reported study was partially supported by the Grant of the President of the Russian Federation, research project MK-2421.2017.5 and by RFBR, research project No.17-05-01251 a. FEATURES OF THE TECTONIC STRESS FIELD IN THE OKHOTSK SEA AND JAPANESE REGIONS Polets A.Yu. Institute of Marine Geology and Geophysics Far Eastern Branch Russian Academy of Sciences The Kurile-Okhotsk and Japanese regions are characterized by a high level of seismicity. Earthquakes with a moment magnitude over 8.0 may occur here. The Kuril-Okhotsk region is located at the junction of three major lithospheric plates – the Eurasian, Pacific and North American (the Okhotsk microplate). The Japanese region is located at the junction of four lithospheric plates - the Eurasian, Pacific, North American and Philippine Sea plate. The high seismicity of the studied regions is due to the intensive geodynamic interaction of the lithospheric plates. The method of cataclastic analysis of discontinuous displacements was used to reconstruct the modern state of stress parameters in the investigated regions. The worked catalogs were created on the basis of Global CMT Project data. The seismic data processing was carried out in the long-period reconstruction mode at the grid nodes 0.50x0.50 for different depth levels. The number of events in a homogeneous sample set of earthquake focus mechanisms were from 6 to 10. The orientation of the principal stress axes and the Lode-Nadai coefficient or stress ratio, which characterizes the shape of the stress ellipsoid, are evaluated during the first stage of the MCA [Rebetsky, 1996, 1999]. The extreme values of the Lode-Nadai coefficient (+1 and -1) correspond to the states of uniaxial compression and extension, and the zero value for pure shear. The main type of the stress tensor for the studied regions is the pure shear and its combinations with uniaxial compression. A characteristic feature of the stress field of the investigated regions is the orientation of the principal stress axes. In the Kuril-Okhotsk region, the projections of the principal stress axes of maximum deviatoric compression (σ3) and extension (σ1) oriented almost orthogonally to the Kuril trench. The axis of maximum compression dips under the oceanic plate and the axes of maximum extension dips under the continental plate. In the Japanese region, the principle stress axes also oriented almost orthogonally to the axis of the oceanic trench, with the exception of the area along the Nankai segment of the Philippine Sea plate. Data on the orientation of the principal stress axes and the vector to the zenith made it possible to make zoning by the types of the geodynamic regime. In the Kuril-Okhotsk and in the Japanese regions the prevalent geodynamic regime is horizontal compression but it changes with depth. The most stable prevalent geodynamic regime is at depth of 30–60 km for both regions. In the Japanese region, there are large areas of horizontal extension to the east of the oceanic trench. It should be added that this regime was existed here before the 2011 Tohoku earthquake The horizontal shift is along the Nankai trench zone. The trajectories of the underthrust shear stresses determine the direction of action on the bottom of the earth’s crust from the upper mantle. Such orientation of the principal stress axes is common for the subduction zones and it determines as the active force the underthrust shear stresses. The underthrust 128 shear stresses, which acting normally on a horizontal plane pointed towards the center of the earth, determines the corresponding type of motion of the subcrustal lithospheric substance as active force of the present stage of the tectonic process. The stable orientation of the underthrust shear stresses is observed at the depth 0-300 km, but with increasing depth (300–700 km) the orientation of theses axes sharply changes to the opposite direction. Zoning of the intensity of the dilatancy process was carried out based on the results of the stress inversion. In the Kuril-Okhotsk region, the most intensive dilatancy processes are now occurring in the earth's crust near Kamchatka and along the southern part of the Kuril Island. Low rates of dilatancy loosening can be observed in the central part of the Kuril Island and near Hokkaido Island. In the Japanese region, extensive areas with an increased rate of dilatancy are present in the earth's crust east of the northern part of Honshu Island, south of the Tokyo Bay and Okinawa Island. The rate of dilatancy is generally low in the earth crust of the Honshu Island. The reported study was partially supported by the Grant of the President of the Russian Federation, research project MK-2421.2017.5 and by RFBR, research project No.17-05-01251 a. SPLITTING OF EARTH'S FUNDAMENTAL SPHEROIDAL MODE 0S2 IN GEOMAGNETIC VARIATIONS Riabova S.A., Spivak A.A. Institute of Geospheres Dynamics of Russian Academy of Science 4. There are two separate types of free oscillations of an Earth - spheroidal (S) and torsional (T) (sometimes called toroidal). Torsional oscillations have tangential but no radial displacements. Since the dilatation is zero, torsional oscillations cause no disturbances in density and hence no changes in the gravitational field. Thus any instruments designed to measure small fluctuations in gravity cannot record torsional oscillations. In spheroidal vibrations, the displacements have, in general, both radial and horizontal components. The lowest frequency mode of the oscillations is the fundamental spheroidal mode 0S2 with five components that has a period of about 54 min. It seems promising to use geophysical fields, for example, the geomagnetic field as an indicator of the Earth's free oscillations. As the initial data we used the results of recording the Earth's magnetic field at the Geophysical observatory "Mikhnevo" of the Institute of Geospheres Dynamics (54.959º N, 37.766º E), carried out in the period 2010 - 2015. Recording geomagnetic variations during strong earthquakes allow us to detect modes 0S2. In periods of 15 days after major earthquakes, in the absence of strong magnetic disturbances, it is possible to distinguish the fine structure of the basic spheroidal mode of the earth 0S2 in the geomagnetic variations. The estimated singlet frequencies of 0S2 are good agreement with theoretical ones computed for the Earth model 1066A. This indicates that the Earth's magnetic field is very sensitive to mechanical processes occurring in the Earth. 129 DEEP VELOCITY SRTUCTURE OF THE ARCTIC REGION FROM RAYLEIGH WAVE DISPERSION DATA Alena Seredkina Institute of the Earth’s crust SB RAS, Irkutsk, Russia We study deep velocity structure of the poorly investigated Arctic region (>60° N) on the basis of surface wave data. A representative dataset of Rayleigh wave group velocity dispersion curves (1555 seismic paths) in the period range from 10 to 250 s was collected using a frequency-time analysis procedure. A 2D tomography technique developed for spherical surface without the sphere-to-plane transformation was implemented to image the distributions of the group velocities at different periods. Totally, we calculated 18 maps for different periods and estimated their lateral resolution. Then, we constructed local dispersion curves of Rayleigh waves and inverted them to S-wave velocity sections up to the depth of 500 km. The obtained S-wave velocity model of the upper mantle was imaged in the form of horizontal distributions of velocity variations at different depths and 2D velocity sections along the profiles crossing the main tectonic units of the study area. Our results show some general trends in distribution of large-scale lateral inhomogeneities which appear as zones of high velocity gradients at the boundaries of tectonic units and local velocity minimums and maximums. The highest group and S-wave velocities are observed under the Canadian and Baltic Shields. The Siberian and East European Platforms are also characterized by high velocities. The lowest velocities are observed under the fold belts at the north-east of Eurasia and Alaska and under the Bering Sea basin. We found evidences of the mantle plumes under Iceland and Jan Mayen Islands represented by velocity minimums. The spreading Gakkel Ridge is manifested as low velocity zone which widens at the Laptev Sea shelf. Thus, the revealed velocity anomalies are correlated with the positions of the main tectonic structures of the study area. The results obtained are of great value for further development of reliable geodynamical models of the Arctic region. This work was supported by the grant of the Russian Science Foundation, project No 17¨C77¨C10037. SUPERDEEP DRILLING AND ITS EFFECT ON THE SEISMIC MODELS OF THE FENNOSCANDIAN SHIELD Sharov N.V. Institute of Geology, Karelian Research Centre, RAS, Petrozavodsk, Russia An attempt to interpret the origin of seismic boundaries in the crystalline crust from deep drilling record and available geological and geophysical data on the drilling area was made. Deep drilling was conducted in several regions of the Fennoscandian Shield: Kola, Russia (SG-3), to a depth of 12262 m (1970-1990); Gravberg (GR) and Stenberg-I, Central Sweden, to a depth of 6337 m (1986-1987); and 6529 m (1991- 1992); Outokumpu (OU), SE Finland, to a depth of 2516 m (2004- 2005); Pogranichnaya (P-1), Sredny Peninsula, Murmansk Region, Russia, to a depth of 5200 m (2004-2006); and Onega, Central Karelia, Russia (ON), to a depth of 3537 m (2007-2008). The results obtained were analyzed. They show considerable discrepancies between forecast seismic-geological models and the actual structure of the upper portion of the continental crust. Deep drilling has proved that heterogeneities in the upper portion of the crystalline crust, indicated by geophysical data, are due to changes in the composition and physical condition of deep-seated rocks. Therefore, even approximate rock composition cannot be ultimately estimated from elastic wave velocity values alone. It showed the real pattern and origin of lowered elastic wave velocity zones in the upper portion of the crust and did not show that layers become more 130 homogeneous with depth. The origin of intracrustal seismic boundaries could be affected by various factors such as variations in mineralogical composition, structural and textural differences between the rocks and a thermodynamic setting [1]. Deep drilling provided direct data on the composition and structure of the upper portion of the crystalline crust to a depth of 12 km. They showed that we do not know anything about the continental crust and made us considerably revise our earlier concepts. Deep drilling proved that the heterogeneities, identified by geophysical methods in the upper portion of the crystalline crust, are the result of changes in the composition and physical condition of deep-seated rocks. Therefore, even the approximate composition of the rocks cannot be ultimately determined from elastic wave velocity values alone. The results of the geophysical studies, conducted as part of deep drilling on the Fennoscandian Shield, make scientists re-interpret relevant geological and geophysical data. The mineralogical composition and petrophysical characteristics of rocks can be assessed only by deep drilling of the crystalline crust. The objective geological-geophysical sequence of the upper portion of the earth crust can thus be constructed. References 1. Sharov N.V. Lithosphere of North Europe based on seismic data // Petrozavodsk KarRC, RAS. 2017. 173 p. SELF-SIMILARITY ANALYSIS OF EARTHQUAKES AND ACTIVE FAULTS WITHIN THE SIKHOTE-ALIN OROGENIC BELT AND NEIGHBORING AREAS Zakharov V.S. 1,3*, Didenko A. N. 2,4, Gil’manova G.Z. 2, Merkulova T.V. 2 1 – Moscow State University, Geological Faculty, Moscow, 119991 Russia 2 – Kosygin Institute of Tectonics and Geophysics, Far East Branch, Russian Academy of Sciences, ul. Kim Yu Chena 65, Khabarovsk, 680000 Russia 3 – Dubna University, ul. Universitetskaya 19, Dubna, Moscow region, 141982 Russia 4 – Pacific National University, ul. Tikhookeanskaya 136, Khabarovsk, 680042 Russia A comprehensive analysis of self-similarity characteristics of earthquakes and active faults within the Sikhote-Alin orogenic belt and adjacent areas has been carried out. The main features of seismicity are found to be determined by crustal earthquakes. Variations in density and fractal dimension De of earthquake epicenters in the region show that the most active sections of the earth's crust are in the Kharpi-Kursk-Priamur zone, the northern Bureya Massif, and the Mongol-Okhotsk fold system. Analysis of the parameter b of the Gutenberg-Richter law suggests that its highest values, on the whole, correspond to the areas of the highest seismic activity which is in the northern part of the Bureya massif and, to a lesser extent, the Mongol-Okhotsk system. Higher values of fractal dimension of the fault network Df are found to correspond to fold systems (Sikhote-Alin and Mongol-Okhotsk) and lower values to basins and troughs (Sredneamursky basin and to a lesser extent Uda and Torom basins). A correlation made between findings of fractal analysis of the fault network and data on the current stress-strain state, established by different methods employed in works of other authors, shows that higher values of Df occur in areas of present-day intense compression. A good correspondence between the parameter b field and the field of Df indicates a general consistency 131 of the self-similar distribution of the earthquake magnitude (and hence energy) and the fractal distribution of fault dimensions. Our results demonstrate that self-similarity parameters are an important quantitative characteristic in seismotectonics and can be used for neotectonic and geodynamic analysis. This study was supported by the Russian Science Foundation (project no. 16-17-00015). The research is carried out using the equipment of the shared research facilities of HPC computing resources at Lomonosov Moscow State University. ON THE SPATIAL-TEMPORAL STRUCTURE OF AFTERSHOCK SEQUENCES Zotov O.D.1, Zavyalov A.D.2, Klain B.I.1 1Borok Geophysical Observatory, Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Borok, Yaroslavl region, Russia 2Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia The work presents results of statistical analysis of the spatial-temporal distribution of strong aftershocks. Data from the world catalog of earthquakes NEIC USGS from 1973 to 2014 (https://www.usgs.gov) and from the regional earthquakes catalog of Northern California from 1968 to 2007 (http://www.ncedc.org) were used. Short time intervals were considered - no more than 10 hours before and after main shock and distance from the epicenter of the main shock - up to 5 degrees. The distribution of the aftershocks number in the time-distance coordinates from the main shock was investigated. The method of superposed epochs was used. The main shocks performed the function of reference mark for the synchronization of sequences of repeated shocks. To each main shock was attributed the conventional time equal to zero, and its epicenter coincided with the origin of coordinates. The main shocks with magnitude Mms 7.5 and aftershocks with 6 Mas 132 STP. SOLAR-TERRESTRIAL PHYSICS Conveners - Dr. N.V.Zolotova, Dr. A.V.Divin Space climate and space weather Magnetospheric phenomena Ionosphere and upper atmosphere physics EMPIRICAL MAGNETOSPHERIC MODELS FOR SIR- AND CME-DRIVEN MAGNETIC STORMS Andreeva V. A.1, Tsyganenko N. A.1 1 – Saint Petersburg State University (SPbU), Saint Petersburg, Russia While in general the solar wind has an extremely variable structure, during geomagnetic disturbances it tends to arrive in the form of characteristic sequences lasting from tens of hours to days. The most important magnetic storm drivers are the coronal mass ejections (CMEs) and the slow-fast stream interaction regions (SIRs). Despite the fact that the CME- and SIR-driven storms are accompanied with largely different forms of geomagnetic activity, previous data-based magnetic field models did not distinguish between these types of the solar wind driving. In the present work we retained the basic structure of the TA15 model [1], but fitted it to three different data samples corresponding to (1) SIR- driven magnetic storms, (2) CME-driven storms preceded with a shock ahead of the CME, and (3) CME- driven storms without such shocks. The storm-time dynamics of the model current systems has been studied using the advanced parametrization method developed in TS05 [2]. The essence of the approach was to parameterize the model with dynamical variables Wi, calculated on the basis of concurrent solar wind characteristics and their previous history. The employed database included observations of THEMIS, Polar, Cluster, Geotail, and Van Allen Probes missions during 156 magnetic storms in 1997- 2016. 1. Tsyganenko, N. A., Andreeva, V. A. // JGR-A 2015. V. 120. doi:10.1002/2015JA021641. 2. Tsyganenko, N. A., Sitnov, M. I. // JGR-A 2005. V. 110. doi:10.1029/2004JA010798 133 DEPRESSION OF THE TOTAL FLUX OF SOLAR ELECTROMAGNETIC RADIATION DURING THE GENERATION OF RELATIVISTIC PROTONS OF SOLAR COSMIC RAYS Avakyan S.V. 1, Nicvol’skii G.A. 2 1- All-Russian Scientific Centre “S.I. Vavilov State Optical- Institute”, 199034, Russia 2- Saint-Petersburg State University, Russia [email protected], [email protected] The circumstances of the discovery of a new physical phenomenon in the atmosphere of the Sun are presented: a depression of the total flux of Total Solar Irradiance before and during the generation of protons of relativistic energies (more than 500 MeV) of solar cosmic rays. Such events result in the appearance of secondary cosmic particles reaching the earth's surface at sea level and are classified as Ground Level Events / Ground Level Enhancements (GLE). On average, they are observed on Earth once a year, and their 70-year recording by ground-based neutron monitors is now in continuous operation. Prior to our work, this anticorrelation of the values of the TSI and GLE of SCR flows was unknown, although it is found to be more than 80% probable. It should also be noted that the drop in the TSI value is higher (up to 0.3%) in comparison with other events. The discovery of the phenomenon is of fundamental importance for the physics of the solar atmosphere, as well as sun-like stars. It is also important for solving practical issues of extra-geomagnetospheric astronautics, especially for ensuring the safety of manned spaceflight, for example, to Mars and potentially dangerous asteroids. The use of patrol regimes to control the level of TSI appears to be the basis for an advance forecast of the maximum radiation hazard in the exploitation of the Moon. We associate the physics of the open phenomenon with the development of the flare activity of the Sun, when conditions are met for the appearance of high-temperature (more than 25-30 MK) flares in the x-ray range, often with the location of the outbreak at the limb. In these cases: - for the acceleration of protons in the solar atmosphere, the advantages of a lower density of the medium (consequently, with a decrease of emission measure of electromagnetic radiation) are realized; - the exit to the near-solar space of accelerated relativistic protons is facilitated along such a thin plasma layer near the limb, due to the lower absorption losses. The report suggests ways to further study the detected phenomenon, including in the interests of its advance forecast for the safety of future interplanetary space manned flight activities 134 HOW DOES THE GEOCOSMOS CONTROL THE BIOSPHERE? FORMATION OF ASSOCIATES IN HIGH DELUTED WATER BIOSOLUTIONS UNDER THE INFLUENCE OF THE MICROWAVE FLUX FROM THE IONOSPHERE Avakyan S.V. 1, Baranova L.A. 2 1 - All-Russian Scientific Centre “S.I. Vavilov State Optical- Institute”, 199034, Russia 2- Ioffe Institute, 194026, Russia [email protected], [email protected] The purpose of our study is to consider the influence of the electromagnetic field of the environment on the change in the structure of aqueous biosolutions, taking into account the processes of physics of electron-molecular collisions. Until now, the assumption of A.N. Szent-Giorgui, the Nobel laureate on physiology that: “Probably, biology did not already succeeded in understanding the main functions because it concentrated its attention only on matter in form of particles, distinguished it from the two matrices: water and electromagnetic field” remains relevant. In our approach, both water of organism and electromagnetic (microwaves) radiation of environment is taken into account in the framework of developed supramolecular physics. Supramolecular physics describes a processes developing outside the molecules (atomic-molecular cores) in whose evolution to the complex forms (clusters, associates) electromagnetic radiation of external origin absorbed by exited Rydberg components of molecular complex takes part. Due to increasing value of orbital momentum of Rydberg electrons the stability of the complex grows because probability for forming a stable neutral cluster becomes higher as the electron more seldom penetrates into the ion core. The report presents for the first time the following results:- it is determined that the electromagnetic radiation absorbed in the liquid medium, which causes in it an increase in the number and size of clusters with the participation of water molecules, can simultaneously lead to the induced emission of these clusters at the same frequency. This is accomplished by absorption of microwave quanta by Rydberg states, even with a greater probability than emission in spontaneous transitions. The induced radiation is up to half of the total flux of quanta of external electromagnetic radiation absorbed by the liquid medium and is capable of participating in further acts of increasing the growth of clusters involving water molecules; - attention is paid to the importance of the presence of Rydberg-excited levels in such important biological materials as DNA, red blood cells, oligopeptides, glycopeptides, chloroplasts etc. [1]. This can lead to a nonradiative transfer of potential energy stored in water clusters to biocomponents in impacts of the second kind [2]; - the explanation of the effect of "large dilutions" - when in associates of some biologically active substances associates formation is intensified [3] with water addition to the minimum concentrations (10- 15 - 10-18) M, taking into account the effect of microwave radiation of the ionosphere on the probability of associates formation. 1. Robin M., Higher excited states of polyatomic molecules, Academic Press, 1985, V. 3. 2. Frish S.E., Optical atomic spectra, Physmatgis, 1963. 3. Konovalov A.I., Formation of nanoscale molecular ensembles in high diluted water solutions // Herald of RAS, 2013, 83, N6. 135 HOW DOES THE GEOCOSMOS CONTROL THE BIOSPHERE?2. DNA, IONOSPHERIC MICROWAVES AND WATER Avakyan S.V. 1, Baranova L.A. 2 1-All-Russian Scientific Centre “S.I. Vavilov State Optical- Institute”, 199034, Russia 2- Ioffe Institute, 194026, Russia [email protected], [email protected] The purpose of the work was to create model representations for describing the nature of the features known in modern biophysics in the manifestation of the associative properties of highly dilute biologically active solutions (see [1]), including under magnetic (metal) shielding. The task of the paper was to show that the phenomena observed in the works of L. Montagnier, the Nobel laureate on physiology, 2008, with the behavior of viruses (including the Human Imunodeficiency Virus) and some bacteria [2] may be related to the impact of microwave fluxes in the first a queue of ionospheric origin, on structure formation involving water molecules. A well-known mechanism of associates formation is taking into account the high affinity for the proton in water molecules. The approach developed in the Vavilov Institute is used within the framework of supramolecular physics of over-molecular structures with participation of the neutralizing electrons in Rydberg states [3, 4]. In the framework of theoretical physics [2] consideration of the existence of Coherence Domains, based on Quantum Field Theory, can be regarded as an analogue of our approach. As for water in [2] it is considered the excited state lying at 12.06 eV, which in our model representation refers to the Rydberg state of the water molecule. The report presents for the first time the following results: - phenomena in highly diluted water biosolutions, including DNA [2], are associated with the effect of the constantly existing flux of microwave radiation from the terrestrial ionosphere on the structuring of water molecules. In laboratory experiments [1, 2], it was not taken into account that artificial magnetic shielding by 1 mm thick layer of mu-metal absorbs also all microwaves fluxes of the environment [3, 4]; - the flux of microwaves of the ionospheric nature is modulated at Schumann frequencies in a ground- ionosphere resonator, primarily at a frequency of about 8 Hz. Its magnitude sporadically increases during periods of flares on the Sun and geomagnetic storms. It is shown that with calm solar-geomagnetic activity, the fluence of the background ionospheric flux of microwaves is really needed for at least 16 hours for the manifestation of water nanostructuring [2, 4]; - structured pure water and aqueous solutions, including DNA, especially of extremely low concentrations influenced by the microwave flux from the ionosphere, are apparently capable of emission at frequencies below 3 kHz, taking into account the manifestation of ac Stark shift due to the interaction of the Rydberg electron with the external "thermal" blackbody field. This hypothesis needs to be refined after analyzing the circumstances of the experiment [2]. 1. Avakyan S.V., Baranova L.A., How does the geocosmos control the biosphere? 1. Formation of associates in high deluted water biosolutions under the influence of the microwave flux from the ionosphere // This book. 2. Montagnier L. et al., DNA waves and water // J. of Phys., Confer. Ser., 2011, 306, 012007. 3. Avakyan S. V., Supramolecular physics of the ionosphere – biosphere links // In: Proc. of the 11th Int. School and Conf. “Problems of Geocosmos” (Oct. 03-07, 2016, St. Petersburg, Russia) eds. V.S. Semenov, M.V.Kholeva, S.V. Apatenkov, N.Yu. Bobrov, A.A. Kosterov, A.A. Samsonov, N.A. Smirnova and T.B. Yanovskaya (SPb: St Petersburg State University). C. 180-186. 4. Avakyan S.V., // Herald of RAS, 2017, 87, №2. 136 INFLUENCE OF DIFFERENT IONOSPHERIC DISTURBANCES ON THE GPS SCINTILLATIONS AT HIGH LATITUDES V.B. Belakhovsky1, Y. Jin2, W.J. Miloch2 1 – Polar Geophysical Institute, Apatity, Russia 2 – Department of Physics, University of Oslo, Oslo, Norway E-mail: [email protected] [email protected], [email protected] In this work we compare the influence of auroral particle precipitation and polar cap patches (PCP) on scintillations of the GPS signals in the polar ionosphere. We use the GPS scintillation receivers at Ny- Ålesund, operated by the University of Oslo. The presence of the auroral particle precipitation and polar cap patches was determined by using data from the EISCAT 42m radar on Svalbard. We analyzed more than 100 events for years 2010-2017, when simultaneous EISCAT 42m and GPS data were available. For some of the events, the optical aurora observations on Svalbard were also used. We consider the following types of the auroral precipitation: i) the dayside and morning precipitation, ii) precipitation on the nightside during substorms, iii) precipitation associated with the arrival of the interplanetary shock wave. All considered types of ionospheric disturbances lead to enhanced GPS phase scintillations. For the polar cap patches, the morning and daytime precipitation (i), and precipitation related to the shock wave (iii), the phase scintillations index reaches values less than 1 radian. We observe that auroral precipitation during substorms leads to the greatest enhancement of the phase scintillation index (up to 3 radians). Thus, the substorm precipitation has the strongest impact on the scintillation of GPS radio signals in the polar ionosphere. ON THE CORRELATION BETWEEN LOCAL CRUSTAL MAGNETIC FIELD OF THE MOON AND ION REFLECTION R. Belyaev1, A. Divin1, V. Semenov1, I. Zaytsev1 St. Petersburg University, St. Petersburg, 198504, Russia e-mail: [email protected] This work investigates the correlation between two datasets which are used to study the patches of local crustal magnetization of the Moon’s surface, the so-called Lunar Magnetic Anomalies (LMAs). The first dataset is a global spherical model of Lunar magnetic field with up to N=450 spherical harmonics; the second dataset measures reflection of incident solar wind ions with 1˚x1˚ resolution. Interrelation of reflection coefficient and the model magnetic field was studied for different geographical areas depending on altitude. Regions with large magnetic fields have considerably more pronounced flux of scattered ions. The correlation between magnetic field and reflection coefficient peaks at ~25-30 km above the Lunar surface, which likely corresponds to vertical extent of the formed mini-magnetospheres. Flux of reflected ions contains two rather different components (which are resolved by reflection coefficient), first is a uniform anti-streaming scattered component with <<1% reflection coefficient nearly independent of magnetic field (dominates for surface B<5 nT), and second anomalous component which dominates for surface fields B>40 nT and which increases with magnetic field. In the medium B field range (0… 100 nT) the reflection coefficient fits the shifted hyperbolic tangent function starting from a uniform value of ~0.03-0.07% (near 0 magnetic fields) up to ~10% (anomalous reflection component typical for large >100 nT surface magnetic fields). 137 IONOSPHERE CHARACTERISTICS DURING SIMILAR GEOMAGNETIC EVENTS Blagoveshchensky D.V.1, Sergeeva M.A.2, Shmelev Yu.A.1 1 – Saint-Petersburg State University of Aerospace Instrumentation 2 – CONACYT, SCiESMEX, Instituto de Geofisica, Unidad Michoacan, Universidad Nacional Autonoma de Mexico email: [email protected] The study is focused on the ionospheric response to similar geomagnetic storms. The aim was to estimate how similar/different is the behaviour of ionopheric parameters during the storms of the similar intensity and duration. Two pairs of similar geomagnetic storms were chosen for the analysis. Storms were characterized by the X-component of the magnetic field and Kp-index variations. We used magnetometer, riometer and ionosonde data (F-plots) from Sodankyla observatory (Finland). It was found that the variations of critical frequencies of the ionospheric F2-, F1- and E-layers are not very different for the similar storms. During the daytime hours this difference varied approximately between 0% and 11%. During the night time hours the difference between ionospheric parameters variations depended on the layer. It was about 4% for F2-layer and about 20% - for the sporadic Es-layer. The behaviour of the regular E-layer at daytime during disturbances was similar to its behavour under the quiet geomagnetic conditions. These results show that the geomagnetic storms with similar characteristics can cause the similar effects in the ionosphere. PERSPECTIVES OF MONITORING OF ATMOSPHERIC ELECTRIC FIELD IN THE CENTRAL PART OF KAMCHATKA PENINSULA TO DETECT ATMOSPHERIC-ELECTRIC EFFECTS FROM VOLCANIC ERUPTIONS Cherneva N.V.1, Firstov P.P.1,2, Akbashev R.R.2, Malkin E.I.1 1 - Institute of Cosmophysical Research and Radio Wave Propagation (IKIR) FEB RAS, Paratunka, Russia 2 - Kamchatka Branch of the Federal Research Center «Geophysical survey RAS», Petropavlovsk- Kamchatskii, Russia Electric field determined by the world lightning activity, which globally forms the unitary variation with the maximum at 19-20 UTC, has its peculiarities in each region under the influence of local factors. Based on long-term observations at Paratunka observatory (IKIR FEB RAS), a phenomenological model of the local atmospheric electric field (AEF) was suggested taking into account the main processes affecting the atmospheric near-ground layer. One of the local AEF features on Kamchatka peninsula is volcanic lightning and aero-electric structures occurring during volcano eruptions. During explosive eruptions, when magma fragmentation occurs and a large volume of gas and pyroclastics is emitted into the atmosphere. During eruptive cloud formation, its electrification takes place that causes multiple lightning strokes. Investigation of the relation of lightning strokes with eruption intensity testifies the great role of electrostatic electricity during eruptive cloud formation. Application of systems for the observation of lightning strokes from volcanic lightning to monitor explosive eruptions and the trajectories of their motion at the first stage is an additional method 138 of evaluation of ash hazard for air transportation. Eruptive clouds propagate for hundreds of kilometers under the wind influence. They are aero-electric structures. The paper compares two diurnal variations of AEF potential gradient (V’) of observation sites located in the central part of Kamchatka with continental climate with Paratunka observatory located on the Eastern shore of Kamchatka peninsula. Cases of responses in AEF V’ dynamics on the passage of eruptive clouds, occurring during Shiveluch volcano explosive eruptions, are described. Recording of signals generated during eruptive cloud passage may be one of the components of complex observations over volcano eruptions. Plan for extension of the site network for atmospheric-electric effect recording is presented. DEFINITION OF TEMPERATURE AND SONIC SPEED VALUES AT THE MESOSPHERIC HEIGHTS FROM VARIATIONS OF PARTIAL REFLECTION RADAR SIGNALS Cherniakov S.M., Turyansky V. A. Polar geophysical institute During many years there were observations of partial reflected signals by the partial reflection radar of the Polar Geophysical Institute (the observatory Tumanny, 69.0N, 35.7E) during different heliogeophysical conditions at the heights of the D-region of the ionosphere. Temporary variations of amplitudes of the signals during solar terminator passes which were partially reflected in the height interval of the 75-90 km and their spectra were analyzed. It was found that the components of the time spectrum of the variations corresponding to the resonant frequencies of the atmosphere (the acoustic cut- off and the Brunt-Väisälä ones) in certain cases were intensified. On the basis of the theory of acoustic- gravity waves and the empirical model NRLMSISE-00 of neutral structure and temperature of the atmosphere identification of the experimental periods corresponding to atmospheric resonances was executed and calculation of temperature of the neutral atmosphere and sonic speed values at the mesospheric heights was carried out. The received results showed satisfactory consent with data of other independent observations. COSMIC RAY CUTOFF RIGIDITY CHANGES CAUSED BY THE DISTURBED GEOMAGNETIC FIELD OF THE STORM IN JUNE 2015 Danilova1 O.A., Tyasto1 M.I., Sdobnov2 V.E. 1- St-Petersburg Filial of IZMIRAN 2- Institute of Solar-Terrestrial Physics SO RAN Email: [email protected] One of important factors determining the space weather are cosmic rays the cutoff rigidities of which vary appreciably under the influence of disturbances in the interplanetary space and the Earth's magnetosphere. This report is concerned with the changes in the geomagnetic cutoff rigidities (thresholds) of cosmic rays computed for the period of a strong geomagnetic storm of June 2015. This disturbed period was characterized by the solar wind speed of more than 700 km/s and Dst-index at the minimum Dst – 139 variation equal 204 nT. The theoretical vertical effective geomagnetic cutoff rigidities were calculated for a number of stations by using the Tsyganenko TS01 model and trajectory tracing method in a magnetic field of a disturbed magnetosphere. The theoretical cutoff rigidities were compared with the experimental ones obtained by the global spectrographic survey method on base of the data from the worldwide neutron monitor network. CONJUGATE GROUND-SPACECRAFT OBSERVATIONS OF VLF CHORUS ELEMENTS A. G. Demekhov1,2, J. Manninen3, O. Santolík4.5, E. E. Titova1 1 – Polar Geophysical Institute, Apatity, Russia 2 – Institute of Applied Physics RAS, Nizhny Novgorod, Russia 3 – Sodankylä Geophysical Observatory, Finland 4 – Institute of Atmospheric Physics, The Czech Academy of Sciences, Prague, Czech Republic 5 – Faculty of Mathematics and Physics, Charles University in Prague, Czech Republic We present the results of simultaneous observations of VLF chorus elements at the ground-based station Kannuslehto in Northern Finland and on board Van Allen Probe A. Visual inspection and correlation analysis of the data reveal one-to-one correspondence of several chorus elements following each other in a sequence. Poynting flux calculated from electromagnetic fields measured by the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) instrument on board Van Allen Probe A shows that the waves propagated at small angles to the geomagnetic field and oppositely to its direction, that is, from northern to southern geographic hemisphere. The time delay between the waves detected on the ground and on the spacecraft is about 1.3 s, with ground-based detection leading spacecraft detection. The measured time delay is consistent with the wave travel time of quasi-parallel whistler-mode waves for a realistic profile of the plasma density distribution along the field line. Therefore, chorus wave packets were detected first at Kannuslehto on the ground, and then in 1.3 to 1.4 s they reached the Van Allen Probe A on the opposite side of the magnetic equator. Taking into account the common knowledge about near-equatorial location of chorus generation region, the only realistic scenario which satisfies the observation facts suggests downward propagation of chorus wave packets from the generation region to the ionosphere, partial transmission to the ground, partial reflection from the ionosphere and coming back to the near-equatorial region where they were detected by the spacecraft. A fairly large amplitude of chorus waves measured by the Van Allen Probe A speaks in favor of either good reflection from the ionosphere, or additional cyclotron amplification in the equatorial region on the path from the ionosphere to the spacecraft. The results suggest that chorus discrete elements can preserve their spectral shape during a hop from the generation region to the ground followed by reflection from the ionosphere and return to the near-equatorial region. 140 YOUNGER DRYAS AND RADIOCARBON DATA Dergachev V.A., Kudryavtsev I.V. Ioffe Institute, St. Petersburg It is well known that data of cosmogenic isotope 14С content in the Earth’s atmosphere reflect changes of the Galactic Cosmic Rays (GCR) intensity. This is due to the fact that solar activity (SA) modulates the GCR intensity during their propagation in the Heliosphere that allows us to use the radiocarbon data to study variations of SA during the last centuries and millennia. However, the changes of terrestrial climate distort the information about SA fixed in the radiocarbon data. In the present work we analyze the content of radiocarbon (Δ14C) in the Earth atmosphere in 11-10th centuries BC. This time interval contains the so- called Younger Dryas (≈10700-9700 BC). The Younger Dryas is one of the most well known examples of abrupt climate change. The Younger Dryas is clearly observed in paleoclimatic records from many locations in the world. A sudden cold period after a long period of increased global temperature and melting of glaciers took place during this interval. This cold period lasted for about one thousand years, and about 12 thousand years ago a transition from the Last Glaciation to the interglacial Holocene has happened. During the Younger Dryas the value of Δ14C decreased by 6 %. Is this reduction connected with changes in intensity of GCR or is it related to climatic changes? To answer this question the variations of the absolute value of 14C content in the Earth’s atmosphere, obtained on the basis of Δ14C 14 and the concentration of CO2 in the atmosphere were analyzed. It was found that the major part of Δ C change can be related to the variations of CO2 in the Earth’s atmosphere after its redistribution between the atmosphere and the ocean due to the changes of global temperature. The remaining part of 14C variations ( 2%) in the atmosphere can be connected with alterations of the 14С production rate due to the changes of SA and (or) the geomagnetic field. As a result, during the Younger Dryas there was the reduction of the 14С production rate. As well the content of 14С in various natural reservoirs is analyzed in the present work. This work was partially supported by the Russian Foundation for Basic Research (grant no. 18-02- 00583). THEMIS AND MAIN CAMERA SYSTEM OBSERVATIONS - A CASE STUDY I.V. Despirak1, T.V. Kozelova1, B.V. Kozelov1, A.A. Liubchich1 Polar Geophysical Institute, Apatity, Russia One case of substorm activity on 24 December 2014 by simultaneous THEMIS satellite and ground-based observations was considered. In the interval 16:30-20:00 UT, when the KP index was between 3 and 3+, the complex substorm activity was observed: substorm on 16:45 UT; small substorm-like disturbance on 19:18 UT; small substorm on 19:37 UT and substorm on 19:45 UT. The active auroras were observed by Multiscale Aurora Imaging Network (MAIN) in Apatity, the magnetic disturbances were recorded by IMAGE network, Tixie (TIK), Amderma (AMD) and Lovozero (LOV) magnetometers. Magnetic activation enhancement began between TIK-AMD at ~16:10 UT and then westward expands to AMD and LOV, where Pi2 pulsations at ~16:45 UT observed. For the substorm intensifications at the interval from ~18:30 to ~19:30 UT, the projection of THD satellite orbit crossed Kola Peninsula. We made the detailed comparative analysis of auroras and satellite observations only for first substorm at ~16:45 UT. The temporal evolution of the auroral phenomena are interpreted as the ionospheric manifestation of the 141 process in the near-Earth magnetotail during substorm. We show that the dipolarization fronts (DF) and associated wave intensifications in the magnetosphere were registered during the consecutive auroras activations. The DFs were associated with enhanced energetic electron fluxes, as well as with intense electric fields and intense wave activity. The electric field activity primarily consist of a DC electric field variations and lower hybrid drift (LHD) waves. Electron cyclotron harmonic (ECH) waves were detected slightly after the magnetic field reached a maximum associated with a substorm dipolarization front. Magnetic field energy concentrated around 100 Hz were detected near DF moments. COMPARISON OF DIFFERENT LATITUDE SUBSTORMS DURING TWO LARGE MAGNETIC STORMS I.V. Despirak1, N.G. Kleimenova2, V. Guineva3 1Polar Geophysical Institute, Apatity, Russia 2 Schmidt Institute of the Physics of the Earth RAS, Moscow, Russia 3Space Research and Technology Institute (SRTI), Stara Zagora Department, Stara Zagora, Bulgaria The spatial-temporal development of the substorm westward electrojet has been studied during two large geomagnetic storms: the St. Patric`s day storm (17 March 2015) and the storm on 22 June 2015. These two storms demonstrated some similar behavior: both storms were of the two-step progression and characterized by the very strong intensity (SYM/H<-200 nT), both storms were caused by the solar wind Sheath impact. We have done a comparative analysis of the magnetic substorm dynamics documented during these storms at the INTERMAGNET and IMAGE magnetometer networks. The obtained results were compared with the OMNI data base of the solar wind and Interplanetary Magnetic Field (IMF) parameters. The spatial-temporal dynamics of two substorms has been studied in detail: the first substorm observed at 17:30 UT on 17.03.15 and the second one observed at 18.40 UT on 22.06.15. Both substorms were registered as well at middle and low latitude stations (below ~50°CGLAT) as the positive magnetic bays. The positive bay related to the first substorm was stronger than the positive bay associated with the second one. Both considered substorms were characterized by the sharp poleward expansion of the westward electrojet, which developed simultaneously with their slower drift to the lower latitudes. Then, a further poleward electrojet jump reached the BJN station (~ 71° CGLAT) in the first storm (17.03.2015), and the NAL station (75° CGLAT) in the second storm (22.03.2015). The first considered event was observed during the main phase of the first storm and the second event – in the time of the Storm Sudden Commencement (SSC) of the second storm. Thus, the first case demonstrated the spatial- temporal behavior typical for a “classical” substorm, and the second case –for an “expanded” substorm. We suggested that, probably, that is associated with different solar wind conditions favorable for the development of different substorm types: the “classical” substorms are developed under the magnetic cloud (MC) conditions, and the “expanded” substorms - under the Sheath region impact. 142 LARGE-SCALE TYPES OF THE SOLAR WIND AND APPEARANCE OF MAGNETIC SUBSTORMS I.V. Despirak1, A.A. Liubchich1, N.G. Kleimenova2 1 Polar Geophysical Institute, Apatity, Russia 2 Schmidt Institute of the Physics of the Earth RAS, Moscow, Russia We considered the solar wind streams types and their possible influence on the appearance of the specific magnetic substorms. The catalog of the large-scale solar wind phenomena (ftp://ftp.iki.rssi.ru/omni/) and OMNI data base have been used for determination of the solar wind stream types. We selected substorms by the data of SuperMAG global magnetometers network and meridional chain of IMAGE magnetometers. Three types of substorms have been considered: two types of the substorms observed at the geomagnetic latitudes higher ~ 70° CGC (“polar” and “expanded” substorms) and the supersubstorms (the particularly intense substorms with SML index < - 2500 nT). Six solar wind streams types have been analyzed: the high speed streams from coronal holes (FAST); the interplanetary manifestations of coronal mass ejections: the magnetic clouds (MC) or EJECTA; the regions of compressed plasma before these streams – CIR and SHEATH; the slow solar wind (SLOW) streams. The 186 “polar”, 202 “expanded” and 77 “supersubstorm” (SSS) events have been selected. It was found that these different substorm types occur during different solar wind types. It was shown that supersubstorms events were associated with SHEATH, MC, EJECTA and they almost did not observed during FAST and SLOW. The “expanded” substorms were usually registered during FAST and compressed plasma regions (CIR, SHEATH), as well as during EJECTA. The "polar" substorms were observed during SLOW and EJECTA that occur against the background of a slow flow of solar wind, as well as at the end or at the beginning of FAST, when the solar wind speed already or not yet reaches high values. Thus, the behavior of the ground-based substorms significantly controls by the types of the solar wind streams. COLLISIONLESS MAGNETIC RECONNECTION: 3D STRUCTURE OF JET FRONTS IN THE PRESENCE OF A GUIDE FIELD A. Divin1, V. Semenov1, I. Zaytsev1 St. Petersburg University, St. Petersburg, 198504, Russia e-mail: [email protected] In this study we investigate properties and substructures of reconnection jet fronts (RJFs) developing at the interface between reconnection ejecta and pre-existing plasma sheet. An implicit PIC code is used to perform a set of 2D and 3D numerical simulations of the initial Harris current layer with different guide fields ranging from 0 to 2 (times the upstream magnetic field). First, at earlier stages of the evolution, nearly two dimensional fronts are formed which push the current layer plasma away from the X-line. Fronts accelerate and reflect particles, producing parallel ion beams and increasing parallel ion temperature ahead of the front. Second, we simulate the three dimensional evolution of the fronts at later stages by replicating the 2D configuration (fields and particles). For zero to low guide fields (0, 0.05, 0.45), the Lower Hybrid (LH) range instability develops at the front edge, leading to formation of interchange “fingers” and heating of electrons parallel to the B field. Moderate guide field (~1.0) produces wave activity at the front which however saturates at relatively low amplitude. High guide field (~2.0 times the reconnecting component) magnetizes the front edge completely, with no wave activity 143 produced. Our simulations indicate that the LH-range waves (commonly found at dipolarization fronts in the Earth’s magnetotail) should be suppressed and vanish if the guide field is large enough (~1.0). ON THE SIMILARITY OF THE SERPENTINE EMISSION SPECTRA AT GEOMAGNETIC POLES B.V. Dovbnya1, B.I. Klain2 1,2 Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth, Russian Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia e-mail: [email protected], [email protected] Simultaneous analysis of the serpentine emission (SE) spectrograms at Vostok (corrected geomagnetic coordinates -85.41, 69.01) and Thule (corrected geomagnetic coordinates 86.78, 32.26) observatories was realized. It is shown that the dynamics of the emission frequency modulation at some time intervals is similar. The observed effect allows us to confirm that emission with a deep modulation of the carrier frequency has a natural origin. We put forward this hypothesis about the nature of the observed effect in a series of early works. This work was supported by Russian Foundation for Basic Research 16-05-00056 STATISTICAL STUDY OF THE EFFECT OF THE SUBSTORM ACTIVITY ON THE FORMATION OF NOISE ULF EMISSIONS IN THE FREQUENCY RANGE (0 – 7) Hz B.V.Dovbnya, B.I.Klain, N.A.Kurazhkovskaya Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth, Russian Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia e-mail: [email protected], [email protected], e-mail: [email protected] A study of simultaneous observations of the mid-latitude noise ultra-low-frequency (ULF) emissions in the frequency range 0-7 Hz and perturbations in the nighttime sector of the auroral oval was made. Dynamic spectra of ULF emissions used for the analysis were obtained from the magnetic field observations at the mid-latitude Borok Observatory (L = 2.8) (data from the Archive of the GO Borok IPE RAS) and one-minute AL index data obtained from the World Data Center on Solar–Terrestrial Physics (Moscow, Russia) (http://www.wdcb.ru/stp/geomag/geomagn_AU_AL_AE_AO_ind.html). It is found that in the hertz range, mainly in the summer season, two types of noise ULF emissions are observed together. One of the emissions has the form of a diffuse spots; the other emission is characterized by the presence of resonance spectral structures (ionospheric Alfven resonances - IAR). Noise emissions in the form of diffuse spots have an oval shape and there are no structures in them. The fanlike spectral bands of the increasing or decreasing frequency are clearly visible in the IAR emissions. In total, 334 cases of joint observation of diffuse spots and IAR were analyzed during the period 1985- 1988. Diffuse spots are mainly observed in the evening sector of the magnetosphere. They preceded the appearance of IAR which are recorded predominantly near midnight. The maxima of diurnal distributions of the spots and IAR were shifted by about 6 hours. This confirms that the time of observation of diffuse spots is outstripped in comparison with the time of IAR observation. Simultaneous comparison of the 144 observation intervals of diffuse spots with the AL index dynamics showed that in 80% of cases diffuse spots are formed against the background of the substorm activity development in the evening sector of the auroral zone. In the dominant number of cases, diffuse spots develop through 60 min after the substorms development. It is shown that the probability of diffuse spots observation depends on the AE index magnitude characterizing the intensity of the substorm disturbances. The seasonal variation in the duration of diffuse spots coincides with the seasonal variation of the substorms duration, the maximum duration of which occurs in the summer season. The obtained experimental facts allow assuming that the formation of diffuse spots is associated with the features of the dynamics of injected protons from the tail of the magnetosphere during the substorms and the appearance of plasmospheric plumes in the evening sector. SOME PECULIARITIES OF THE DIURNAL, SEASONAL AND CYCLIC VARIATIONS OF MID-LATITUDE ULF EMISSIONS WITH RESONANCE STRUCTURE OF THE SPECTRUM B.V.Dovbnya, B.I.Klain, N.A.Kurazhkovskaya Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth, Russian Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia e-mail: [email protected], [email protected], e-mail: [email protected] The analysis of the dynamic spectra of ULF emissions in the frequency range (0 - 10) Hz obtained from the data of long-term observations of the magnetic field at the mid-latitude Borok Observatory (L = 2.8) is performed (data from the Archive of the GO Borok IPE RAS). In total, over 2784 days during which the emissions with a resonance structure of spectrum (ionospheric Alfven resonances-IAR) were identified for two observation intervals (1984-1993) and (1997-2016) were analyzed. It was found that in 30% of cases IAR are accompanied by simultaneous observation of structured geomagnetic pulsations Pc1 (“string-of-pearls”) and in 70% of cases IAR are recorded without Pc1 excitation. A characteristic feature of pearls is that they are observed mainly at the frequency of the first resonant band of IAR. In this case the behavior of the frequencies of the IAR and wave packets Pc1 in 80% of the cases is qualitatively the same. We divided the initial data conditionally into two groups: 1) IAR (1951 days of observations); 2) IAR, accompanied by pearls (833 days of observations). It is shown that the maximum probability of the IAR observation of the two groups is dominant until midnight (2000-2200) of MLT. The seasonal variation of the IAR of both groups is characterized by the presence of two equinox maxima. An apparent inverse relationship between the probability of observing IAR and solar activity has been established. The maximum of the IAR observations corresponds to a minimum solar activity. A deviation from this pattern was observed in the 23 cycle of solar activity for the IAR group, accompanied by pearls. In this cycle, the maximum probability of IAR observation falls on the phase of the decline in solar activity, as well as the pulsation of Pc1. It is shown that the 11-year variation of the IAR emissions is controlled by the dynamics of some parameters of the solar wind and IMF. The probability of the IAR observations is maximal when the ratio of the proton density to the density of the helium (α-particle) ions - Np/Na and the parameter (characterizing the ratio of the thermal pressure to the magnetic pressure) reach the maximum values and when the dynamic pressure of the solar wind - Pdyn (controlling compression of the magnetosphere) decreases. The coincidence of dynamics of the frequencies of the first resonance band of IAR and pearls as well as their seasonal and cyclic variation may indicate the interrelation of these oscillatory processes and the possible common mechanism of their generation. 145 THE ELECTRON ENERGY SPECTRA ON THE NIGHTSIDE (r = 6-11 Re) DURING GEOMAGNETIC STORMS Dubyagin S.V.1, Ganushkina N. Y.1,2 1 – Finnish Meteorological Institute 2 – University of Michigan The plasma sheet temperature and density empirical models are often used to compute the fluxes for the boundary of conditions of the inner magnetosphere particle simulations. However, such computation requires information about the particle energy spectrum. It is usually assumed that the spectrum can be described by Maxwellian or kappa distributions. Using THEMIS measurements of the particle flux during the geomagnetic storms, we study the spectral properties of the electron population in the nightside transition region r=6-11 Re. It was found that the energy spectrum cannot be described by any of standard distributions in majority of the cases. If the measured electron fluxes are compared with those computed from the density and temperatures (estimated from measured spectrum assuming some distribution function), the best agreement is obtained for thermal energies (1-10keV) and for kappa distribution with k=3-4. The median relative error of the electron flux estimated in this way is ~30% for the energies ~1-10 keV but it becomes larger than 100% for the energies 40-150keV. The two population fit to the measured spectrum gives much better result. We discuss the possibility of building an empirical model of density and temperature for two populations or building a model of electron fluxes for several energies. ELECTROMAGNETIC FIELDS OF MAGNETOSPHERIC ULF DISTURBANCES IN CONJUGATE IONOSPHERES: CURRENT/VOLTAGE DICHOTOMY E.N. Fedorov 1, V.A. Pilipenko 2 1 - Institute of Physics of the Earth, Moscow ([email protected]) 2 - Space Research Institute, Moscow ([email protected]) A circuit analogy for the magnetosphere-ionosphere current systems has two extremes for drivers of ionospheric currents: the “voltage generator” (ionospheric electric fields/voltages are constant while current varies) and the “current generator” (current is constant while the electric field varies). Here we indicate another aspect of magnetosphere - ionosphere interaction which should be taken into account when considering the current/voltage dichotomy. We show that non-steady field-aligned currents interact with the ionosphere in a different way depending on a forced driving or resonant excitation. A quasi-DC driving corresponds to a voltage generator, when the ground magnetic response is proportional to the ionospheric Hall conductance. The excitation of resonant field line oscillations corresponds to the current generator, when the ground magnetic response practically does not depend on the ionospheric conductance. According to the suggested conception such phenomena as Traveling Convection Vortices should be considered as resonant response of the magnetospheric field lines and they correspond to current generator. Quasi-DC non-resonant disturbances such as Sudden Commencement correspond to voltage generator. Although, there quite a few factors may obscure the determination of the current/voltage dichotomy. 146 ANALYSIS OF CHEMICAL COMPONENTS OF POLAR WINTER ATMOSPHERE DURING RELATIVISTIC ELECTRON PRECIPITATION Golubenko Kseniia1, Mironova Irina1, Rozanov Eugene2, Artamonov Anton3 1 – St. Petersburg State University, St. Petersburg, Russia. 2 – PMOD/WRC and IAC ETHZ, Davos Dorf, Switzerland. 3 – Research Institute for Space Medicine Federal Research Clinical Center of Federal Biomedical Agency of Russia, Moscow, Russia In this paper we consider variability of chemical components of the polar winter atmosphere during relativistic electron precipitation. The spectra of relativistic electron precipitation were obtained from balloon measurements and taking into account for calculation of ionization rates. One-Dimensional Chemical Model of the Atmosphere was used to verify the computed ionization rates and analysis of the chemical composition of the polar winter atmosphere. The results of our analysis show the importance of relativistic electron precipitation during perturbed conditions of the magnetosphere for changes of concentration of chemical components of the polar winter atmosphere. THE INFLUENCE OF FORESHOCK ORIENTATION ON THE POLAR CUSPS OSCILLATIONS Guglielmi A.V., Kozyreva O.V. Institute of Physics of the Earth RAS, Moscow, Russia e-mail: [email protected] Ultra-low-frequency oscillations of the magnetospheric cusps are observed permanently in the near-mid sector of auroral oval in the form of so-called IPCL. In this paper, we posed the question: do electromagnetic waves incident on cusp from the foreshock (it is a special region of cosmic plasma existing before the front of the magnetosphere) affect the IPCL regime? We have proposed a method of experimental investigation, which is based on the idea of the foreshock position dependence on the interplanetary magnetic field orientation. A hypothesis has been put forward on the existence of a specific effect of the IPCL north-south asymmetry. We tested our hypothesis using IPCL observation data from the Hornsund (Spitsbergen) and Davis (Antarctica) observatories. We found confirmation of the hypothesis at a high confidence level of statistical significance. The result of our work is the following: 1. The database for statistical and synoptic studies of the effect of the interplanetary magnetic field on the vibrational activity of magnetospheric cusps has been created. 2. The methodology is proposed for investigation the dependence of the magnetospheric cusps oscillations on the orientation of the foreshock. 3. The hypothesis of existence of the specific north-south asymmetry of magnetospheric cusps oscillations has been confirmed. Our work was partially supported by the Program 28 of the Presidium of RAS, and RFBR project 16-05- 00056. 147 OBSERVATION OF THE PROTON AURORA DYNAMICS AND THE SAR ARC OCCURRENCE AS A CONSEQUENCE OF THE INTENSE CONVECTION AND SUBSTORM Ievenko I.B. Yu. G. Shafer Institute of Cosmophysical Research and Aeronomy, Yakutsk, Russia. It is known that the 486.1 nm line (H-beta) is emitted by atomic hydrogen as a result of precipitation of protons with the energy of ~ 10-30 keV and their charge exchange at the altitudes of ionosphere E layer (proton aurora). The red line of atomic oxygen (630.0 nm) in the aurora is radiated at the ionosphere F2 region altitudes as a result of precipitation of electrons with energies up to ~ 1-2 keV. The velocity of magnetic drift of the charged particles in the magnetosphere is proportional to their energy. The energy of particles does not influence to the electric drift velocity. In this work, the dynamics of electron and proton aurorae in the evening MLT sector at the Yakutsk meridian (130ºE; 200ºE, geom.) during the magnetic storm on January 7, 2015 using the all-sky imager (ASI) is analyzed. The angular westward motion velocity of the auroral structures in the 630.0 and 486.1 nm emissions along the magnetic latitude of 58°N at a high value of electric field of the solar wind – VX×BZ = 9 mV / m (dawn-dusk) has been defined. On the basis of this parameter the value of radial component of the convection electric field and the precipitating protons energy have been estimated. Next, ASI data show an intensification of aurorae in the 630.0 and 486.1 nm emissions in the range of geomagnetic latitudes of 56-61°N and occurrence of the stable auroral red (SAR) arc at latitudes of 49- 52°N in ~20 minutes after the onset of an intense substorm expansion. Measurements aboard the Van Allen Probes A satellite show a sharp increase of fluxes of the energetic Н+, О+ ions (injection boundary) at the L ~ 2.6-3.0 at the same time near the Yakutsk meridian. The satellite registers the overlap of energetic ion fluxes with a plasmapause in this L interval. This region is mapped by the SAR arc at lower latitudes (L ~ 2.2-2.6) pointing to the nondipole configuration of the geomagnetic field in the inner magnetosphere at the current values of SYM-H ~ -120 nT and ASY-H ~ 150 nT. The research is partial supported by RFBR grants No 18-45-140037 р_а EASTWARD PROPAGATION OF THE PC1 WAVES ALONG THE PLASMAPAUSE ACCORDING TO OBSERVATION OF THE DYNAMICS OF PROTON AURORA AND SAR ARC Ievenko I.B., Parnikov S.G., Baishev D.G. Yu. G. Shafer Institute of Cosmophysical Research and Aeronomy, Yakutsk, Russia. The stable auroral red (SAR) arcs are the consequence of interaction of the plasmapause with energetic ions of the ring current. The geomagnetic pulsations Pc1 are registered on the Earth as a consequence of generation of electromagnetic ion cyclotron (EMIC) waves in the equatorial plane of the magnetosphere. The EMIC instability causes scattering of ring current protons into the loss cone. Precipitation of energetic protons and their charge exchange at the heights of the ionosphere E layer can be observed as a proton aurora in the H-beta line of atomic hydrogen. In this work the dynamics of the SAR arc, proton aurora and Pc1 waves in the MLT evening sector at the Yakutsk meridian (130ºE; 200ºE, geom.) using 148 the all-sky imager (ASI) and an induction magnetometer during the growth and expansion of intense substorms on December 31, 2015 is analyzed. During the enhanced magnetospheric convection due to the southward IMF Bz turning ASI observes an equatorward motion of the diffuse aurora (DA) boundary in the 557.7 and 630.0 nm emissions and H-beta (486.1 nm) band from the northern horizon of observation station. At the same time, the weak SAR arc appears equatorward of DA. In 10 minutes after the expansion onset of intense substorm in the midnight MLT sector ASI registers the SAR arc intensity growth from the western horizon toward the east with an angular velocity of ~ 4 deg/ min. As a result, along the arc a few intensity maxima are formed. At the same time, the narrow arc in the H-beta emission with similar dynamics appears northward of the SAR arc at a distance of ~ 0.6º. The induction magnetometer detects a sharp increase of Pc1 pulsation amplitude at frequencies of 0.5–0.7 Hz during the arrival of end of the arc in the H-beta emission to the zenith of observation station. The Pc1 pulsations and the dynamic proton arc are registered within ~ 30 minutes. The SAR arc is registered by ASI until about 1400 UT. We connect the observed phenomena in the SAR arc and proton aurora with the eastward propagation of the excitation region of EMIC waves along the plasmapause in the evening MLT sector. The research is partial supported by RFBR grants No 18-45-140037 р_а AN APPROACH TO REGIONAL THREE-DIMENSIONAL MODELLING OF GROUND ELECTROMAGNETIC FIELD VARIATIONS DURING SPACE WEATHER EVENTS USING RESULTS OF MAGNETOHYDRODYNAMIC MODELLING OF THE EARTH’S MAGNETOSPHERE AND IONOSPHERE Elena Ivannikova1,2, Mikhail Kruglyakov1,3, Alexey Kuvshinov1, Lutz Rastätter4, Antti Pulkkinen4 1Institute of Geophysics, ETH Zurich, Zurich, Switzerland 2Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia 3Geoelectromagnetic Research Centre, Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Troitsk, Russia 4NASA, Goddard Space Flight Center, Greenbelt, Maryland, USA In order to assess the hazard to ground-based technological systems from space weather we developed an approach to regional three-dimensional (3-D) modelling of ground electromagnetic (EM) field variations during space weather events using results of magnetohydrodynamic (MHD) modelling of the Earth’s magnetosphere and ionosphere. The approach involves four main steps. First, we run a global MHD model of the near-Earth space for geomagnetic disturbance of interest. Then, using results of MHD modelling, we compute the spatio-temporal distribution of the external magnetic field for this event on a regular grid at the surface of the Earth. Third, the external field is converted into equivalent current (source of excitation equivalent to 3-D current system), and, finally, for a given source and a given 3-D conductivity model of the Earth the spatio-temporal distribution of the ground EM field is computed in the region of interest. Using this approach and the British Isles as a test region, we perform 3-D modelling of the ground EM field for the Halloween geomagnetic storm in October 2003 and discuss modelling results. 149 BY IMF AND CLOUD RADIATIVE PROPERTIES AFFECT TO THE POLAR TROPOSPHERIC PRESSURE THROUGH THE IONOSPHERIC POTENTIAL IMPACT TO GEC Arseniy Karagodin 1, Mervyn P. Freeman2, Mai Mai Lam2, Eugene Rozanov3, Irina Mironova1 1 - St. Petersburg State University, St. Petersburg, Russia 2 - British Antarctic Survey, Natural Environment Research Council, Cambridge, UK 3 - Physikalisch-Meteorologisches Observatorium World Radiation Center, Davos, Switzerland Given investigation is devoted to evaluate the ground-level pressure response upon the variation of By- component of interplanetary magnetic field (IMF) and changing of the cloud radiative properties that have been examined exploiting chemical-climate model SOCOL v.2. The model was designed for study of different impacts to the climate change. First part of this study is basing on the hypothesis that IMF By is responsible for variations of meteorological parameters in low atmosphere through the solar wind induced variations of the polar cup ionosheric potential. These disturbances are propagated up to lower layers of atmosphere through global electric circuit (GEC). Connection of ionospheric potential with low atmosphere is maintained by downward current density Jz as part of global electric circuit and cloud microphysical process called autoconversion (ACV) rates that linked with variations of Jz see Harrison et al. [2015]. Second part of this work is devoted to investigation from another side the problem highlighted above. Harrison et al. [2015] mentions that increase of ACV rate is following from growing of the droplet fusion rate efficiency. Lubin et al. [1998] highlighted that affect to tropospheric pressure anomalies happens through the changing of the cloud optical properties under the region of polar cup IP. In our model simulations the effective radius for ice and water droplets was set according to Lubin et al. [1998] as 40 m and 10 m correspondingly. A few experiments were carried out for January condition in attempt to distinguish and accept this approach as plausible for establishing connection between ionospheric potential variation and pressure through GEC as well as impact of this effect to the local and global climate change. Reference Harrison, R. G., K. A. Nicoll and M. H. P. Ambaum (2015), On the microphysical effects of observed cloud edge charging, Q. J. R. Meteorol. Soc. (2015) DOI:10.1002/qj.2554. Lubin D., Chen B., Bromwich D. H. ‚ Somerville Richard C. J., Lee Wan-Ho and Hines Keith M. (1998), The Impact of Antarctic Cloud Radiative Properties on a GCM Climate Simulation, American Meteorological Society (1998). 150 CHANGES IN THE POSITION OF THE AURORAL OVAL UNDER CONDITIONS OF DISPLACEMENT OF THE EARTH'S MAGNETIC POLE Kopytenko Yu.A.1, Chernous S.A.2 Petrova A.A.1, Filatov M.V.2 Petrishchev M.S.1 1 - St. Petersburg branch of IZMIRAN (SPbF IZMIRAN), St. Petersburg, Russia 2 - PGI RAS, Apatity, Russia The aura of auroras is in fact a natural coordinate system to which the events of cosmic geophysics in the ionosphere and magnetosphere are tied theoretically and practically. The oval was built according to the International Geophysical Year data more than 50 years ago and is tied to the magnetic pole of the Earth, which has shifted more than 1000 km during this time. It should be expected that the configuration and position of the auroral oval could also be changed. The purpose of this study is to calculate and direct experimental studies of the position of the ovals of the aurora at different times of the day with different perturbations of the Earth's magnetic field in the present conditions of the position of the Earth's magnetic pole. The report assesses the accuracy of measurements of the auroral position relative to the magnetic pole at the current time by analyzing direct optical measurements at the stations of the Polar Geophysical Institute RAS (Lovozero, Barentsburg, Apatity) and the network of stations in Northern Scandinavia (Sodankyla, Kiruna), and from optical measurements from space. Precise data and a three-dimensional component model of the Earth's magnetic field SPbF IZMIRAN will be used to achieve the goal, taking into account the contribution of magnetic anomalies of the lithosphere components in the altitude range from 80 to about 400 km, obtained from aeromagnetic, hydromagnetic and aerospace surveys. ON APPLICATION OF ASYMMETRIC KAN-LIKE EXACT EQUILIBRIA TO THE EARTH MAGNETOTAIL MODELING Daniil B. Korovinskiy1, 2 Darya I. Kubyshkina1, 3 Vladimir S. Semenov2, 4 Marina V. Kubyshkina2, 5 Nikolai V. Erkaev2,3,4, 6 Ivan B. Ivanov5, 7 Stefan A. Kiehas1 1 – Space Research Institute, Austrian Academy of Sciences, 8042 Graz, Austria. 2 – The Earth Physics Department, Saint Petersburg State University, 198504 St. Petersburg, Russia. 3 – Institute of Computational Modelling, FRC "Krasnoyarsk Science Center" SBRAS, 660036 Krasnoyarsk, Russia. 4 – The Applied Mechanics Department, Siberian Federal University, 660041 Krasnoyarsk, Russia. 5 – Theoretical Physics Division, Petersburg Nuclear Physics Institute, 188300 Gatchina, Russia. A specific class of solutions of the Vlasov-Maxwell equations, developed by means of generalization of the well-known Harris-Fadeev-Kan-Manankova family of exact two-dimensional equilibria, is examined and utilized for the Earth’s magnetotail modeling. The presented model is developed to reproduce the current sheet bending and shifting in the vertical plane, arising from the Earth dipole tilting and the solar wind nonradial propagation. It is shown that for any level of magnetospheric activity the model parameters may be adjusted to fit averaged magnetotail configurations, rendered by the empirical Tsyganenko model, in terms of the magnetic flux tube volume. The best match of the essential model 151 parameters is found for single-peaked current sheets with medium values of number density, proton temperature and drift velocity. Then the problem of MHD stability of bent magnetotail current sheets is considered by means of 2.5- dimensional numerical simulations. The study is focused on the cross-tail transversal mode, modeling the magnetotail flapping motions. It is found that in a planar Kan-like current sheet oscillating and slowly growing unstable flapping modes are coexisting, so that for low levels of bending current sheet is essentially stable on the substorm time scale. As the degree of bending is increased, the growth rate increases and oscillating mode vanishes, hence the typical time scale drops to several minutes. It is also demonstrated that contrary to the usual ballooning modes, this instability is not related to buoyancy/entropy considerations, but is instead controlled by the cross-sheet distribution of the total pressure. The results show qualitative agreement with the so-called double-gradient model. THE DRIFT-COMPRESSION MODES IN THE MAGNETOSPHERIC PLASMA Kostarev D.V.1, Mager P.N.1, Klimushkin D.Yu.1 1 - Institute of Solar-Terrestrial Physics SB RAS, Irkutsk, Russia The theory of drift-compression modes with azimuthal wavenumbers m>>1 is elaborated in gyrokinetic framework. The theory takes into account the bounce motion of energetic particle and the drift wave- particle resonance. The integral equation for structure of these modes is obtained analytically and solved numerically. For the existence of these modes the finite plasma pressure and plasma inhomogeneity transverse the magnetic shells are sufficient. It was found that these oscillations are narrowly localized near the geomagnetic equator and are symmetric with respect to it. They can propagate either to the west, while resonantly interacting with energetic protons, or to the east, interacting with energetic electrons. These modes can be generated by gradient instability when protons temperature increases with distance from the Earth, and by the “bump-on-tail” instability. The drift-compressional modes can provide a natural interpretation for the compressional storm-time Pc5 waves with frequencies much lower than the Alfven frequency on the same magnetic shells. This study was supported by the Russian Science Foundation under grant 18-17-00021. VIRTUAL MAGNETOGRAMS – NEW TOOL FOR THE STUDY OF SOLAR WIND-MAGNETOSPHERE COUPLING Kozyreva O.V.1, Pilipenko V.A.2, Soloviev A.A.2 1 – Institute of Physics of the Earth, Moscow 2 – Geophysical Center, Moscow Magnetic disturbances on the ground, being the images of processes of solar-wind/magnetosphere interaction, can be monitored by comparing time-series of magnetic records on the ground with the space weather parameters. However, a serious drawback of the analysis of ground-based magnetograms is the inevitable variation of the magnetic response due to continual changes of the station location. An ideal, but impossible, solution of this difficulty, that will help to discriminate temporal and spatial variations, would be the deployment of a “stationary” observatory with a fixed position in the solar-magnetospheric 152 coordinate system. However, the desired result can be obtained with the proposed technique of “virtual magnetograms” (VM). This technique has been implemented for key magnetospheric domains (midnight auroral and dayside cusp regions) as an additional tool for monitoring the response of the geomagnetic field to the solar wind and interplanetary magnetic field (IMF) forcing. VM for a fixed reference system is reconstructed by 2D spatial gridding of 1-min magnetic data from world-wide distributed magnetic stations. The VMs have been produced for the period since 1996 up to nowadays. A wide range of space physics studies, such as substorm triggering, solar wind-ionosphere interaction, sawtooth oscillations, ionospheric convection response to IMF variations, etc. will benefit from the introduction of the VMs. The database of calculated VMs for the dayside cusp and midnight auroral regions, as well as simultaneous interplanetary parameters (solar wind electric field) and geomagnetic indices (AE-index) are available via the specially designed site http://vm.gcras.ru/ for all interested researchers for testing and validation. INTERMITTENCY STATISTICS OF HIGH-LATITUDE GEOMAGNETIC PULSATIONS PI2 N.A.Kurazhkovskaya, B.I.Klain, I.A.Yelagina Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth, Russian Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia e-mail: [email protected]; [email protected], [email protected] In this work, we present the results of a comparative analysis of the intermittency conformities of two Pi2 geomagnetic pulsations groups: 1) isolated bursts (970 events) and 2) burst series (1239 events). For the study we used the data of the magnetic field observations from the Molodezhnaya Antarctic observatory (corrected geomagnetic coordinates - 66.7, 76.0) during the period of 1981-1992 (data from the archive of the GO BOROK IPE RAS). It has been shown that the cumulative distribution functions of the amplitudes of both isolated Pi2 bursts and burst series are well approximated by power functions. As a characteristic of intermittency, we considered index α, which reflects the slope of the cumulative distribution function of the amplitudes of the Pi2 bursts. The diurnal and seasonal variations of the parameter α of both groups of Pi2 pulsations were investigated. It was found that the diurnal dynamics of α isolated Pi2 bursts is characterized by a maximum (α = 6.41) in the post-midnight hours (0100-0200 MLT). In contrast to Pi2 isolated bursts, a maximum (α = 5.59) of the diurnal variation of the parameter α of the Pi2 burst series is observed in the evening sector (2000- 2100 MLT). The seasonal dynamics of the index α of Pi2 isolated pulsations is characterized by the presence of two maxima: in the season of spring (α = 3.57) and fall equinoxes (α = 3.27). In the seasonal variation of the index α of Pi2 bursts series two maxima are also distinguished, but in contrast to isolated bursts in the season of summer (α = 8.06) and winter solstices (α = 8.03). Thus, the behavior of the parameter α for the two Pi2 bursts groups varies significantly depending on the MLT and season. The obtained results indicate that high-latitude bursts of both Pi2 pulsations groups are generated in a highly turbulent medium (the value of α is significantly > 1). This allows us qualitatively to estimate the degree of the plasma turbulence of the magnetosphere tail during their excitation. The burst series of Pi2 pulsations are generated in a more turbulent medium in the evening time than at other time intervals. At the same time, the degree of plasma turbulence is relatively high after midnight during the excitation of isolated Pi2 bursts. Depending on the season the level of turbulence of the magnetosphere tail is higher in the equinox and solstice during the excitation of isolated bursts and a series of bursts of pulsations Pi2, respectively. It is assumed that the differences in the regularities of the intermittency of the two Pi2 bursts groups are due to peculiarities of the substorms behavior. 153 EFFECT OF THE SOLAR WIND AND IMF PARAMETERS ON POLARIZATION CHARACTERISTICS OF HIGH-LATITUDE GEOMAGNETIC IMPULSES (MIES) N.A.Kurazhkovskaya, B.I.Klain Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth, Russian Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia e-mail: [email protected]; [email protected] The results of the study of polarization characteristics (polarization type, ellipticity - ε, inclination angle of the main axis of the polarization ellipse - τ) of the high-latitude magnetic impulse events (MIEs) and the effect of interplanetary medium parameters on them are presented. We used the observations of a magnetic field with a minute resolution at the Antarctic observatory Mirny (corrected geomagnetic coordinates -76.93, 122.92) [http://www.wdcb.ru/stp/data/geo_min.val/] and one-minute data of the solar wind and interplanetary magnetic field (IMF) parameters [http://omniweb.gsfc.nasa.gov/ow.html] for the period 1989-1991, 1995-2003. We divided all analyzed impulses into two groups according to the type of polarization: 1) right-polarized impulses (R - type); and 2) left-handed impulses (L - type). It is established that R-type MIEs occur when the IMF vector is close to the radial direction, and L - type MIEs occur when a direction perpendicular to the Sun - Earth line. It has been shown that near the moment of the onset both types impulses the orientation of the IMF Bz - component changes from the northern direction to the southern direction. In this case, the direction of rotation of the IMF vector in the XY plane of the solar - ecliptic coordinate system coincides with the direction of rotation of the main axis of the polarization ellipse of impulses recorded on the Earth’s surface. The IMF vector rotates clockwise and counterclockwise in the ecliptic plane in the case of the R and L type MIEs observation, respectively. A reverse dependence of the τ angle of the R - type impulses and ε of the L - type impulses on the Bz - component value was found. Also, the behavior of the polarization characteristics of impulses depends essentially on the angle θxB value, where θxB = arccos (Bx/B). The ellipticity of the R-type impulses reaches its maximum values at θxB ~ 45-60 and θxB ~ 135-150. The ellipticity of the L-type impulses is minimal at the same ranges of angle θxB. The value of the τ angle of the R-type impulses is maximal for the direction of the IMF vector perpendicular to the Sun-Earth line (θxB ~ 90-105), and L-type impulses for θxB ~ 60-75. It is assumed that under conditions of a quiet or moderately perturbed magnetosphere a trigger of geomagnetic impulses of two types is the weak short-term variations of the IMF Bz - component, whose source is the solar wind nonuniformities with the arc-shaped configuration of the IMF hodograph curve in the ecliptic plane that determine the type of polarization of the impulses. CONSTRAINING THE EARLY EVOLUTION OF VENUS AND EARTH BY REPRODUCING ELEMNTAL RATIOS Lammer H. Austrian Academy of Sciences, Space Research Institute, Schmiedlstr. 6, 8043 Graz, Austria e-mail: [email protected] Compositional variations between chondrites, the solar nebula, and the chemical abundances of the terrestrial planets provide evidence that elemental (K/U, etc.) and isotopic fractionation of atmospheric 154 noble gases should have taken place early in the history of their evolution. During the disk-embedded phase, early in the evolutionary history of the solar system, protoplanetary cores of Venus and Earth are 182 182 believed to accumulate hydrogen gas and to form thin planetary H2-envelopes. According to Hf- W isotope studies, the protoplanets of both terrestrial planets should have accumulated about 0.45-0.75 Earth-masses, respectively, until the circumstellar disk evaporated. Afterwards, related to the young Sun, EUV-driven hydrodynamic escape started to slowly evaporate the accumulated H2-envelopes of both proto-planets. Additionally, constant bombardment of impacting material, delivered further material to growing proto-Earth and -Venus. Lighter elements, such as potassium (K) compared to the heavier uranium (U), as well as atmospheric noble gas isotopes, as for example 36Ar compared to 38Ar, or 20Ne compared to 22Ne can escape easier from the accreting proto-Earth and proto-Venus due to hydrogen-drag from a nebula-captured hydrogen-envelope, compared to a magma ocean related outgassed steam atmosphere. Heavier elements and isotopes cannot be dragged away that easily. Simulations of the hydrodynamic escape of the accumulated hydrogen envelope around proto-Earth and proto-Venus show that this effect can explain initial compositional variations between the terrestrial planets and the solar nebula. It is also shown that in the case of the Earth delivery of chondritic material is necessary to reproduce the observed fractionations. These model results are also supporting the Grant-Tack scenario, 182 and are in agreement with Hf-182W chronometric fast accretion scenarios of the Earth with a late Moon- forming giant impact. KELVIN-HELMHOLTZ INSTABILITY OF THE LOW-LATITUDE BOUNDARY LAYER OF THE GEOMAGNETIC TAIL Leonovich A.S.1, Kozlov D.A.1 1 – ISTP SB RAS, Irkutsk The low-latitude boundary layer (LLBL) stability problem in the geomagnetic tail is studied. To describe the boundary layer between plasma sheet and magnetosheath, we use a cylindrical model of the tail enwrapped by a helical solar wind flow. Unlike plane-stratified medium models, the cylindrical model allows us to take into account the finite cross-section of the tail and the curvature of closed field lines in the LLBL region. The problem is investigated both in the tangential discontinuity (TD) approximation and for a finite thickness transition layer. It is shown that there are three types of unstable MHD modes that can develop in the region: 1) surface modes on the LLBL, 2) radiative modes (waves radiated into the solar wind), and 3) the eigen-modes of the tail waveguide. The dispersion equation solution in the TD approximation shows that symmetric modes (m = 0) are unstable for any low-speed flows, while asymmetric modes (m > 0) become stable when solar wind speed is lower than a certain threshold. All modes become stable when solar wind flow speed are higher than a upper threshold, so the surface waves can be generated in the low- to medium-speed solar wind (200-400 km/s). The non-zero azimuthal component of the flow velocity (described by the helicity index, the ratio of azimuthal to axial velocity) significantly affects both the Mach number dependence of the surface wave growth rate and the velocity threshold values. The higher the helicity index, the lower the magnitude of the upper threshold. The surface modes have the largest growth rate. When taking into account the finite thickness of the shear layer, the dependence of the growth rate on the flow speed and tangential wavelength demonstrates a local maximum at the wavelengths of the order of the LLBL thickness and at the Mach number M ≈ 0.5. As the Mach number increases, the surface waves gradually transform into radiative modes. The radiative modes remain unstable even when their wavelength is much less than the shear layer thickness. The plot of γ vs f (where γ = Im(ω), and f = Re(ω)/2π) shows that the waves generated by low- and medium-speed solar wind flows (v0 = 200, 400 km/s) have a maximum at frequency f ≈ 0.02 Hz, and the range of unstable oscillations corresponds to the Pc3–Pc6 range. 155 In the high-speed flows (800 km/s) with a small helicity index, the maximum growth rate of unstable oscillations is at frequency f ≈ 0.01 Hz. The maximum frequency above which the oscillations become stable is f ≈ 0.02 Hz, and the unstable oscillations occupy the Pc4–Pc6 range. These oscillations are radiative modes with much smaller growth rates than surface waves generated in low- and medium-speed solar wind flows. In solar wind flows with high helicity index unstable radiative modes have a higher growth rate, and their frequency range occupies the entire Pc1-Pc6 range. IONOSPHERIC DISTURBANCE CAUSED BY RADIATION OF CHELYABINSK BOLIDE FLIGHT Losseva T.V.1, Golub’ A.P.2, Lyakhov A.N.1, Kosarev I.B.1 1 - Institute of Geosphere Dynamics RAS, Moscow, Russia 2 - Space Research Institute RAS, Moscow, Russia A physical model of the action of radiation from a bolide on Earth’s lower ionosphere at the stage of its flight is presented. The calculations within this model are applied to the Chelyabinsk bolide case on February 15, 2013. Thermal radiation fluxes impact on the lower ionosphere accompanying the passage of the Chelyabinsk bolide is studied by means of numerical solution within the radiation gas dynamics model from the 60 km altitude, where bolide entries into the dense layers of the atmosphere and its evaporation begins, to the height of 30 km, where a body separates to large fragments with further disruption. This model includes all necessary physical processes: the deceleration and ablation of the meteoroid in the atmosphere within the framework of physical theory of meteors; radiation gas dynamical processes in the vaporized meteor substance and ambient air as well; the far field thermal radiation transfer in the atmosphere; the excitation of the lower ionosphere described, in turn, by 22 components plasma-chemical model, including the set of minor short-lived constituents. Numerical modeling was performed using tables of thermodynamic and optical characteristics of the air and meteoroid material vapor (LL-Chondrite), calculated based on a mixture of 16 elements: Fe-O-Mg-Si-C-N-H-S-Al-Ca-Na - K-Ti-Cr-Mn-Ni. Verification of the model was evaluated on the luminosity curves in visible and near infrared ranges obtained at different points of ground-based observations and satellite measurements, as well as with the existing integral optical data. The results show that the radiation of the Chelyabinsk bolide in the first 10 seconds of his flight from 60 to 30 km altitude caused the formation in the Earth's ionosphere (80-120 km) of wide ionized region with dimensions of the order of 400 km and the electron density within this region increased to the plasma frequency of 3.5 MHz. This quantitatively coincides with EKB SuperDARN radar system data. The total electron content (TEC) perturbation of 0.1 TECU is consistent with observations at the GPS registration system stations in the Ural region. During this time, meteoroid energy radiation losses are as large as approximately 40% of its total energy (where 15% are in the photon energies range of 1.1-3.1 eV). The numerical models of geophysical effects caused by meteoroid flights in Earth’s upper and middle atmosphere would include radiation effects. 156 SIMULTANEOUS OBSERVATIONS OF A COMPRESSIONAL Pc5 WAVE BY EKB RADAR IN THE IONOSPHERE AND BY VAN ALLEN PROBES IN THE MAGNETOSPHERE Mager O.V., Chelpanov M.A., Mager P.N., Klimushkin D.Yu., Berngardt O.I. Institute of Solar-Terrestrial Physics SB RAS The work presents an analysis of a Pc5 wave registered on November 22, 2014 simultaneously by Ekaterinburg decameter coherent radar (EKB radar) in the night ionosphere and by Van Allen Probes in the conjugate region of the magnetosphere near the geomagnetic equator between 5.5 and 5.9 L-shells. The wave had frequency about 1.8 mHz and was observed after an increase in geomagnetic activity, in the recovery phase of a substorm. Probably, the observed wave is a drift-compressional mode: its frequency was much lower than the estimated lowest Alfvén frequency; the wave had a predominant longitudinal magnetic component in antiphase to the observed plasma pressure oscillations, and was accompanied by an increase in the flux of energetic protons. Besides, the direction of wave propagation coincided with the direction of the magnetic drift of the energetic protons: the azimuthal wave number m calculated on the basis of radar and satellite data was about -10. And indeed, a modulation of proton fluxes with energies 81.6 and 99.4 keV at the wave frequency was found. The magnetic drift velocity of protons with these energies is close to the phase velocity of the wave. Therefore, it is possible that the wave was generated due to the resonant wave-particle interaction (drift instability). ELEMENTS OF FORECASTING OF SPACE WEATHER AND IONOSPHERIC PARAMETERS Maltseva O.A.1, Bezvytnyj S.A.2, Morozov B.E.2, Shilov D.I.2, Shmelev J.A.2 Institute for Physics ,SFU, Rostov-on-Don, Russia Saint-Petersburg State University of Aerospace Instrumentation Corresponding author e-mail: [email protected] The forecast of space weather means prediction of the parameters of the solar wind, the interplanetary magnetic field, Kp, Dst and others indices and is currently reliable enough and is provided on several sites. In this connection, it is possible to predict the behavior of ionospheric parameters, in particular, the total electron content TEC during disturbed conditions. For this, it is necessary to know the functional dependence of the deviations δTEC of the instantaneous values of TEC from the medians. Authors of the paper (Stankov, Jakowski, Acta Geod. Geoph. Hung., 2006, 41(1), pp. 1–15) demonstrated the possibility of predicting δTEC using a polynomial dependence on Kp of degree n = 3. In the present work, for all the disturbances of 2013 (17 cases were identified), the polynomial dependences of δTEC on the Kp and Dst indices were calculated and the reliability of the R^2 approximation for various points of the globe was estimated. The preliminary results are as follows. 1. The degree and the best correlation index depend on the latitude (for high-latitude stations the greatest correlation is observed with the Kp index, for middle- and low-latitude stations the correlation with Dst may predominate.) 2. The degree and best correlation index depend on the season (the greatest correlation is observed in the winter months for high-latitude stations and in summer for low-latitude stations.) 3. The degree of n = 3 is insufficient for approximation, often the degree of reliability R^2 for n=4-6 exceeds the reliability for n= 3. 4. The degree of reliability can exceed a level of 0.5, indicating both a strong connection and the possibility of forecasting. 157 This work was supported by grant № 18-05-00343 from Russian Foundation for Basic Research. MODELING AND ANALYSIS OF IONOSPHERIC CRITICAL FREQUENCY DATA ON THE BASIS OF A MULTICOMPONENT MODEL Mandrikova O.V., Fetisova N.V., Polozov Yu.A. Institute of Cosmophysical Research and Radio Wave Propagation (IKIR FEB RAS) The paper is aimed at developing the methods for the analysis of ionospheric data and studying the processes in the ionosphere during disturbed periods. The subject of the study is ionospheric anomalies (ionospheric storms) that occur during increased solar activity (ex. CME) and magnetic storms. They often occur in the equatorial and auroral zones, but can also be observed in the mid-latitudes [1]. The accuracy of the current methods for analysis of ionospheric data (median method, IRI model, and etc.) much depends on the presence of qualitative input parameters (indices of solar and geomagnetic activity, solar radiation spectra and etc.). At present, the problem of the operational analysis of recorded ionospheric data and the timely detection of ionospheric anomalies is the most urgent. A multicomponent model (MCM) of ionospheric parameters, first suggested in the paper [2], is presented in this work. The model allows to describe regular and anomalous changes of ionospheric parameters and is implemented numerically (http://aurorasa.ikir.ru:8580). MCM identification is based on the application of various schemes of the wavelet decompositions and the classical autoregressive models (ARIMA). The computational algorithms, developed by MCM, are adapted for real-time mode. They allow to operationally detect ionospheric anomalies and to estimate their parameters. Modeling and analysis of the foF2 ionospheric critical frequency data at stations Paratunka (IKIR FEB RAS, Kamchatka) and Wakkanai (Japan) were performed by the MCM. A comparison of the MCM with the median method and IRI-2012 was performed. The obtained results showed the efficiency of the proposed model and the possibility of its use for the operational detection of anomalous changes in the ionosphere, preceding and accompanying magnetic storms. The paper was supported by RSF Grant No. 14-11-00194. The authors are grateful to the organizations recording the data which were applied. Danilov A.D. Ionospheric F-region response to geomagnetic disturbances // Advances in Space Research. 2013. Vol. 52. No. 3. pp. 343–366. Mandrikova O.V., Fetisova N.V., Polozov Y.A., Solovev I.S., Kupriyanov M.S. Method for modeling of the components of ionospheric parameter time variations and detection of anomalies in the ionosphere coupling of the high and mid latitude ionosphere and its relation to geospace dynamics // Earth, Planets and Space. 2015. Vol. 67. No 1. pp. 131-146. DOI: 10.1186/s40623-015-0301-4 158 ANALYSIS OF NEUTRON MONITORS DATA DURING THE PERIODS OF HELIOSPHERIC DISTURBANCES Mandrikova O.V., Zalyaev T.L., Mandrikova B.S. Institute of Cosmophysical Researches and Radio Wave Propagation FEB RAS email: [email protected] Introduction. The work is devoted to the development of methods for the analysis of variations of galactic cosmic rays (GCR) (according to the world network of neutron monitors) and the sporadic effects. The study of GCR data is important for fundamental research in the field of solar-terrestrial physics, as well as for applied research in space weather prediction problems [1]. Existing traditional methods of analyzing GCR data (spectral methods, smoothing, etc.) are not sufficiently effective [2]. Modern methods and approaches (ring station method, global survey method [3]) are effective, but require laborious calculations and their automation is very difficult [4]. At present, the urgent task is to quickly analyze the recorded GCR data and timely detect sporadic effects that have a negative impact on modern space vehicles and human health. Methods. In the paper, the authors presented a generalized model of cosmic-ray data describing recurrent and sporadic variations. A method for identifying a model based on a combination of a neural network apparatus and a wavelet transform is proposed. The application of the model makes it possible to efficiently isolate recurrent components in the dynamics of cosmic rays and to identify sporadic features. Based on neural networks of vector quantization, authors developed a method for analyzing data from neutron monitors, which makes it possible to estimate the state of the GCR flux in automatic mode. The computational algorithms implementing the method classify the data into three classes: "quiet class", which determines the recurrent course of the GCR; "Weakly disturbed class" - defines sporadic effects of small amplitude and "disturbed class" - determines sporadic effects of large amplitude. Experiments. Based on the developed methods, the authors studied the dynamics of GCR during periods of strong and moderate magnetic storms for 2015-2016. (the data of the neutron monitors of Kingston and Apatity (www.nmdb.eu) were analyzed). Periods of occurrence of sporadic variations in GCR are identified; their intensity, duration and moments of occurrence are evaluated. On the eve of most of the analyzed magnetic storms, anomalous changes in the dynamics of GCR observed during the periods of growth of the velocity of the solar wind and the amplitudes of the interplanetary magnetic field were allocated. Conclusions. The efficiency of proposed methods is experimentally confirmed, the method of their implementation in automatic mode is proposed. Further authors plan to carry out approbation of the developed methods on more representative statistics with the expansion of the number of analyzed data recording stations. The authors are grateful to the Russian Science Foundation for the financial support of the study (Project No. 14-11-00194-P) and are grateful to the organizations that are registering the data that was used in the work. References Belov, A. V, Dorman, L.I., Eroshenko, E.A., Iucci, N., Villoresi, G., Yanke, V.G., 1995. Search for Predictors of Forbush Decreases, in: Proceedings of 24Th International Cosmic Ray Conference. pp. 888– 891 Vipindas V, Gopinath S, Girish TE (2016) Periodicity analysis of galactic cosmic rays using Fourier, Hilbert, and higher-order spectral methods. Astrophys Space Sci 361:. doi: 10.1007/s10509-016-2719-y Nagashima K, Sakakibara S, Murakami K, Morishita I (1989) Response and yield functions of neutron monitor, galactic cosmic-ray spectrum and its solar modulation, derived from all the available world-wide surveys. Nuovo Cim C 12:173–209. doi: 10.1007/BF02523790 159 Grigoryev VG, Starodubtsev SA (2015) Global survey method in real time and space weather forecasting. Bull Russ Acad Sci Phys 79:649–653. doi: 10.3103/S1062873815050226 IN SEARCH OF DISTURBANCES OF THE UPPER IONOSPHERE AND GEOMAGNETIC FIELD ABOVE HURRICANES AS OBSERVED BY SWARM SATELLITES 1 Martines-Bedenko V.A.1, 2 Pilipenko V.A.1,2, 3 Zakharov V.I.3 1 - Institute of Physics of the Earth, Moscow 2 - Space Research Institute, Moscow 3 - Moscow State University, Moscow Intense meteorological disturbances of the atmosphere accompanied by the generation of atmospheric large-scale waves and small-scale turbulence may influence the ionospheric plasma and geomagnetic field. In search of additional evidence of these effects we analyze the data of electromagnetic and plasma measurements from low-Earth-orbit SWARM satellites above the hurricane VongFong 2014. These data show the occurrence of large-scale (about few hundred km) soliton-like disturbances of plasma with relative amplitudes up to few tens %. These disturbances are supposedly caused by internal gravity waves generated by the hurricane. The SWARM magnetometers detected in the upper ionosphere above the hurricane "magnetic ripples" - low-amplitude (0.5-1.5 nT) fluctuations with dominant periods about few tens of sec. A spot filled with magnetic ripples is produced by field-aligned currents stimulated by acoustic waves emitted by the hurricane. NUMERICAL METHODS IN THE PROBLEM OF STUDYING THE EFFECT OF COSMIC RAYS ON THE EARTH'S ATMOSPHERE Maurchev E.A.1, Balabin Yu.V., Gvozdevsky B.V., Mikhalko E.A., Hermanenko A.V., Belakhovsky V.B. 1 – Polar geophysical institute [email protected], [email protected] Primary cosmic rays (CR) include in their composition different types of particles (electrons, various nuclei and protons, the percentage of which varies within 85-90 percent). Invading the atmosphere of the Earth, these particles transmit its energy to the substance through a series of successive processes, and if ionization prevails at a conditional height from 80 km to 10-15 km, then the nuclear-active component undergoes inelastic collisions in denser layers. As a result, cascades of secondary CRs are formed. Investigation of the characteristics of these particles (energy spectra, ionization profiles, angular distributions, altitude profiles) is one of the most important tasks of astrophysics of the CR. At the present day, mostly experimental methods are used for this, but with the development of information technologies, numerical models based on the Monte Carlo method are increasingly being used. This approach makes it possible to significantly expand the field of studying CR in the Earth's atmosphere. 160 In this paper, the results of calculating the passage of CR particles of different types through the atmosphere of the Earth, obtained with the program complex RUSCOSMICS, are presented. This software is a development of the PGI team, based on GEANT4 tools and adapted for narrowly focused tasks. VALIDATION OF THE RESULTS OF MODELING THE PASSAGE OF COSMIC RAYS THROUGH THE EARTH'S ATMOSPHERE BY EXPERIMENTAL DATA Mikhalko E.A. 1, Maurchev E.A., Germanenko A.V., Balabin Yu.V. 1 – Polar geophysical institute The corresponding module of the RUSCOSMICS software allows calculating the passage of particles of cosmic rays (CR) of various kinds through the layers of the Earth's atmosphere, obtaining information about the energy spectra of the streams, their altitude and ionization profiles, and angular distributions with a variety of initial conditions. In order for the final result to be the most correct, at the end of the simulation it is necessary to perform validation. Especially for this, based on the already available developments of several scientific groups from different institutions, a technique was developed that makes it possible to compare the experimental data with the results obtained by numerical modeling. In the work presented, an example of using data from balloons and a ground-based detector of charged particles is shown. A NUMERICAL MODEL OF THE HORIZONTAL AND VERTICAL WIND IN THE EARTH’S ATMOSPHERE AND ITS IMPROVEMENTS Mingalev I.V.1, Orlov K.G.1, Mingalev V.S.1*, Chechetkin V.M.2 , Mingalev O.V.1 1 Polar Geophysical Institute, Apatity, Russia 2 Keldysh Institute of Applied Mathematics, Moscow, Russia E-mail: * [email protected] To investigate the influence of the space weather on the planetary wind system of the Earth’s atmosphere not only the experimental and theoretical but also computational studies may be applied. In the Polar Geophysical Institute, not long ago, the mathematical model of the global neutral wind system in the Earth’s atmosphere has been developed. The initial version of this model enabled to calculate three- dimensional global distributions of the zonal, meridional, and vertical components of the neutral wind at levels of the troposphere, stratosphere, mesosphere, and lower thermosphere. The initial version of this model, as well as all following versions of the model, are non-hydrostatic, that is, not only the horizontal components but also the vertical component of the neutral wind velocity is obtained by means of a numerical solution of a generalized Navier-Stokes equation for compressible gas. Thus, the hydrostatic equation is not utilized in all versions of this model. In the initial version of the mathematical model, the internal energy equation for the neutral gas was not solved in the model calculations. Instead, the global temperature field was assumed to be a given distribution, i.e. the input parameter of the model, and obtained from one of the existing empirical 161 models. Later, the internal energy equation for the atmospheric gas has been included in the system of governing equations of the mathematical model. The internal energy equation has been written by using a relaxation approach, in which a heating / cooling rate of the atmospheric gas in various chemical- radiational processes is supposed to be straightly proportional to the difference between the real temperature of the atmospheric gas and an equilibrium temperature of the atmospheric gas. The latter equilibrium temperature was given by utilizing the global temperature field, obtained from one of the existing empirical models. In the initial version of the mathematical model, the Earth’s surface was assumed to be a smooth sphere. Later, the form of the Earth has been changed from the sphere to an oblate spheroid whose radius at the equator is more than that at the pole.. Results of simulation indicated that the non-sphericity of the Earth ought to influence appreciably on the global circulation of the lower and middle atmosphere. In the latter versions of the mathematical model, it was supposed that the Earth’s surface is smooth. Recently, the mathematical model has been improved by taking into account the relief of a planet. Therefore, a planetary surface can contain mountains. The Earth’s surface is approximated by using one of the existing digital maps of the surface relief of a planet. Thus, in the last version of the mathematical model, the atmospheric gas is considered as a mixture of air and water vapor, in which two types of precipitating water (namely, water microdrops and ice microparticles) can exist. The system of governing equations contains the equations of continuity for air and for the total water content in all phase states, momentum equations for the zonal, meridional, and vertical components of the air velocity, and energy equation. The last version of the mathematical model is based on numerical solving of the system of governing equations and produces three-dimensional time- dependent distributions of the wind components, temperature, air density, water vapor density, concentration of micro drops of water, and concentration of ice particles. The system of governing equations is numerically solved in a simulation domain which is a layer surrounding the Earth globally, with the relief of a planet being taken into account. The finite-difference method is applied for solving the system of governing equations. The calculated parameters are determined on a uniform grid. The latitude and longitude steps are equal to 0.47°, and height step is equal to 200 m. In the last versions of the mathematical model, parallel computing is utilized for numerical solving the system of governing equations. The program packages were developed using both CPU, by OpenMP technology, and GPU NVIDIA, by CUDA technology. The different versions of the mathematical model have been utilized in order to investigate numerically how various geophysical conditions influence on the formation of the global wind system of the Earth’s troposphere, stratosphere, mesosphere, and lower thermosphere. This work was partly supported by Grant No. 18-29-03022 from the Russian Foundation for Basic Research. СОЛНЕЧНЫЕ ПРОТОННЫЕ СОБЫТИЯ В ПРИРОДНЫХ АРХИВАХ: ПРОБЛЕМЫ ИЗУЧЕНИЯ И ФИЗИЧЕСКИЕ ОГРАНИЧЕНИЯ Л.И. Мирошниченко ИЗМИРАН, НИИЯФ МГУ На современном методическом и физическом уровне критически рассматривается концепция экстремальных солнечных событий (ЭСС), сформированная на базе всех имеющихся (прямых и косвенных) данных о солнечных космических лучах (СКЛ), или о солнечных протонных событиях (СПС). Особое внимание уделено недавним (и продолжающимся) спорам о достоверности, происхождении и свойствах события AD1859 (событие Кэррингтона) по косвенным нитратным данным, а также событий AD775, AD994 и 3372 BC – по данным о космогенных изотопах. Несмотря на существующие неопределённости в оценках флюенса протонов с энергией выше 30 МэВ, все СПС описываются единой функцией распределения, по крайней мере, при нынешнем 162 уровне солнечной активности (СА). Показано, что экстремально большие потоки (флюенсы) СКЛ подчиняются вероятностному распределению с резким завалом в области больших флюенсов (т.е. в области малых вероятностей). Эти результаты могут быть пригодны для периодов с другими уровнями СА в прошлом и/или будущем. UPDATING 'CLASSICAL-PHYSICS': EXPERIMENTAL PROOF OF BOTH NON-EXISTENCE OF EMPTY SPACE PHOTONS MOVING THROUGH IT K. Mocnik Space Research Institute A 'Terrestrial Aberration' (TA) method of measuring the Earth's absolute velocity in contrast to the Stellar-Aberration (StA) has been proposed by Michelson and Morley in the Supplement of their 1887- paper, ignored hitherto. TA only is observable if light has been reflected by a mirror in the laboratory. Both, the historical null-result in the Interferometer-Experiment of Michelson and Morley in conjunction with our ether-drift measurement did unequivocally prove that the "longitudinal-length-contraction" as well as the "Photon", and the "empty space", aren't elements of physical reality. An innovative narrative is proposed telling that the null-result only did prove the wave view of light propagation in the 'ether', rejecting the 'moving-photon' view of light, if and only if all classical principles (a) Huygens, b) Aberration, and c) Doppler) are analyzed on the unifying fundamentals of Euclidean Geometry, thus, providing a basical update of 'Classical Physics', thus, restoring Maxwell's >ether<. NEW EVIDENCE OF SOLAR INFLUENCE ON CLIMATE OF NORTH ATLANTIC AND NORTHERN FENNOSCANDIA Ogurtsov M.G.1,2, 2 Jungner H.3 1 – Ioffe PhTI 2 – Pulkovo Observatory 3 – University of Helsinki email [email protected] Eight proxy and direct indices of: (a) summer climate in Fennoscandia, (b) sea surface temperature in the North Atlantic, (c) solar activity were analyzed over the last 3-5 centuries. New evidences of a link between solar activity, North Atlantic sea surface temperature and summer temperature in Northern Fennoscandia were obtained using novel and improved data records. It was shown that this relationship is rather complex and depends on the timescale considered. Possible physical mechanisms of the revealed connection were discussed. No relationship between activity of the Sun and summer temperature in Eastern Fennoscandia was found. 163 TWO TYPES OF THE MAGNETOSPHERE RESPONSE TO THE INTERACTION WITH INTERPLANETARY SHOCKS IN THE GEOMAGNETIC PULSATIONS PSC Parkhomov V.A.1, Yahnin A.G.2, Borodkova N.L.3, Tsegmed B.4, Tero Raita5, Khomutov S.Y.6, Pashinin S.Y.7, Chilikin V.E.1, Mochalov A.A.2 1Baikal State University, Irkutsk, Russia 2Polar Geophysical Institute, Apatity, Russia 3Institute of Space Research, Moscow, Russia 4Institute of Astronomy and Geophysics of the Academy of Sciences of Mongolia, Ulan – Bator, Mongolia 5 Sodankyla Geophysical Observatory, Finland 6Institute of Cosmophysical Research and Radio Wave Propagation, FEB RAS, Paratunka, Kamchatka, Russia 7Institute of Solar-Terrestrial Physics SB RAS, Irkutsk, Russia e-mail: [email protected] Results of the study of 30 events of interplanetary shocks - magnetosphere interaction for the period 2011 - 2015 are presented. We found two types of the geomagnetic response. During 20 sudden storm commencement (SSC) cases occurred under interplanetary shock wave (ISW) with velocity <500 km/s and dynamic pressure jump < 10 nPa on its front, the shocks were accompanied by geomagnetic pulsations Psc 1-5. In 10 SSC cases, initiated by the ISW propagating with velocity > 500 km/s and dynamic pressure jump on its front > 10 nPa, a kind of precursor of SSC was revealed, which is a short duration (3 ÷ 20 s) burst of geomagnetic pulsations in the frequency range of 0.2-11 Hz. On the ground, the burst of geomagnetic pulsations was observed globally, that is, in different local times and different latitudes. On spectrograms obtained at different locations, the burst often exhibits a resonant structure (intermittent increases and decreases of the spectral power at almost multiple frequencies). We suggest that the resonant structure could be associated with the ionospheric Alfven resonator. It is shown that the bursts are observed just before the sharp increase in H - component of the magnetic field on the ground; this is why it can be considered as the precursor of the SSC. On the basis of the analysis of the event of 22 June 2015 we present detail data confirming the presence of a precursor of the sudden magnetic impulse (SI) caused by a powerful ISW and developing during the main phase of the geomagnetic storm. A precursor in the form of a train of oscillations (broadband pulse) with a falling frequency in the range 0.25 ÷ 11 Hz with duration of ~ 20 s, having a resonance spectrum structure, is detected globally at 18:33:27 UT by a network of induction magnetometers. No significant phase delay of the signals in four frequency bands was detected at widely separated observatories. It is suggested that the pulsations could be excited in the Earth - ionosphere waveguide by a pulse of the electric field which occurred in the ionosphere as consequence of the short-time impact of the ISW on the magnetosphere. 164 LOCALIZATION OF IONOSPHERE SOURCES OF HIGH-LATITUDE GEOMAGNETIC PULSATIONS IN 2D FIELD DISTRIBUTIONS Petlenko A.V.1 1 – Saint-Petersburg Branch of Institute of Terrestrial Magnetism Ionosphere and Radio-Wave Propagation RAS (SPbF IZMIRAN) The magnetic field of high-latitude pulsations is determined mainly by the configuration of ionosphere Hall currents, which can be specified by a curvilinear coordinate grid. This grid is represented by lines of constant level and isolines of Hall currents, which can be found knowing the positions of the projection points on the ionosphere of magnetosphere field-aligned currents, as well as their direction and intensity. The configurations have been examined are initiated by a system of three field-aligned currents and reproduce well the observed types of peculiarities of the 2D distributions of the magnetic field of pulsations. The possibility of determining the intensities of field-aligned currents and their projections to the ionosphere according to the experimentally constructed distributions of the magnetic field components is discussed. It is shown that the location of the peculiarities of vertical component and changes in the curvature of isolines of horizontal component modulus of magnetic field make it possible to localize the projections of field-aligned currents and changes in their intensities during periods of pulsations’ activation, in particular, to estimate the position of the boundaries of the plasmapause region. PITCH-ANGLE DIFFUSION OF ENERGETIC PROTONS UPON THEIR INTERACTION WITH EMIC WAVES: COMPARISON OF THEMIS DATA ON WAVE SPECTRA AND ENERGETIC PARTICLES Popova T.A.1, Lyubchich A.A.1, Demekhov A.G. 1,2, Yahnin A.G.1 1 - Polar Geophysical Institute, Apatity, Russia 2 - nstitutte of Applied Physics, Nizhny Novgorod, Russia We analyze several cases of THEMIS spacecraft observations of EMIC waves in proton, He+, and O+ frequency bands in various local time sectors and L shells. We selected the events during which the energetic proton precipitation was observed by low-orbiting POES spacecraft in the conjugated region. By using the data on the spectral intensity of EMIC waves, the geomagnetic field, and the plasma density we calculated the pitch-angle diffusion coefficients of energetic protons for various energies and pitch- angles. The calculations were performed under the assumption that the ambient plasma consisted of three ion species, i.e., protons, He+, and O+ ions. The results of calculations were compared with the measured pitch-angle distributions of energetic protons in the magnetosphere and with the energy of precipitated protons. On the whole, these parameters of energetic protons are in agreement with those which can be expected on the basis of the calculated pitch-angle diffusion coefficients. 165 THE LATITUDE AND LONGITUDE DISTRIBUTIONS OF COSMIC RAY CUTOFF VARIATIONS DURING THE MAIN PHASE OF THE MAGNETIC STORM IN NOVEMBER 2003 Ptitsyna N.G., Demina I.M., Danilova O.A., Tyasto M.I. St-Petersburg Filial of Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation (SPbF IZMIRAN) e-mail: [email protected], [email protected] Cosmic rays pass through the magnetosphere and are affected by magnetospheric magnetic fields, which cause changes in the cosmic ray geomagnetic cutoff rigidities GCR (geomagnetic thresholds) and asymptotic directions of particle arrival during disturbances in the solar wind and magnetosphere. The geomagnetic cutoff is the threshold rigidity below which the particle flux is zero due to geomagnetic shielding. Using a method for tracing charged particle trajectories we determined cutoffs numerically in the Tsyganenko magnetospheric magnetic field model TS01 during the main phase of the geomagnetic storm on 20 November, 2003. We computed cutoffs on a 5ºx15º latitude-longitude grid at 20:00 UT when Dst reached the minimum, and cutoffs in the main geomagnetic field (IGRF 2000 model interpolated for the same moment). It is found that during the storm peak there is a suppression of GCR (ΔR) at low and middle latitudes in comparison with cutoffs in the main magnetic field up to 1,8 GV. Global distribution of GCR demonstrates North-South and day-night asymmetries. In the day sector in the northern hemisphere maximum ΔR occurs at a latitude of ~ 40° and in the southern hemisphere at a latitude of ~ 60 º. In the night sector in the northern hemisphere maximum ΔR occurs at a latitude of ~ 55° and in the southern hemisphere at the latitude of ~ 45°. The observed magnetospheric effects in the distribution of ΔR are due, apparently, to the dominance of partial ring current which develops at the peak of the storm. Significant reduction of geomagnetic thresholds on middle and low latitudes has contributed to the precipitation of additional flux of cosmic ray particles into the Earth's atmosphere that could be responsible for the low- and midlatitude auroras, widely observed during this magnetic storm. THE CONTRIBUTION OF THE EARTH'S MAIN MAGNETIC FIELD VARIATIONS TO AURORAL ACTIVITY IN 1600-1909 Ptitsyna N.G., Demina I.M., Tyasto M.I. St-Petersburg Filial of Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation (SPbF IZMIRAN) Aurora borealis have been observed with the unaided eye for centuries; therefore, they are an irreplaceable instrument for the study of solar-terrestrial relations and their variations. The number of observed aurora events can be a measure of the numerical parameters of the solar activity, for instance Wolf numbers W, for epochs in which they were not instrumentally defined. The yearly number of observed auroras N depends both on the solar activity and on the configuration and strength of the main Earth’s magnetic field caused by internal sources. We assessed the contribution of internal sources of geomagnetic field to the secular variation of low-and mid-latitude aurora occurrences in 17-19 centuries. For this we have used coefficients of spherical harmonic analysis – the gufm1 model, making it possible to calculate the Earth’s main magnetic field components in 1600-1909. It is obtained that changes in the main dipole magnetic moment MM, in 1600-1909 are antiparallel to variations of yearly aurora numbers N; correlation coefficients are -0.6 -0.8. An empirical model of N as a function of MM was constructed. We found that in certain periods auroral activity could be influenced greatly by shielding effects of 166 geomagnetic field. In particularly, 11-year cycles of solar activity index W are not consistent with 11-year cycles of N during 1700-1775, and MM influence is responsible for this disagreement. Considering the contribution of MM improves correlation between N and W. Minimum of N values around 1760 (Silverman minimum) is observed at maximum of solar activity and it seems to be related solely to a MM increase at that time. The sharp jump in the value of the magnetic moment of the Earth in 1795-1830, contributes considerably to the decrease of observed auroras during the Dalton minimum. DIURNAL VARIATIONS OF THE BOTTOM EDGE OF THE IONOSPHERE DURING THE PROTON PRECIPITATIONS ON AND AFTER 29 SEPTEMBER, 1989 G. F. Remenets 1, M. I. Suhovey1 , V. A. Shishaev 2 1 - Saint-Petersberg State University, Saint-Petersburg, Russia 2 - Polar Geoghysical Institute, Apatity, Murmansk reg., Russia Thirty years ago a self-consistent method for solution of an inverse VLF problem in non-stationary radio path conditions was developed, and it was used for an analysis of 3 different VLF disturbances on 29 September 1989: an ultra-energetic relativistic electron precipitation (04:00 -10:00 UT ), SID at 11:00 UT and a proton precipitation (one of the most powerful event of this type for 70 years ) [1], which began at 12:00 UT. Its analysis was stopped at 17 UT [2]. The purpose of the present report is to analyze the development of this precipitation during several days after in the terms of electric conductivity of lowest ionosphere fringe. The named conductivity is characterized by 2 parameters: by an effective height h(t) and by a value of reflection coefficient module R(t, ( h)) for first ionosphere ray in a model of effective waveguide with h. The argument of complex R(t, ( h)) is equal to for sliding angles of ray incidence and for a middle working frequency 12.1 kHz. Our work is bounded by sunset hours (15:30 – 18:30 UT). For this time the most “criminal” supposition is done: at every time moment a model waveguide is homogeneous along the radio path. Our estimation has shown that the corresponding systematic error is comparable with the apparatus phase error of the experimental data used (1 mcs). We compared quantitatively the daily variations of solar proton fluxes, which began on September 29, 1989, 12:00 UT, with the sunset changes of VLF signals for a completely auroral radio path Northern Norway - the Kola Peninsula (Aldra - Apatity). For realization of this purpose we have used the satellite data, the experimental VLF data of the Polar Geophysical Institute of the Kola Science Center, RAS, Apatity, Murmansk region and a self-consistent method of a VLF inverse problem solving [2]. The pointed method for an analysis of VLF daily variations without the precipitations was used earlier. We have established the following: i) The presented graphs on Fig. 1 give an error estimate of the method by comparing the analysis of sunset VLF variations for the positive direction of time (solid lines) with the analysis for the negative direction of time (dashed lines). Each of these analyses, based on a solution of inverse VLF problem by self-consistent method and which did not use any geophysical data, was fulfilled independently. ii) With the change of proton flux density in the period from September 29 to October 2, 1989 the daily variation of the effective height h at sunset changed from 5 km on September to 10 km on October and the reflection coefficient of first ionospheric ray at a sunset was constant. In this date period a value of effective altitude changed from 47 km to 54 km at 15:00 UT, from 52 to 64 km at 19:00 UT and a value of reflection coefficient has changed from 0.8 to 0.6. iii) From October 3 to October 5, the proton flux density has not yet come to its undisturbed value but has seriously weakened significantly. 167 In a real wave guide there is none ray mode because of wave length comparability with the altitude scale of inhomogeneity of electric conductivity, but it was shown numerically several decades ago that an effective height h was placed inside the significant lay of conductivity for radio wave reflection. Roughly speaking the h is an analog of weight center for a solid. Fig.1.The sunset changes of electric atmosphere properties before (Sept. 28) and during the solar proton precipitations in the terms of effective height (altitude) h. References: [1] Miroshnichenko Leonty, Curt A. de Konong, R. Perez-Enriques. Large solar event of September 29, 1989: Ten years after // Space Science Reviews. Feb 2000. Vol. 91. Issue 3. P. 615-715. [2] Remenets, G. F. and M. I. Beloglazov. Dynamics of an auroral ionospheric fringe at geophysical disturbances on 29 September 1989 // Planet. Space Sci. 1992. Vol.40. P. 1101-1108. BALLOONING INSTABILITY OF COUPLED MHD MODES IN 2D MODEL OF THE MAGNETOSPHERE Rubtsov A.V.1, Mager P.N.1, Klimushkin D.Yu.1 1 – Institute of Solar-Terrestrial Physics SB RAS, Irkutsk, Russia In this study we investigates the conditions of the ballooning instability of the coupled Alfvén and slow magnetoacoustic modes in the dipole model of terrestrial magnetosphere with taking into account inhomogeneity of plasma and magnetic field in the direction along the magnetic field lines. The instability is found to develop on the slow magnetoacoustic oscillation branch, but necessarily with taking into account the coupling with the Alfvén mode. The symmetric (with respect to the magnetic equator) modes more unstable than antisymmetric ones. For the symmetric case, the instability threshold depends on plasma compressibility: the finite sound velocity raises the instability threshold. For all other equal conditions, the instability threshold decreases with the decrease of the field line curvature radius on the equator. Thus, in the geomagnetic tail the instability has more chances to develop than in the region with the dipole field lines. This study was supported by the Russian Science Foundation under grant 18-17-00021. 168 PC5 COMPRESSIONAL EVENT OBSERVED WITH THEMIS: SPATIO- TEMPORAL STRUCTURE, WAVE-PARTICLE INTERACTIONS Rubtsov A.V.1, Agapitov O.V.2, Mager P.N.1, Klimushkin D.Yu.1, Mager O.V.1 1 – Institute of Solar-Terrestrial Physics SB RAS, Irkutsk, Russia 2 – Space Science Laboratory, University of California, Berkeley, CA, USA The compressional high-m Pc5 wave associated with the localized hot proton injection was observed by THEMIS mission spacecrafts in the dusk sector of the magnetosphere at L ~ 10. The wave was propagating in energetic proton drift direction with azimuthal wave number m ~ -60. The transverse magnetic field of the wave was primarily poloidal. The pulsation followed two consecutive substorms: the cloud of energetic particles comprised of the lower energy protons from the earlier substorm and higher energy protons from the subsequent one. The clear signatures of the wave-particle drift resonances as proton fluxes modulation by the wave were observed. The wave frequency was about two times less than the corresponding Alfvén wave eigenfrequency on the same L-shells and there is a strong dependence of the wave’s frequency on the m number. The supposed generation mechanism is the gradient instability. The increase of the particle energy from the Earth constitutes the conditions for the gradient instability of the drift compressional mode, since for the Alfvén mode the particle energy must decrease. Thus, we conclude that the observed wave was drift compressional mode generated by the gradient instability. This study was supported by RFBR under grant 16-05-00254. ALFVÉN WAVES AS A DRIVER FOR MAGNETOSPHERIC DYNAMICS V. Semenov1, M. Kubyshkina1, I. Kubyshkin1, N. Erkaev2,3, E. Gordeev1, M. Shukhtina1, V. Sergeev1 1 – Saint Petersburg State University, Saint Petersburg, Russia 2 - Institute of Computational Modelling SB RAS, Krasnoyarsk, Russia 3 - Department of Applied Mechanics, Siberian Federal University, Krasnoyarsk, Russia We analyze the 11-year period of solar wind (SW) and Interplanetary Magnetic Field (IMF) data and reveal the disproportion in the distribution of the product of IMF Bx component and SW velocity vz- component for different signs of IMF Bz . This disproportion can be explained if we admit that about 70% of IMF Bz-component are transported to the Earth’s orbit by Alfven waves. The explanation is further supported by the fact, that the disproportion increases in the years of solar cycle maximal activity and decreases during the low solar activity years. We also show that the same unbalance in (Bx vz ) distribution grows notably before a substorm onset, with slow increase during first 40 minutes of growth phase (we use 1 hour period before a substorm onset as a growth phase for generality) and sharp increase in the last 10-20 minutes before onset. Thus, the change in sign of (Bx vz) may be treated like an additional trigger for a substorm breakup. The explanation we suggest for this phenomenon is the efficient displacement of the magnetospheric plasma sheet by both IMF Bx and SW flow vz, which move plasma sheet in the same direction if the sign of (Bx vz) is negative under negative Bz or positive under positive Bz . The displacement of current sheet, in 169 its turn, increases the asymmetry of the magnetotail and the plasma sheet and can alter the threshold of substorm instabilities. DEPENDENCE OF ENERGETIC PROTON PRECIPITATION EQUATORWARD OF THE ISOTROPY BOUNDARY ON GEOMAGNETIC ACTIVITY N. V. Semenova1, T. A. Yahnina1, A. G. Yahnin1, and A. G. Demekhov1, 2 1 Polar Geophysical Institute, Apatity, Russia 2 Institute of Applied Physics, Nizhny Novgorod, Russia e-mail: [email protected] Energetic proton precipitation equatorward of the boundary of isotropic fluxes (EPPEBIF) is the consequence of the ion-cyclotron instability (ICI) developing in the vicinity of the equatorial plane of the magnetosphere. Thus, the precipitation can be used for statistical studies of the EMIC wave occurrence. The global distribution of the occurrence rate of EPPEBIF is constructed on the basis of the data from four POES satellites that operated during July-December of 2005. The distribution exhibits the maximal occurrence on the dayside at distances behind the geostationary orbit. This agrees with the EMIC waves occurrence in the magnetosphere. It is also shown that maximal occurrence rate of the precipitations increases with the increase in the solar wind dynamic pressure independently of the geomagnetic activity level. We demonstrate that the maximal occurrence rate on the dayside increases when the geomagnetic activity changes from low to moderate, and it decreases during the higher activity. Such behavior can be explained by the effect of the two competitive processes, both of them are due to the nightside injections of energetic protons. On the one hand, the injections lead to growth of particle flux, which, in turn, causes the increase of ICI increment. On the other hand, the injections lead to the decrease of the radial gradient of the particle flux on the nightside. This results in the decrease of transverse anisotropy of energetic protons on the dayside and diminishes the ICI increment. ADVANCES IN MAGNETOTAIL MONITORING DURING SUBSTORMS Sergeev, V.A. 1, N.A. Tsyganenko1 , E.I. Gordeev1, V.G. Merkin2, M.I. Sitnov2, V. Angelopoulos3, A.V. Runov3 1- St.Petersburg State University 2- Applied Physics Laboratory, John Hopkins University 3- University of California Los Angeles Statistical analyses of magnetotail observations provides gross features of magnetotail configuration changes during substorms, but misses the individual details and variability during individual events. Recently we showed how the energetic electron observations from polar orbiting spacecraft can reveal magnetotail topology changes during strong solar electron events when the high flux of energetic 170 electrons-tracers are available. (1) For the substorm growth phase we were able to show an isolated event in which latitudinally-localized region of anisotropic 30 keV electron loss cone embedded in the isotropic solar electron precipitation was persistently observed for more than 0.5 hour by six POES spacecraft which crossed the premidnight auroral oval. Such embedded anisotropic regions were observed ~1deg poleward of the outer radiation belt boundary over 4-5 hours wide MLT sector, suggesting a persistent ridge-type BZ/j maximum in the equatorial plasma sheet at distances 15-20Re. We discuss unfrequent observation of such events taking into account recent results of global MHD simulations. (2). As regards steady magnetospheric convection (SMC) events, we analyzed a rich collection of observations during ~10 hours of strong, steady solar wind driving to show that, following a southward turning of the interplanetary magnetic field (IMF) and a subsequent 3-4 hour period of large-scale substorm related reconfigurations and plasma injections, the near-Earth magnetic configuration evolved into a non-standard type which lasted until the end of this SMC event (five hours). During that time a dipolarized region with complicated Bz landscape persisted in the midtail while the configuration was very stretched in the near tail. This was manifested as a highly depressed magnetic Bz component at geostationary orbit and as persistent non-adiabatic electron scattering at the periphery of the outer radiation belt. In addition, in situ observations suggest that a thin current sheet extended longitudinally toward the dawn terminator. In the return convection region near the terminator, observations of this azimuthal current sheet were sporadically interrupted/modulated by earthward-convecting plasma structures, either remnants of reconnection-produced plasma bubbles or flapping waves.The hybrid magnetotail configuration (dipolar in the mid-tail and stretched in the near tail) observed during this long- duration SMC event poses a challenge for empirical magnetospheric modeling. INNER MAGNETOSPHERE RECONFIGURATION DURING THE SUBSTORM GROWTH PHASE M. A. Shukhtina 1, E. I. Gordeev 1, V. A. Sergeev 1 1Dept.of Earth’s Physics, Saint-Petersburg State University, St. Petersburg, Russia email: [email protected] It is well known that during the substorm growth phase magnetotail magnetic field stretching and plasma sheet thinning are observed. For several decades this effect was entirely attributed to open magnetic flux accumulation (OMFA) in the tail lobes, leading to tail flaring increase, magnetotail pressure rise and plasma sheet thinning. However, recently Hsieh and Otto (2014) proposed another scenario, including closed magnetic flux depletion (CMFD) in the inner magnetosphere. This effect results from enhanced convection in the inner magnetosphere, caused by electric field propagating from the dayside reconnection site. Hsieh and Otto (2014) tested this mechanism on regional 3-D MHD model, whereas Gordeev et al. (2017) used self-consistent global MHD simulations. Gordeev et al. (2017) confirmed the importance of CMFD process which, according to their estimates, amounts ~30% of OMFA value. In our work we tried to estimate the CMFD and OMFA values experimentally based on simultaneous observations of Cluster and Geotail spacecraft in the inner ( 171 Hsieh, M.-S., and A. Otto (2014), The influence of magnetic flux depletion on the magnetotail and auroral morphology during the substorm growth phase, J. Geophys. Res. Space Physics, 119, 3430–3443, doi:10.1002/2013JA019459. Gordeev, E., V. Sergeev, V. Merkin, and M. Kuznetsova (2017), On the origin of plasma sheet reconfiguration during the substorm growth phase, Geophys. Res. Lett., 44, doi:10.1002/2017GL074539. RING CURRENT PROTON DYNAMICS DRIVEN BY WAVE-PARTICLE INTERACTIONS DURING A NONSTORM PERIOD Smolin S. V. Siberian Federal University, Department of Theoretical Physics, Krasnoyarsk, Russia It is used correlated observation of enhanced electromagnetic ion cyclotron (EMIC) waves and dynamic evolution of ring current proton flux collected by Cluster satellite near the location L = 4.5 during March 26-27, 2003, a nonstorm period (Dst > -10 nT). Energetic (5-30 keV) proton fluxes are found to drop rapidly (e.g., a half hour) at lower pitch angles, corresponding to intensified EMIC wave activities. As mathematical model is used the non-stationary one-dimensional pitch angle diffusion equation which allows to compute theoretically density of phase space or pitch angle distribution of the charged particles in the Earth’s magnetosphere. The model depends on time t, a local pitch angle and several parameters (the mass of a particle, the energy, the McIlwain parameter, the magnetic local time or geomagnetic eastern longitude, the geomagnetic activity index, parameter of the charged particle pitch angle distribution or the pitch angle distribution anisotropy index but is taken for the 90 degrees pitch angle at t = 0, the lifetime due to wave-particle interactions). This model allows to estimate also for different geophysical conditions a lifetime due to wave-particle interactions. It is shown, that EMIC wave can yield decrements in proton flux within 30 minutes, consistent with the observational data. The good consent is received. The presented model and results of numerical calculations will promote the further understanding of ring current proton dynamics driven by wave- particle interactions under different geomagnetic activities. THE SIMPLE ANALYTICAL DESCRIPTION FOR RELATIVISTIC (>2 MEV) ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT Smolin S. V. Siberian Federal University, Department of Theoretical Physics, Krasnoyarsk, Russia It is used the observation of relativistic (>2 MeV) electron fluxes combined and averaged by local hour around geosynchronous orbit from 1995 to 2009 collected by GOES satellite. The flux distribution in local time (LT) peaks near noon (between 1100 and 1200 LT) and sees its minimum near midnight (between 2300 and 0000 LT). The average value of this flux distribution that is the daily average can be significantly less than the maximum flux. As the analytical description is offered the simple formula for definition of a perpendicular (for a pitch angle of 90 degrees) integrated flux of relativistic (>2 MeV) electrons at geosynchronous orbit which 172 depends on the magnetic local time (LT) or geomagnetic eastern longitude, the McIlwain parameter L, the geomagnetic activity index Kp and the perpendicular integrated flux of relativistic (>2 MeV) electrons but taken at LT = 0 hr. This formula can be considered as the first approximation for any perpendicular integrated flux in a geosynchronous orbit, when L = const and Kp = const or Kp approximately const. Comparison of analytical dependence with experimental data of satellite GOES in a geosynchronous orbit of the Earth is made. The good consent is received, especially with 0000 LT up to 1100 LT and with 1800 LT up to 2400 LT. GEOMAGNETIC DISTURBANCES WITH SUDDEN AND GRADUAL COMMENCEMENTS IN 1869-1954 ACCORDING TO OBSERVATORY DATA AND CATALOGS OF STORMS Sergey Sokolov1, Vadim Soldatov1, Vladimir Koshelevsky1 1 – SPbF IZMIRAN email: [email protected] Observations of variations in the geomagnetic field and the magnetic activity indices based on these observations are the only source of information about "geomagnetic weather" in the late 19th – first half of the 20th century. The aa indices, calculated from 1868, allow us to distinguish periods of magnetic storms of different magnitude and duration. Information on disturbances can be obtained directly from observational data at observatories, as well as from storm catalogues compiled from local observations on some of them. To understand how the geomagnetic activity changed during eight 11-year solar cycles (1869-1954), we used the magnetograms and the catalogues of storms. On the basis of aa-indices we selected periods during which the maximum value of aa-index (aamax) exceeded 30 (Kpa_max > 3) for more than three hours. These periods were considered disturbed, and it was taken into account that within themselves they could have quiet intervals with a duration of up to 18 hours. Depending on the values of aamax, each event was assigned a corresponding rank. Data on sudden commencement (SC) storms helped to distinguish storms with SC among selected disturbances. The resulting sampling divides the disturbances by magnitude and by type of commencement – sudden or gradual (GC). A comparison of the obtained list with the catalogs data showed that the latter, as a rule, included disturbances with aamax > 95 (Kpa_max > 5) only; smaller events were not included. Some storms in the directory wrongly attributed to disturbances with GC, not SC. This is indicated by the data of the endorsed list of SCs (http://www.obsebre.es/en/rapid) and our review of the magnetograms of the observatories of St. Petersburg and Pavlovsk; they show almost all SCs from the above list. Our catalog includes 4620 storms: 1340 with SC and 3280 with GC. Using it, we found out how the number of storms of different magnitude (with SC and GC) changed depending on the number of sunspots and at different phases of solar cycles. It is shown, in particular, that during the period considered there was a faster growth of storms with GC than with SC. 173 SPATIAL-TEMPORAL CHARACTERISTICS AND PHYSICAL NATURE OF THERMAL ANOMALY DIAGNOSED BY THE EISCAT RADAR WITHIN THE DUSTED NIGHTSIDE AURORAL DYNAMO LAYER E.E. Timofeev,1 S.L. Shalimov,2,3 M.K. Vallinkoski,4 J.Kangas4 1 Admiral Makarov State University of Maritime and Inland Shipping, Saint-Petersburg, Russia. 2 Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia 3 Space Physics Institute of the Russian Academy of Sciences, Moscow, Russia 4 Space Physics Department of the University of Oulu, Oulu, Finland In the present study we analyze parameters of the lower ionosphere, measured by the EISCAT radar facility at the magnetic zenith of Tromsø auroral observatory during the ERRRIS campaign. Data used consists of 19 different nights of observations and includes about 2000 simultaneous measurements of 5 parameters of the dynamo layer plasma at each of the three altitude levels:, 106, 110 and 115 km. Namely: the temperatures of the ions (Ti) and electrons (Te), electron density (Ne), modulus and azimuth of the ionospheric electric field vector (E-field). The level of meteoric dust in the lower ionosphere was monitored according to the IMO website. The subject of the analysis is further study of the spatial- temporal characteristics of the temperature anomaly (TA= (Ti - Te) described earlier, for example, in our report to the COSPAR-2014. The main feature of the anomaly contradicts all modern models of physics of the lower ionosphere. Namely: Te is (50-100 K) lower than Ti. The analysis showed that 1) 75% and 25% of the ERRRIS data corresponds to modulus E-field that is below and above the threshold of the Farley-Buneman (FB-instability), respectively 2)The altitude profile of the thermo-anomaly reaches a maximum at an altitude of 106 km. Wherein, its average value (TA=~50 K) is equal to its STD value. While the E-field module was in the range of 20-25 mV/m, that is just below to the normal threshold of the FB-instability; 3) At an altitude of 110 km, the average value of TA is no more than (~ 20 K), which is almost twice as low as STD of T.A. at this altitude. The maximum is achieved with smaller values of the E-field compared with a height of 110 km: namely, in the range 15-20 mV/m. At each of the heights (106 and 110 km), further growth of the E-field module above the FB-turbulence threshold leads to explosive growth of the STD values, i.e. to the rapid destruction of the thermo-anomaly. 4) A rare single interval of radar measurements lasting no more than 15-20 minutes in the event of 01.04.1988 demonstrated the fundamental possibility of forming a thermo-anomalous structure at altitudes near the lower edge of the heights of the dynamo layer. Namely, at an altitude of 102 km. At the same time, the values of the thermal anomaly (from 20 to 60 K) were not destroyed even under conditions of growth of the E-field modulus up to 35 mV / m. 5) The constant anti-correlation of the temporal variations of the ion (dTi) and electron (dTe) temperatures on the time scale of the pulse duration of the EISCAT radar (~90 C) was detected under the conditions of the thermo anomaly. The correlation coefficient was calculated from samples of 16 to 25 consecutive radar pulses. Near the threshold of the FB instability (15-25 mV/m), this coefficient reaches a maximum near (0.9), and then falls sharply to zero with a further increase in the E-field. 6) As it turned out, there are both upper and lower limits of electron density, for which the magnitude of the thermo-anomaly is already close to zero. The lower limit of the Ne density is ~ 1.5x104/cm3. The values of the limiting electron density are different for altitudes of 106 and 110 km. Namely: ~ 25 and ~ 35x104/cm3 for heights of 106 and 110 km respectively. The physical nature of the thermo-anomaly is interpreted on the basis of the electron cooling effect known from the theory , as well as from experiments in nonideal laboratory plasma, due to the 174 precipitation of the "hot tail of the electron distribution function" on the particles of metallic dust. Under the conditions of meteor stream intrusions, the plasma of the night auroral dynamo layer becomes a three- component: ions, electrons and negatively charged metal macro- particles of meteoric dust. At the same time, the overwhelming majority of the energy of a dusty plasma is concentrated in dust particles. Therefore, under such adiabatic conditions, antiphase variations of the electron and ion temperatures are observed. CRITERIA FOR VULNERABILITY OF POWER TRANSFORMERS ELECTRIC POWER SYSTEMS WITH PERTURBATION OF COSMIC WEATHER Vahnina V.V., Kozub A.A. Dubinin M.V. Togliatti State University During sudden changes in space weather, which are accompanied by increased geomagnetic activity, between grounded neutrals of power transformers of electric power systems (EPS) a potential difference arises that causes high voltage and phase conductors of the quasi-permanent current (QPC) transmission lines to flow along high-voltage earthed windings. The latter is commonly called a geo-induced current [1]. The frequency of the QPC is not higher than 0.1 Hz, which is many times less than the nominal frequency (50 Hz) of the mains voltage. The magnitude of the QPC can be quite commensurate with the rated current of the power transformers of the EPS [2]. The main effect of QPC with increased geomagnetic activity in the unilateral saturation of the magnetic system of power transformers. In this case, non-sinusoidal magnetizing currents increase many fold. This is equally dangerous, both for power transformers, and for additional heating, windings, magnetic circuit, oil, structural elements, and for regimes EPS, since the consumption of reactive power is increasing and the quality of electric power in the electric network is deteriorating [3]. Therefore, the actual task is to adequately assess the degree of influence, QPC caused by space weather perturbations, to the depth of unilateral saturation of power transformers with different design of the magnetic system-rod, armored rod and armor design. Modeling of magnetic fields under the influence of QPC on power transformers, taking into account the design of the magnetic circuit, is performed in the program FEMM 4.2 [4]. It is shown that on power transformers with a rod structure of a magnetic system, a "strong" effect can only be quasi-permanent currents whose magnitude is higher than the rated current of the high-voltage winding. The intensity of the effect of cosmic weather perturbations on the magnetic system of power transformers with different design of the magnetic system is suggested to be estimated by the saturation coefficient ks. The saturation coefficient ks characterizes the intensity of magnetization of the structural elements of the magnetic systems of the power transformers of the EVC from the value of the magnetizing current IQPC. It is proposed, for power transformers with the armor design of the magnetic system, the saturation coefficient to be assumed equal to unity ks = 1. For transformers with armored rod structure of the magnetic system, ks = 0.4 ÷ 0.5. Power transformers with a rod structure of a magnetic system are practically not affected by the geo-induced QPC, and for them the saturation coefficient is zero ks = 0. LITERATURE 1. Boteller D.H. The influence of geomagnetic inductive current B.C. Hydro 500 kV - System. IEEE Trans. Power Deliv., 1989, vol. 4, No. 1. P.818-823. 175 2. Pirzhala R. The influence of the interaction of stations on the calculation of geomagnetically induced currents in electric power transmission systems. Planet Earth Planet, 2008, №60. P.743-751. 3. Kappenman J.G. Geomagnetic storms and their impact on the US electrical network. Metatech Corporation 358 S. Fairview Ave., Suite E Goleta, CA 93117, January 2010. 197 pp. 4. Meeker D.C. FEMM 4.2. Magnetostatic teaching aid. URL: http://www.femm.info/Archives/doc/tutorial-magnetic.pdf. MANIFESTATION OF 60-YEAR CLIMATIC CYCLE IN CORRELATION LINKS BETWEEN SOLAR ACTIVITY AND THE LOWER ATMOSPHERE CIRCULATION Veretenenko S.V., Ogurtsov M.G. Ioffe Institute Temporal variability of correlation links observed between characteristics of the lower atmosphere and solar activity on the multi-decadal time scale remains one of unresolved problems of solar-terrestrial physics. In this work we continue studying possible reasons for this variability. Temporal behavior of correlation coefficients between troposphere pressure at extratropical latitudes and sunspot numbers was compared with long-term changes in frequency of occurrence of large-scale circulation forms according to Vangengeim-Girs classification, as well as with the evolution of the stratospheric polar vortex and global temperature anomalies. It was shown that a roughly 60-year periodicity revealed in the amplitude and sign of solar activity/galactic cosmic ray (SA/GCR) effects on extratropical cyclogenesis intensity [1] is closely related to large-scale circulation epochs. The detected sign reversals of correlation links between troposphere pressure and SA/GCR variations were found to coincide with turning points in the evolution of the main forms of atmospheric circulation which are accompanied by transitions of the polar vortex from its strong state to a weak one and vice versa. This allows suggesting that the detected correlation reversals are caused by changes of troposphere-stratosphere coupling associated with changes of the vortex strength. It was shown that the changes of the polar vortex state and the corresponding changes in large-scale circulation epochs may be related to global temperature anomalies which also reveal a roughly 60-year variation. It was suggested that a possible reason for this temperature variation may be long-term changes of total solar irradiance. Veretenenko S., Ogurtsov M., 2012. Regional and temporal variability of solar activity and galactic cosmic ray effects on the lower atmosphere circulation. Adv. Space Res. 49(4), 770–783. LONG-TERM NORTH-SOUTH ASYMMETRY OF THE SOLAR MAGNETIC FIELD Vokhmyanin M., Zolotova N., and D. Ponyavin St Petersburg University Various solar magnetic field manifestations are north-south asymmetric in amplitude and phase. We analyze the offset of the heliospheric current sheet (HCS) from the ecliptic plane and sunspot areas over 176 19 and 20 centuries. We found that both parameters experience simultaneous changes in terms of dominating hemisphere around solar activity cycles 14-15 and 19-20. The same phenomenon is observed in the differential rotation velocity. We suggest that these north-south asymmetries originate from the same global source and vary regularly with nearly centennial periodicity. RECONSTRUCTION OF PARAMETERS OF THE SOLAR ACTIVITY IN XVII CENTURY N. Zolotova1, M. Vokhmyanin1 1 - Saint-Petersburg state university [email protected]; [email protected] Records on the solar activity in the distant past provide an important information on the eventual crucial changes in the physical parameters of the solar activity during the so-called Grand-minima. In this work we present the state of art of the sunspot activity reconstruction from historical observations by Galilei, Harriot, Scheiner, Gassendi, and Hevelius from 1610 to 1644. Behaviour of the butterfly diagram, sunspot areas and numbers, differential rotation, quality of observations are analysed and compared to the modern ones. VERIFICATION OF THE OMNI DATABASE USING PC INDEX Vokhmyanin M.V., Stepanov N. A., Sergeev V. A 1 - St. Petersburg State University, Earth Physics Department, St. Petersburg 198504, Russia 2 - Arctic and Antarctic Research Institute, St. Petersburg, Russia. [email protected] [email protected] [email protected] OMNI database of solar wind parameters is compiled from ACE, WIND, GEOTAIL and IMP8 measurements which are time-shifted to the bow shock nose. In order to check the reliability of the OMNI data, we compare EKL = VBxysin2(θ/2) from the OMNI data and according to GEOTAIL measurements made near the subsolar point (within 5 Re from the GSE X axis). PC index of geomagnetic activity is designed as a proxy of EKL and can serve as another indicator of OMNI data quality. We analyze correlation between 1-min EKL and PC index variations within 2-hour intervals. The correlation analysis fails when the amplitude of the EKL variation is low, therefore we consider intervals with ΔEKL greater than 1.5 mv/m. For about 15% of intervals high correlation between OMNI and GEOTAIL EKL corresponds to low correlation between OMNI EKL and PC index. For the rest majority of the analyzed cases the higher (lower) the OMNI-GEOTAIL correlation the higher (lower) the OMNI-PC correlation. Therefore using the PC index we can filter intervals of “good” OMNI data corresponding to the solar wind near the bow shock nose. Parameters of the interplanetary magnetic field and solar wind plasma during periods of 163 isolated substorms were have been investigated. It is shown that the solar wind velocity V and plasma density N remain approximately constant for at least 3 h before the onset of the substorm onset expansion phase То and 1 h after То. On average, the velocity V of the solar wind exhibits a stable trend toward anticorrelation with its density N over the whole data array. However, the situation is different if the values of V and N are considered with respect to the intensity of substorms observed during that period. These substorms appear on the background of an increase both in the solar wind velocity and solar wind 177 plasma density levels, which is observed in the substorm maximum with an increase in the magnitude of the AL magnetic activity index. With the growth of substorms intensity, quantified as the maximum absolute value of AL index, there observed an increase in both the solar wind plasma velocity and density, at which these substorms appear. It has been is found that the magnitude of the solar wind dynamic pressure P is closely related to the magnetosphere energy load defined as averaged values of the Kan-Lee electric field EKL and Newell parameter dФ/dt averaged for 1 h interval before То. The growth of the dynamic pressure is accompanied by an increase in the load energy necessary for substorm generation. This interrelation between P and values of EKL and dФ/dt is absent in other, arbitrarily chosen periods. It is believed suggested that the processes accompanying increasing dynamic pressure of the solar wind result in the formation of magnetosphere conditions that increasingly impede substorm generation. Thus, the larger is P, the more solar wind energy must enter the Earth's magnetosphere during the period of the growth phase for substorm generation. This energy is later released during the period of the substorm expansive phase and creates even more intense magnetic bays. RELATIVISTIC ELECTRON PRECIPITATION AND GEOMAGNETIC ACTIVITY A. G. Yahnin, T. A. Yahnina, and N. V. Semenova Polar Geophysical Institute, Apatity, Russia e-mail: [email protected] We considered ~1500 REP events during three 184-day (half of year) intervals for magnetically “disturbed” (2005), ”quiet” (2009) and moderately disturbed (2011) epochs. All events were divided into three groups according to criteria by Yahnin et al. [2016, 2017]. It was suggested that these groups correspond to different mechanisms of the precipitation. Each group of the REP events exhibited different percentage during the abovementioned intervals. This may mean that the relative contribution of different mechanisms to the production of precipitation from the radiation belt varies depending on geomagnetic activity. For each group the dependence of the REP occurrence rate and intensity on geomagnetic activity was investigated. It was shown that for each group the probability of the REP observation increases when geomagnetic activity grows. At the same time for each group, the REP flux does not depend of on the current geomagnetic activity. However, the average of the REP flux for some time interval was found to be proportional to mean values of the geomagnetic activity indices corresponding with this interval. 178 SIMULTANEOUS OBSERVATIONS OF EMIC AND VLF WAVES DURING MULTIPLE MAGNETOSPHERE COMPRESSIONS A.G. Yahnin1, J. Manninen2, T. Raita2, T.A. Yahnina1, E.E. Titova1, A.G. Demekhov1,3 1 Polar Geophysical Institute, Apatity, Russia 2 Sodankyla Geophysical Observatory, Sodankyla, Finland 3 Institute of Applied Physics of RAS, Nizhniy Novgorod, Russia e-mail: [email protected] A series of simultaneous EMIC and ELF/VLF wave bursts were observed onboard the Van Allen probes (VAP) during the event of multiple magnetosphere compressions on 14 Sept 2017. The bursts, which have duration and cadence of several minutes, were observed during about four hours when the spacecraft were on the day side and went through the apogee. Similar temporal structures of the emissions were detected on the ground in the Pc1 and ELF/VLF ranges by the network of induction coil magnetometers and by the ELF/VLF receiver in Kannuslehto, respectively. Combining the VAP and ground-based wave data with particle precipitation data from low-orbiting POES satellites allowed us to identify the precipitation pattern associated with both ELF/VLF and EMIC waves. This is the enhancements of precipitating >30 keV energetic electrons and protons, which are localized within the zone of anisotropic fluxes at L>4. This precipitation occupies the area around noon and has dimensions as large as 1-4 degrees in latitude and several hours in MLT. The area of the precipitation significantly varies in time. We conclude that this kind of precipitation is the result of pulsed development of the co-located ion- cyclotron and electron-cyclotron instabilities stimulated by enhancements of the transverse anisotropy of the ring current and outer radiation belt particles due to multiple magnetosphere compressions. ACCELERATION OF COLD ION COMPONENT AT THE SEPARATRICES DURING COLLISIONLESS MAGNETIC RECONNECTION. I. Zaitsev1, A. Divin1, V. Semenov1 1 – Saint-Petersburg State University We present kinetic simulations of magnetic reconnection in the presence of low-energy ion population performed with a Particle-in-cell code iPIC3D. Simulation results are compared to conventional reconnection pattern obtained with upstream plasma beta =1. We propose a model of cold ion energization by means of acceleration with normal (Hall) electric field existing at the separatrices. Cold ion component appears to be much more sensitive than the hot one to small-scale electrostatic field due to the smallness of the initial gyroradius. Electrostatic potential drop leads to outflow-directed bulk acceleration with formation of deep density cavities. Simulations with hot ion component only indicate that the potential well scatters the particles in such a case when the gyroradius exceeds the gradient scale of electric field. Test particle simulations are performed in order to study how cold and hot ions pass through the small-scale electric field inhomogeneity. The resulting ion scattering/acceleration depends on the ratio of the initial particle gyroradius to the potential well width. 179 TRIGGER REGIME OF THE MAGNETOSPHERE DYNAMICS IN THE SOLAR ACTIVITY CYCLE O.D. Zotov1, B.I. Klain2, N.A. Kurazhkovskaya3 1,2,3 Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth, Russian Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia e-mail: [email protected]; [email protected]; [email protected] The work is devoted to the study of the features of the Earth’s magnetosphere dynamics. It is shown that in each of the 11-year cycles of solar activity the dynamics of the magnetosphere activity (Ap and AL- indices) demonstrates a sharp transition (trigger mode) from the “periodic” regime (low level of broadband noise, the presence of a 27-day periodicity) to a “chaotic” (high level of broadband noise, lack of a 27-day periodicity). The goal of this work is to search of the parameter of the solar activity dynamics and/or the interplanetary medium which determines the switching of the magnetosphere regimes. We used for the analysis series of daily values of the solar activity and interplanetary medium parameters during the period of 1932 - 2016. It has been found that the dynamics of the spectral characteristics and the trigger properties of the Ap and AL indices correlate with the dynamics of the solar wind parameter β (β is ratio of the plasma pressure to magnetic pressure). It is shown that the change of the magnetosphere regime “chaos - periodicity” is determined by the β value. The “chaotic” and “periodic” regimes in the dynamics of the magnetosphere are observed at β≤1 and at β>1 respectively. We note that the level of turbulent fluctuations in the solar wind reaches its maximum values precisely at β ~ 1 [1]. Consequently, the ratio of the plasma pressure to magnetic pressure is the parameter that determines the switching regime in the magnetosphere dynamics. The change of the β in the 11-year cycle of solar activity is determined by the dynamics of the inclination angle of the magnetic dipole axis of the Sun [2, 3]. Thus, the global geoeffective parameter determining the particular features of the dynamics of the magnetosphere activity is the inclination angle of the magnetic dipole axis of the Sun to the ecliptic plane. This work was supported by Russian Foundation for Basic Research 16-05-00056, Government task 0144-2014-00116. REFERENCES 1. Chernyshov A.A., Karelsky K.V., Petrosyan A.S. Subgrid-scale modeling for the study of compressible magnetohydrodynamic turbulence in space plasmas // UFN. 2014. V. 184 (5). P. 457 - 492. 2. Livshits I.M. Obridko V.N. Variations of the dipole magnetic moment of the sun during the solar activity cycle // Astron. Rep. 2006. V. 50: 926. doi:10.1134/S1063772906110060. 3. Sokolov I. V., Bart van der Holst, Rona Oran et al. Magnetohydrodynamic waves and coronal heating: unifying empirical and MHD turbulence models // The Astrophysical Journal. 2013. V.764: 23. 13pp. doi:10.1088/0004-637X/764/1/23. 180