A Dangling Slab, Amplified Arc Volcanism, Mantle Flow and Seismic Anisotropy in the Kamchatka Plate Corner
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Kinematic Reconstruction of the Caribbean Region Since the Early Jurassic
Earth-Science Reviews 138 (2014) 102–136 Contents lists available at ScienceDirect Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev Kinematic reconstruction of the Caribbean region since the Early Jurassic Lydian M. Boschman a,⁎, Douwe J.J. van Hinsbergen a, Trond H. Torsvik b,c,d, Wim Spakman a,b, James L. Pindell e,f a Department of Earth Sciences, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, The Netherlands b Center for Earth Evolution and Dynamics (CEED), University of Oslo, Sem Sælands vei 24, NO-0316 Oslo, Norway c Center for Geodynamics, Geological Survey of Norway (NGU), Leiv Eirikssons vei 39, 7491 Trondheim, Norway d School of Geosciences, University of the Witwatersrand, WITS 2050 Johannesburg, South Africa e Tectonic Analysis Ltd., Chestnut House, Duncton, West Sussex, GU28 OLH, England, UK f School of Earth and Ocean Sciences, Cardiff University, Park Place, Cardiff CF10 3YE, UK article info abstract Article history: The Caribbean oceanic crust was formed west of the North and South American continents, probably from Late Received 4 December 2013 Jurassic through Early Cretaceous time. Its subsequent evolution has resulted from a complex tectonic history Accepted 9 August 2014 governed by the interplay of the North American, South American and (Paleo-)Pacific plates. During its entire Available online 23 August 2014 tectonic evolution, the Caribbean plate was largely surrounded by subduction and transform boundaries, and the oceanic crust has been overlain by the Caribbean Large Igneous Province (CLIP) since ~90 Ma. The consequent Keywords: absence of passive margins and measurable marine magnetic anomalies hampers a quantitative integration into GPlates Apparent Polar Wander Path the global circuit of plate motions. -
Spatio-Temporal Characteristics of Frictional Properties on The
Yamada et al. Earth, Planets and Space (2021) 73:18 https://doi.org/10.1186/s40623-020-01326-8 FULL PAPER Open Access Spatio-temporal characteristics of frictional properties on the subducting Pacifc Plate of the east of Tohoku district, Japan estimated from stress drops of small earthquakes Takuji Yamada1* , Meitong Duan2,3 and Jun Kawahara1 Abstract The east coast of the Tohoku district, Japan has a high seismicity, including aftershocks of the 2011 M9 Tohoku earth- quake. We analyzed 1142 earthquakes with 4.4 ≤ MW ≤ 5.0 that occurred in 2003 through 2018 and obtained spatio- temporal pattern of stress drop on the Pacifc Plate that subducts beneath the Okhotsk Plate. Here we show that small earthquakes at edges of a region with a large slip during the 2011 Tohoku earthquake had high values of stress drop, indicating that the areas had a high frictional strength and suppressed the coseismic slip of the 2011 Tohoku earthquake. In addition, stress drops of small earthquakes in some of the areas likely decreased after the 2011 Tohoku earthquake. This indicates that the frictional strength decreased at the areas due to the following aftershocks of the 2011 Tohoku earthquake, consistent with a high aftershock activity. This also supports that the frictional properties on a subducting plate interface can be monitored by stress drops of small earthquakes, as pointed out by some previous studies. Keywords: Frictional properties, Pacifc Plate, Stress drop, Spatio-temporal pattern, Small earthquake, East coast of the Tohoku district, 2011 Tohoku earthquake Background the east coast of the Tohoku district, Japan and found that Tectonics and characteristics of earthquakes of the east areas with a large coseismic displacement, where they coast of the Tohoku district, Japan refer to as asperities, distributed as stepping stones. -
Arc Dacite Genesis Pathways: Evidence from Mafic Enclaves and Their Hosts in Aegean Lavas ⁎ G.F
Lithos 95 (2007) 346–362 www.elsevier.com/locate/lithos Arc dacite genesis pathways: Evidence from mafic enclaves and their hosts in Aegean lavas ⁎ G.F. Zellmer a,b, , S.P. Turner c a Institute of Earth Sciences, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan, ROC b Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, New York 10964, USA c GEMOC, Department of Earth and Planetary Sciences, Macquarie University, Sydney, NSW 2109, Australia Received 4 January 2006; accepted 17 August 2006 Available online 25 September 2006 Abstract Mafic enclaves are commonly found in intermediate arc magmas, and their occurrence has been linked to eruption triggering by pre-eruptive magma mixing processes. New major, trace, Sr–Nd and U–Th isotope data of rocks from Nisyros in the Aegean volcanic arc are presented here. Pre-caldera samples display major and trace element trends that are consistent with fractionation of magnetite and apatite within intermediate compositions, and zircon within felsic compositions, and preclude extensive hybrid- ization between mafic and felsic magmas. In contrast, post-caldera dacites form a mixing trend towards their mafic enclaves. In terms of U-series isotopes, most samples show small 238U excesses of up to ∼10%. Mafic enclaves have significantly higher U/Th ratios than their dacitic host lavas, precluding simple models that relate the mafic and felsic magmas by fractionation or aging alone. A more complicated petrogenetic scenario is required. The post-caldera dacites are interpreted to represent material remobilized from a young igneous protolith following influx of fresh mafic magma, consistent with the U–Th data and with Sr–Nd isotope constraints that point to very limited (b10%) assimilation of old crust at Nisyros. -
The Evolution of the Island Arc of Japan and the Formation of Granites in the Circum-Pacific Belt
JOURNALOF GEOMAGNETISMAND GEOELECTRICITY VOL. 23, No. 3, 4, 1971 The Evolution of the Island Arc of Japan and the Formation of Granites in the Circum-Pacific Belt Naoto KAWAI, Tadashi NAKAJIMA and Kimio HIROOKa+ Department of Material Physics, Faculty of Engineering Science, Osaka University, Osaka, Japan (Received April 27, 1971) Abstract From a palaeomagnetic study and radiometric investigation of Cretaceous intrusive rocks it was recently suggested that the Palaeozoic basin formed in the northeastern Japan was severely deformed at the end of Mesozoic era. This resulted in a narrowing and shortening of the entire length of the Japanese islands. The northeastern block moved southwestward by approximately 200km and southwestern northeastward by 150km, whereas the middle block remained relative- ly unmoved but was compressed between the two blocks. As the compressional forces increased, first the Palaeozoic sediments of the central block were uplifted, and subsequently the "median line" was formed. Along the latter line, the northern half of the southern block moved eastward relative to the southern half. A strong uniaxial stress superimposed upon a hydrostatic one oc- curred associated with the relative movement. The sediments as the results recrystallized to form the three major metamorphic belts. During and after these movements, the compressed zone in the middle of the island was push- ed to the east to form a great warp in the island. Such a simple model of a bend accompanied by a tension crack as predicted by Kawai, Ito and Kume several years ago was reconsidered. The contraction of the basin was finally related to the eastward drift of Asian continent upon the Creta- ceous Pacific sea floor. -
Western Bering Sea Pacific Cod and Pacific Halibut Longline
MSC Sustainable Fisheries Certification Western Bering Sea Pacific cod and Pacific halibut longline Public Consultation Draft Report – August 2019 Longline Fishery Association Assessment Team: Dmitry Lajus, Daria Safronova, Aleksei Orlov, Rob Blyth-Skyrme Document: MSC Full Assessment Reporting Template V2.0 page 1 Date of issue: 8 October 2014 © Marine Stewardship Council, 2014 Contents Table of Tables ..................................................................................................................... 5 Table of Figures .................................................................................................................... 7 Glossary.............................................................................................................................. 10 1 Executive Summary ..................................................................................................... 12 2 Authorship and Peer Reviewers ................................................................................... 14 2.1 Use of the Risk-Based Framework (RBF): ............................................................ 15 2.2 Peer Reviewers .................................................................................................... 15 3 Description of the Fishery ............................................................................................ 16 3.1 Unit(s) of Assessment (UoA) and Scope of Certification Sought ........................... 16 3.1.1 UoA and Proposed Unit of Certification (UoC) .............................................. -
Exploring Submarine Arc Volcanoes Steven Carey University of Rhode Island, [email protected]
University of Rhode Island DigitalCommons@URI Graduate School of Oceanography Faculty Graduate School of Oceanography Publications 2007 Exploring Submarine Arc Volcanoes Steven Carey University of Rhode Island, [email protected] Haraldur Sigurdsson University of Rhode Island Follow this and additional works at: https://digitalcommons.uri.edu/gsofacpubs Terms of Use All rights reserved under copyright. Citation/Publisher Attribution Carey, S., and H. Sigurdsson. 2007. Exploring submarine arc volcanoes. Oceanography 20(4):80–89, https://doi.org/10.5670/ oceanog.2007.08. Available at: https://doi.org/10.5670/oceanog.2007.08 This Article is brought to you for free and open access by the Graduate School of Oceanography at DigitalCommons@URI. It has been accepted for inclusion in Graduate School of Oceanography Faculty Publications by an authorized administrator of DigitalCommons@URI. For more information, please contact [email protected]. This article has This been published in or collective redistirbution of any portion of this article by photocopy machine, reposting, or other means is permitted only with the approval of The approval portionthe ofwith any permitted articleonly photocopy by is of machine, reposting, this means or collective or other redistirbution SP ec I A L Iss U E On Ocean E X P L O R ATIO N Oceanography , Volume 20, Number 4, a quarterly journal of The 20, Number 4, a quarterly , Volume O ceanography Society. Copyright 2007 by The 2007 by Copyright Society. ceanography Exploring O ceanography Society. All rights All reserved. Society. ceanography O Submarine Arc Volcanoes or Th e [email protected] Send Society. ceanography to: correspondence all B Y S T even C A R E Y an D H A R A LDUR SIGURD ss O N Three quarters of Earth’s volcanic activ- although a significant part of arc volca- tion of tsunamis (Latter, 1981). -
Viscous Volcanos 2016 Grades 6-8 (Earth Science)
2016 Deepwater Exploration of the Marianas Viscous Volcanoes Focus Serpentine mud volcanoes Grade Level 6-8 (Earth Science) Focus Question What are serpentine mud volcanoes and how are they different from magma volcanoes? Learning Objectives • Students will describe mud volcanoes, contrast them with magma volcanoes, and explain how these structures, the Mariana Islands, and the Mariana Trench are related to the motion of tectonic plates. Materials For each serpentine mud volcano model: q Plastic tubing, approximately 1/4” outer diameter, 1/8” inside diameter q 2-liter plastic soda bottle q Fast-setting epoxy glue q Air-cure modeling clay, approximately 500 ml q Fine sand, table salt, or finely ground coffee q Drill and drill bit to match outside diameter of plastic tubing For each sediment-derived mud volcano model: q 2-liter plastic soda bottle q Cardboard or acrylic disk, diameter slightly smaller than soda bottle diameter q Fine sand or clay q Drill and drill bits, 3/8” and 1/2” For each magma volcano model: q Modeling materials, depending upon techniques chosen (see Learning Procedure, Step 1d and Step 4. Image captions/credits on Page 2. Audio-Visual Materials q (Optional) Interactive whiteboard Teaching Time If you need assistance with this document, please contact NOAA 1 Two or three 45-minute class periods Fisheries at (808) 725-5000. www.oceanexplorer.noaa.gov Viscous Volcanos 2016 Grades 6-8 (Earth Science) Seating Arrangement Groups of two to four students Maximum Number of Students 30 Key Words Mariana Arc Serpentine Mud volcano Mariana Trench Magma volcano Tectonic plate Images from Page 1 top to bottom: This Google Earth map shows the operating area of the 2016 Deepwater Background Information Exploration of the Marianas Expedition. -
Overview of the Precursors and Dynamics of the 2012-13 Basaltic
Journal of Volcanology and Geothermal Research 299 (2015) 19–34 Contents lists available at ScienceDirect Journal of Volcanology and Geothermal Research journal homepage: www.elsevier.com/locate/jvolgeores Overview of the precursors and dynamics of the 2012–13 basaltic fissure eruption of Tolbachik Volcano, Kamchatka, Russia Alexander Belousov a,⁎,MarinaBelousovaa,BenjaminEdwardsb, Anna Volynets a, Dmitry Melnikov a a Institute of Volcanology and Seismology, Petropavlovsk-Kamchatsky, Russia b Dickinson College, PA, USA article info abstract Article history: We present a broad overview of the 2012–13 flank fissure eruption of Plosky Tolbachik Volcano in the central Received 14 January 2015 Kamchatka Peninsula. The eruption lasted more than nine months and produced approximately 0.55 km3 DRE Accepted 22 April 2015 (volume recalculated to a density of 2.8 g/cm3) of basaltic trachyandesite magma. The 2012–13 eruption of Available online 1 May 2015 Tolbachik is one of the most voluminous historical eruptions of mafic magma at subduction related volcanoes glob- ally, and it is the second largest at Kamchatka. The eruption was preceded by five months of elevated seismicity and Keywords: fl Kamchatka ground in ation, both of which peaked a day before the eruption commenced on 27 November 2012. The batch of – – 2012–13 Tolbachik eruption high-Al magma ascended from depths of 5 10 km; its apical part contained 54 55 wt.% SiO2,andthemainbody – fi Basaltic volcanism 52 53 wt.% SiO2. The eruption started by the opening of a 6 km-long radial ssure on the southwestern slope of Eruption dynamics the volcano that fed multi-vent phreatomagmatic and magmatic explosive activity, as well as intensive effusion Eruption monitoring of lava with an initial discharge of N440 m3/s. -
Ecoregion-Based Conservation in the Bering Sea
Ecoregion-Based Conservation in the Bering Sea Identifying Important Areas for Biodiversity Conservation Contents Page# PART ONE: INTRODUCTION 3 1.2 Why conduct…. 3 1.3 Description… 4 1.4 Biolog Signif… 4 1.5 Changes…. 4 1.6 Conservation opps.. 5 PART TWO: WORKSHOP REPORT 8 2.1 Methodology: Assessing Biodiversity 8 2.2 Experts Workshop 10 2.3 Selecting Conservation Priorities:The Approach 10 Subregions: Bering Strait Bering Sea Shelf Kamchatka Shelf and Coast Aleutian Islands Aleutian Basin Taxa Birds Mammals Fish Invertebrates 2.4 Threat Assessment Summary 13 2.5 Additional Issues of Concern 16 PART THREE: BEYOND MAPS, TOWARD CONSERVATION 19 3.1 Lessons from Girdwood Workshop 19 3.2 Next Steps 21 Edited by: David Banks, Margaret 3.3 The Nature Conservancy and the Bering Sea 22 Williams John Pearce, Alan Springer, 3.4 WWF and the Bering Sea 22 Randy Hagenstein, and David Olson APPENDIX A: MAPS 2-9 A1 Publication design by Eric Cline 2 Subregions of the Bering Sea A2 3 Priority Bird Areas A3 Maps and GIS Data by: Emma BIRD TABLE A4 Underwood, Jennifer D’Amico, 4 Priority Mammal Areas A5 Carrie Wolfe, and Julie Maier MAMMAL TABLE A6 5 Priority Fish Areas A7 A collaborative effort by the FISH TABLE A8 World Wildlife Fund, 6 Priority Invertebrate Areas A9 The Nature Conservancy of Alaska, INVERT TABLE A10 and Participants in the 7 Overlapping Priority Areas for all Taxa A11 Girdwood Bering Sea Experts 8 Priority Areas for Bering Sea Biodiversity A12 Workshop March 20-23, 1999 9 Existing Protected Areas of the Bering Sea A13 Cover photo of walruses by Kevin APPENDIX B: PRIORITY AREA DESCRIPTIONS B1 Schafer, provided courtesy of the photographer APPENDIX C: LITERATURE CITED IN APP. -
Origin of Marginal Basins of the NW Pacific and Their Plate Tectonic
Earth-Science Reviews 130 (2014) 154–196 Contents lists available at ScienceDirect Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev Origin of marginal basins of the NW Pacificandtheirplate tectonic reconstructions Junyuan Xu a,⁎, Zvi Ben-Avraham b,TomKeltyc, Ho-Shing Yu d a Department of Petroleum Geology, China University of Geosciences, Wuhan, 430074, China. b Department of Geophysics and Planetary Sciences, Tel Aviv University, Ramat Aviv 69978, Israel c Department of Geological Sciences, California State University, Long Beach, CA 90840, USA d Institute of Oceanography, National Taiwan University, Taipei, Taiwan article info abstract Article history: Geometry of basins can indicate their tectonic origin whether they are small or large. The basins of Bohai Gulf, Received 4 March 2013 South China Sea, East China Sea, Japan Sea, Andaman Sea, Okhotsk Sea and Bering Sea have typical geometry Accepted 3 October 2013 of dextral pull-apart. The Java, Makassar, Celebes and Sulu Seas basins together with grabens in Borneo also com- Available online 16 October 2013 prise a local dextral, transform-margin type basin system similar to the central and southern parts of the Shanxi Basin in geometry. The overall configuration of the Philippine Sea resembles a typical sinistral transpressional Keywords: “pop-up” structure. These marginal basins except the Philippine Sea basin generally have similar (or compatible) Marginal basins of the NW Pacific Dextral pull-apart rift history in the Cenozoic, but there do be some differences in the rifting history between major basins or their Sinistral transpressional pop-up sub-basins due to local differences in tectonic settings. Rifting kinematics of each of these marginal basins can be Uplift of Tibetan Plateau explained by dextral pull-apart or transtension. -
De Grave & Fransen. Carideorum Catalogus
De Grave & Fransen. Carideorum catalogus (Crustacea: Decapoda). Zool. Med. Leiden 85 (2011) 407 Fig. 48. Synalpheus hemphilli Coutière, 1909. Photo by Arthur Anker. Synalpheus iphinoe De Man, 1909a = Synalpheus Iphinoë De Man, 1909a: 116. [8°23'.5S 119°4'.6E, Sapeh-strait, 70 m; Madura-bay and other localities in the southern part of Molo-strait, 54-90 m; Banda-anchorage, 9-36 m; Rumah-ku- da-bay, Roma-island, 36 m] Synalpheus iocasta De Man, 1909a = Synalpheus Iocasta De Man, 1909a: 119. [Makassar and surroundings, up to 32 m; 0°58'.5N 122°42'.5E, west of Kwadang-bay-entrance, 72 m; Anchorage north of Salomakiëe (Damar) is- land, 45 m; 1°42'.5S 130°47'.5E, 32 m; 4°20'S 122°58'E, between islands of Wowoni and Buton, northern entrance of Buton-strait, 75-94 m; Banda-anchorage, 9-36 m; Anchorage off Pulu Jedan, east coast of Aru-islands (Pearl-banks), 13 m; 5°28'.2S 134°53'.9E, 57 m; 8°25'.2S 127°18'.4E, an- chorage between Nusa Besi and the N.E. point of Timor, 27-54 m; 8°39'.1 127°4'.4E, anchorage south coast of Timor, 34 m; Mid-channel in Solor-strait off Kampong Menanga, 113 m; 8°30'S 119°7'.5E, 73 m] Synalpheus irie MacDonald, Hultgren & Duffy, 2009: 25; Figs 11-16; Plate 3C-D. [fore-reef (near M1 chan- nel marker), 18°28.083'N 77°23.289'W, from canals of Auletta cf. sycinularia] Synalpheus jedanensis De Man, 1909a: 117. [Anchorage off Pulu Jedan, east coast of Aru-islands (Pearl- banks), 13 m] Synalpheus kensleyi (Ríos & Duffy, 2007) = Zuzalpheus kensleyi Ríos & Duffy, 2007: 41; Figs 18-22; Plate 3. -
Weathering of Volcanic Ash in the Cryogenic Zone of Kamchatka, Eastern Russia
Clay Minerals, (2014) 49, 195–212 OPEN ACCESS Weathering of volcanic ash in the cryogenic zone of Kamchatka, eastern Russia 1, 2 E. KUZNETSOVA * AND R. MOTENKO 1 SINTEF Building and Infrastructure, Trondheim, NO-7465, Norway, and 2 Lomonosov Moscow State University, Moscow, 119991, Russia (Received 8 August 2012; revised 28 August 2013; Editor: Harry Shaw) ABSTRACT: The nature of the alteration of basaltic, andesitic and rhyolitic glass of Holocene and Pleistocene age and their physical and chemical environments have been investigated in the ash layers within the cryogenic soils associated with the volcanoes in the central depression of Kamchatka. One of the main factors controlling the alteration of the volcanic glass is their initial chemistry with those of andesitic (SiO2 =53À65 wt.%) and basaltic (SiO2 < 53 wt.%) compositions being characterized by the presence of allophane, whereas volcanic glass of rhyolitic composition (SiO2>65 wt.%) are characterized by opal. Variations in the age of eruption of individual ashes, the amount and nature of the soil water, the depth of the active annual freeze-thawing layer, the thermal conductivity of the weathering soils, do not play a controlling role in the type of weathering products of the ashes but may affect their rates of alteration. KEYWORDS: volcanic ash, allophane, opal, unfrozen water, thermal conductivity, permafrost, Kamchatka. The highly active volcanic area of Kamchatka in local and remote eruptions and from the secondary eastern Russia is part of the circum-Pacific belt of re-deposition of ash (Bazanova et al., 2005). andesitic volcanism. It is situated north of the 49th Considerable research has been carried out on the parallel of latitude and is characterized by a weathering of volcanic glass.