ENVISAT Summer School - ESA/ESRIN - Frascati - Rome - Italy, 4-14 August 2008

ContributionContribution ofof -GPS-GPS andand GIS-assistedGIS-assisted SpacSpaceborneeborne RemoteRemote SensingSensing inin SatelliteSatellite GeodesyGeodesy andand inin thethe Morpho-SeismotectonicMorpho-Seismotectonic research research aroundaround thethe citycity ofof ThessalonikiThessaloniki (N.(N. Greece)Greece)

AntoniosAntonios MOURATIDIS MOURATIDIS (a, (a, b) b), ,Pierre Pierre BRIOLE BRIOLE (a) (a), ,Frederique Frederique ROLANDONE ROLANDONE (c) (c) (a)(a) Laboratoire Laboratoire de de Géologie, Géologie, Ecole Ecole Normale Normale Supérieure Supérieure (ENS), (ENS), Paris, Paris, France France (b)(b) Aristotle Aristotle University University of of Thessaloniki Thessaloniki (AUTH), (AUTH), Thessaloniki, Thessaloniki, Greece Greece (c)(c) Laboratoire Laboratoire de de Tectonique, Tectonique, Université Université Pierre Pierre et et Marie Marie Curie Curie (Paris (Paris VI), VI), Paris, Paris, France France

1.1. STUDYSTUDY AREASAREAS && DATADATA

General Information Location: Thessaloniki, Central Macedonia, Northern Greece Max. elevation: 1201 m (Hortiatis/Kissos) Kalohori area: A Min. elevation: a few m below MSL (near Kalohori) 9 Part of the Thessaloniki Plain Land cover: agricultural areas (51%), bushes (21%), forests (12%) pasture (7%)[3] 9 2,500 year old delta [1], [7] 9 4 rivers flowing through the broader area [2], [7], [8] 9 Known (few cm/yr) Broader Mygdonian basin: B 9 Tectonic origin (graben) SPOT-5: 9 Formed by successive normal faulting (extension) Base map GPS B 9 Most active region in Northern Greece Stereo DEM A TerraSAR-X: LANDSAT-5 9 Several active faults Validation /TM: sample Multispectral 9 Population concentration & high seismicity info 9 Ms = 6.5, 20th June 1978 [5] REMOTE [5] SENSING 9 N-S extension: approx. 5 mm/yr (1979-1994) ERS-1/-2 DATA LANDSAT-7: [6] /SAR /ETM+: 9 slip rate: max. 0.3-0.6 mm/yr InSAR+ Multispectral info

SRTM ENVISAT DEM: /ASAR: InSAR InSAR+ GPS DEMs GISGIS collection, synthesis, correlation, analysis and visualization 2.2. KINEMATICKINEMATIC GPSGPS MEASUREMENTSMEASUREMENTS of all data and results 3.3. SARSAR INTERFEROMETRYINTERFEROMETRY

ENVISAT/ASAR - track 279 (D) GPS campaign details InSAR details

800 28/3/2004; 764 Sampling rate: 1 Hz No. of Envisat/ASAR data: 18 * 4/9/2005; 503 16/7/2006; 636 26/2/2006; 494 300 24/10/2004; 191 13/3/2005; 192 o 13/11/2005; 112 Elevation mask: 5 Track/Type: 279/Descending 17/4/2005; 0 -200 22/5/2005; -234 22/4/2007; -309 5/8/2007; -321 22/6/2003; -391 11/6/2006; -440

Baseline (m) (m) Baseline 11/7/2004; -413 Possible In/grams: 153 11/2/2007; -483 Mean vehicle speed: 35 km/h 9/3/2003; -608 -700 29/10/2006; -700 20/10/2002; -837 6/2/2005; -665 Total distance: 720 km Computed In/grams: 117 -1200 9/11/2003; -1190 2002 2003 2004 2005 2006 2007 2008 Duration: 22 h in 4 days Processing: ROI_PAC Dat e

Collected data: > 60,000 points * 74 ERS Interferograms from a large archive (>100 data) of the Mygdonian graben and Kalohori areas have been also computed and are currently under evaluation. GPS data & Google ASAR track 279 D, wrapped differential interferogram, 6 Feb 2005- 29 Oct 2006

Coherence map based on 117 ENVISAT/ASAR interferograms

4.4. DISCUSSIONDISCUSSION && RESULTSRESULTS Estimated subsidence contours from leveling and GPS data for the last 50+ years [7] •C-band•C-band InSARInSAR indicatesindicates subsidsubsidenceence inin thethe orderorder ofof 33 cm/ycm/yrr (approx.(approx. 1 1 fringe/yr)fringe/yr) inin thethe areaarea ofof Kalohori.Kalohori. ThisThis raterate ofof subsidencesubsidence && ititss spatialspatial distributiondistribution araree inin accordanceaccordance withwith previousprevious studies.studies.

•Loss•Loss ofof coherencecoherence inin non-urbannon-urban areasareas preventsprevents cleanclean andand fullfull formingforming ofof fringes,fringes, butbut largelarge amountamount ofof interferogramsinterferograms andand a-a-prioripriori informationinformation supportsupport thethe results.results.

•Possibility•Possibility forfor thethe future,future, toto monitormonitor thethe subsidencesubsidence phenomenonphenomenonwithwith L-bandL-band InSARInSAR (coherence(coherence preserved,preserved, althoughalthough lessless sensiblesensible,, 11 fringefringe == 1212 cm),cm), as as soonsoon asas moremore datadata isis availableavailable (e.g.(e.g. ALOS/PALSAR):ALOS/PALSAR): 3cm/yr3cm/yr =>=> inin 44 yrsyrs == 11 fringefringe withwith L-band.L-band.

•Mygdonian•Mygdonian basin: basin: lowlow coherencecoherence ++ slowslow dedeformationformation (further(further ininvestigationvestigation needed)needed) ReferencesReferences •Kinematic•Kinematic GPSGPS data,data, aa tooltool for:for: (a)(a) vavalidatinglidating DEMDEM accuracyaccuracy andand reliability,reliability, (b)(b) [1][1]Astaras,Astaras, T. T. A., A., Sotiriadis, Sotiriadis, L. L. (1988). (1988). Th Thee Evolution Evolution of of the the Thessaloniki-Giannitsa Thessaloniki-Giannitsa Pla Plainin in in Northern Northern Greece Greece During During the the Last Last 2500 2500 collecting GCPs & georeferencing RS data, (c), independent, long-term monitoring of yearsyears - - From From the the Alexander Alexander the the Great Great Era Era Until Until Today. Today. Lake, Lake, Mire Mire and and River River Environments Environments During During the the Last Last 15 15 000 000 years. years. collecting GCPs & georeferencing RS data, (c), independent, long-term monitoring of Balkema, Rotterdam, 105-114. fast vertical movements (e.g. subsidence). Balkema, Rotterdam, 105-114. fast vertical movements (e.g. subsidence). [2][2]Andronopoulos,Andronopoulos, B., B., Rozos, Rozos, D. D. & & Hadzinakos, Hadzinakos, I. I. (1991). (1991). Subsiden Subsidencece Phenomena Phenomena in in the the Industrial Industrial Area Area of of Thessaloniki, Thessaloniki, Greece, Greece, th LandLand Subsidence Subsidence (Proc. (Proc. 4 4thInternationalInternational Symposium Symposium on on Land Land Subsidence, Subsidence, May May 1991), 1991), IAHS IAHS Publ., Publ., 200, 200, 59-69. 59-69. [3][3]GreekGreek Ministry Ministry of of Agriculture Agriculture (1994). (1994). Forestry Forestry map map (1:200,000) (1:200,000) of of the the Prefecture Prefecture of of Thessaloniki, Thessaloniki, Forestry Forestry Service Service of of Greece Greece AcknowledgementsAcknowledgements [4][4]Martinod,Martinod, J., J., Hatzfeld, Hatzfeld, D., D., Savvaidis, Savvaidis, P. P. & & Katsambalos, Katsambalos, K. K. (1997). (1997). Rapid Rapid N-S N-S extension extension in in the the Mygdonian Mygdonian graben graben (Northern (Northern Greece)Greece) deduced deduced from from repeated repeated geodetic geodetic survey surveys,s, Geophysical Geophysical Research Research Letters, Letters, 24, 24, 24, 24, 3293-3296. 3293-3296. [5] Papazachos, B. C., Papazachou, C., (1997). The Earthquakes of Greece, Ziti Publications, Thessaloniki. SpecialSpecial thanksthanks toto ESAESA, , ENSENS, , AUTHAUTH, , IKYIKY, , ParisParis VIVI, , InfoTERRAInfoTERRA GmbH GmbH&& OASISOASIS projectprojectforfor makingmaking [5] Papazachos, B. C., Papazachou, C., (1997). The Earthquakes of Greece, Ziti Publications, Thessaloniki. [6] Pavlides, S. (2003). of Earthquakes: Introduction to Neotectonics, Morphotectonics & Palaeoseismology, University thisthis work work possible possible by by providing providing data, data, knowledge, knowledge, facilities, facilities, human human resources resources & & funding. funding. [6] Pavlides, S. (2003). Geology of Earthquakes: Introduction to Neotectonics, Morphotectonics & Palaeoseismology, University StudioStudio Press, Press, Thessaloniki Thessaloniki (In (In Greek). Greek). Maya ILIEVA, Penelope LOPEZ, Rana CHARARA & Moez BACCOUCHE are gratefully Maya ILIEVA, Penelope LOPEZ, Rana CHARARA & Moez BACCOUCHE are gratefully [7][7] Psimoulis, Psimoulis, P., P., Ghilardi, Ghilardi, M., M., Fouache, Fouache, E., E., St Stiros,iros, S. S. (2007). (2007). Subsidence Subsidence and and evolution evolution of of the the Thessaloniki Thessaloniki plain, plain, Greece, Greece, based based on historical leveling and GPS data. Engineering Geology, 90, 55-70. acknowledgedacknowledged forfor thethe fruitfulfruitful collaboration,collaboration, thethe enendlessdless discussionsdiscussions andand allall thethe funfun inin FranceFrance andand on historical leveling and GPS data. Engineering Geology, 90, 55-70. [8] Stiros, S. C. (2001). Subsidence of the Thessaloniki (northern Greece) coastal plain, 1960-1999. Engineering Geology, 61, elsewhere…elsewhere… [8] Stiros, S. C. (2001). Subsidence of the Thessaloniki (northern Greece) coastal plain, 1960-1999. Engineering Geology, 61, 243-256243-256. .