GPS‐derived strain rate field within the boundary zones of the Eurasian, African, and Arabian Plates

We use the GPS velocity field (1988–1998) for eastern Mediterranean and Asia Minor to determine the crustal deformation strain rate field in an area bounded by 35°N and 43°N, and 20°E and 48°E. We calculate the normal and shear strain rate components associated with the major faults and compare these qualitatively with seismological data. Uncertainties in the calculation of the strain rates reach 50 nstrain yr−1 in sparsely observed parts of Anatolia, whereas we estimate errors <20 nstrain yr−1 in the Aegean and Marmara regions. The largest compressional strain rate components in the eastern part of the study area occur along the Greater Caucasus mountain front reaching 70 nstrain yr−1. (1 nstrain yr−1 = 0.0317 × 10−15 s−1). The North Anatolian Fault Zone is the clearest feature in the shear strain rate field. It is expressed as a pronounced dextral strike-slip fault zone, reaching rates of up to 170 nstrain yr−1. This holds true also for the Izmit area, where the August 17, 1999, earthquake occurred. Central Anatolia is almost strain-free, whereas extension prevails in western Anatolia. The principal axes of extension vary around the N-S direction with strain rates of up to 85 nstrain yr−1. These extensional areas coincide with graben features and normal faulting earthquakes. The central and southwestern Aegean Sea is strain-free with values far below 40 nstrain yr−1. The seismic cluster around the Dodekanissa islands, southeastern Aegean Sea, coincides with NW-SE oriented extension, attaining strain rates of up to 90 nstrain yr−1. This area of extension also exhibits recent active volcanism. The entire Hellenic arc shows compressional strain rates perpendicular to the arc. The Pliny-Strabo troughs along the eastern segment of the arc show left-lateral shear strain rates reaching 80 nstrain yr−1. Significant extension is found in central Greece, with a NNE-SSW oriented maximum of 120 nstrain yr−1 centered around the Gulf of Corinthos. The Kephalonia Fault Zone in NW Greece is a distinct dextral fault zone, separating Apulia from the rapidly moving Aegean microplate. Right-lateral shear strain rates reach 150 nstrain yr−1.

[1]  Demitris Paradissis,et al.  Global Positioning System constraints on plate kinematics and dynamics in the eastern Mediterranean and Caucasus , 2000 .

[2]  G. Veis,et al.  New constraints on the rapid crustal motion of the Aegean region: recent results inferred from GPS measurements (1993–1998) across the West Hellenic Arc, Greece , 1999 .

[3]  Peter J. Clarke,et al.  Source parameters of the 1 October 1995 Dinar (Turkey) earthquake from SAR interferometry and seismic bodywave modelling , 1999 .

[4]  R. King,et al.  The GPS strain rate field in the Aegean Sea and western Anatolia , 1999 .

[5]  Bertrand Meyer,et al.  Westward propagation of the North Anatolian fault into the northern Aegean: Timing and kinematics , 1999 .

[6]  S. Ward.  On the consistency of earthquake moment release and space geodetic strain rates: Europe , 1998 .

[7]  Walter H. F. Smith,et al.  New, improved version of generic mapping tools released , 1998 .

[8]  D. Giardini,et al.  A geodynamic framework for eastern Mediterranean kinematics , 1998 .

[9]  J. Chorowicz,et al.  Recent volcanism, tectonics and plate kinematics near the junction of the African, Arabian and Anatolian plates in the eastern Mediterranean , 1998 .

[10]  Horasan Gündüz,et al.  S‐wave attenuation in the Marmara Region, northwestern Turkey , 1998 .

[11]  L. Rybach,et al.  Geothermal reconnaissance of the Marmara Sea region (NW Turkey): surface heat flow density in an area of active continental extension , 1998 .

[12]  James Jackson,et al.  Faulting associated with historical and recent earthquakes in the Eastern Mediterranean region , 1998 .

[13]  G. Baer,et al.  Block rotations and continental extension in the central Aegean Sea: palaeomagnetic and structural evidence from Tinos and Mykonos (Cyclades, Greece) , 1998 .

[14]  A. Koçyi̇ği̇t,et al.  A new intracontinental transcurrent structure: the Central Anatolian Fault Zone, Turkey , 1998 .

[15]  G. King,et al.  The 1995 Kozani-Grevena earthquake (N. Greece): An introduction , 1998 .

[16]  H. Kahle,et al.  GPS and geologic estimates of the tectonic activity in the Marmara Sea region, NW Anatolia , 1997 .

[17]  O. Bellier,et al.  Recent temporal change in the stress state and modern stress field along the North Anatolian Fault Zone (Turkey) , 1997 .

[18]  M. Boccaletti,et al.  Reproducing the velocity and stress fields in the aegean Region , 1997 .

[19]  S. McClusky,et al.  Preliminary estimates of plate convergence in the Caucasus Collision Zone from global positioning system measurements , 1997 .

[20]  L. Rivera,et al.  Seismic source study of the Racha-Dzhava (Georgia) earthquake from aftershocks and broad-band teleseismic body-wave records: an example of active nappe tectonics , 1997 .

[21]  Robert W. King,et al.  Global Positioning System measurements of present‐day crustal movements in the Arabia‐Africa‐Eurasia plate collision zone , 1997 .

[22]  O. Tatar,et al.  A palaeomagnetic study of the Sivas Basin, central Turkey: Crustal deformation during lateral extrusion of the Anatolian Block , 1997 .

[23]  James H. Dieterich,et al.  Progressive failure on the North Anatolian fault since 1939 by earthquake stress triggering , 1997 .

[24]  G. King,et al.  Stress coupling between earthquakes in northwest Turkey and the north Aegean Sea , 1996 .

[25]  A. Barka,et al.  The 1 October 1995 Dinar earthquake, SW Turkey , 1996 .

[26]  P. Meijer,et al.  Temporal variation in the stress field of the Aegean Region , 1996 .

[27]  C. Straub.  Recent crustal deformation and strain accumulation in the Marmara Sea Region, N.W. Anatolia, inferred from GPS measurements , 1996 .

[28]  G. J. Mets,et al.  Crustal deformations in the Mediterranean Area computed from SLR and GPS observations , 1996 .

[29]  H. Kahle,et al.  Active crustal deformation in the Marmara Sea Region, NW Anatolia, Inferred from GPS measurements , 1995 .

[30]  G. Danuser,et al.  The strain field in northwestern Greece and the Ionian Islands: results inferred from GPS measurements , 1995 .

[31]  Spyros Pavlides,et al.  The 13 May 1995 western Macedonia, Greece (Kozani Grevena) earthquake; preliminary results , 1995 .

[32]  X. Le Pichon,et al.  Geodetic determination of the kinematics of central Greece with respect to Europe: Implications for eastern Mediterranean tectonics , 1995 .

[33]  A. Barka,et al.  Syn-rift sedimentation and structural development of the Gediz and Büyük Menderes graben, western Turkey , 1995, Journal of the Geological Society.

[34]  Anastasia Kiratzi,et al.  Active crustal deformation from the Azores triple junction to the Middle East , 1995 .

[35]  Arthur L. Lerner-Lam,et al.  Active thrust front of the Greater Caucasus: The April 29, 1991, Racha earthquake sequence and its tectonic implications , 1995 .

[36]  J. Jackson,et al.  A comparison of satellite laser ranging and seismicity data in the Aegean Region , 1994 .

[37]  David E. Smith,et al.  Horizontal crustal motion in the central and eastern Mediterranean inferred from satellite laser ranging measurements , 1994 .

[38]  L. Jolivet,et al.  Spatial transition from compression to extension in the Western Mediterranean Ridge accretionary complex , 1994 .

[39]  Rob Westaway,et al.  Present‐day kinematics of the Middle East and eastern Mediterranean , 1994 .

[40]  S. Stiros,et al.  The 1953 earthquake in Cephalonia (Western Hellenic Arc): coastal uplift and halotectonic faulting , 1994 .

[41]  L. Jolivet,et al.  3D-kinematics of extension in the Aegean region from the early Miocene to the present; insights from the ductile crust , 1994 .

[42]  James Jackson,et al.  Active Tectonics of the Aegean Region , 1994 .

[43]  A. Kiratzi.  A study on the active crustal deformation of the North and East Anatolian Fault Zones , 1993 .

[44]  H. Philip,et al.  Active tectonics in the Lesser Caucasus: Coexistence of compressive and extensional structures , 1993 .

[45]  P. Huchon,et al.  The Crust of the Western Mediterranean Ridge From Deep Seismic Data and Gravity Modelling , 1993 .

[46]  A. Zanchi,et al.  Seismotectonics of western Anatolia: Regional stress orientation from geophysical and geological data , 1993 .

[47]  Z. Ben‐Avraham,et al.  Origin and role of major strike-slip transfers during plate collision in the central Mediterranean , 1993 .

[48]  G. Tsokas,et al.  Rupture zones and active crustal deformation in southern Thessalia, Central Greece , 1993 .

[49]  C. Papazachos,et al.  Rates of active crustal deformation in the Aegean and the surrounding area , 1992 .

[50]  J. Jackson.  Partitioning of strike‐slip and convergent motion between Eurasia and Arabia in eastern Turkey and the Caucasus , 1992 .

[51]  H. Philip,et al.  Modern tectonic stress field in the Mediterranean region: evidence for variation in stress directions at different scales , 1992 .

[52]  James Jackson,et al.  Active tectonics of the north and central Aegean Sea , 1991 .

[53]  C. Langston,et al.  Moment tensor inversion of the 1983 January 17 Kefallinia event of Ionian islands (Greece) , 1991 .

[54]  J. Jackson,et al.  Seismicity and associated strain of central Greece between 1890 and 1988 , 1990 .

[55]  Richard G. Gordon,et al.  Closure of the Africa‐Eurasia‐North America Plate motion circuit and tectonics of the Gloria Fault , 1989 .

[56]  H. Philip,et al.  The Caucasus: An actual example of the initial stages of continental collision: Tectonophysics , 1989 .

[57]  Richard G. Gordon,et al.  Current plate motions , 1990 .

[58]  A. Barka,et al.  Strike‐slip fault geometry in Turkey and its influence on earthquake activity , 1988 .

[59]  H. Eyidog̃an.  Rates of crustal deformation in western Turkey as deduced from major earthquakes , 1988 .

[60]  James Jackson,et al.  The relationship between plate motions and seismic moment tensors, and the rates of active deformation in the Mediterranean and Middle East , 1988 .

[61]  W. Spakman,et al.  The Hellenic Subduction Zone: A tomographic image and its geodynamic implications , 1988 .

[62]  James Jackson,et al.  Active tectonics of the Adriatic Region , 1987 .

[63]  D. Papastamatiou,et al.  The earthquake of April 30, 1954, in Sophades (Central Greece) , 1986 .

[64]  Jean-Claude Sibuet,et al.  Geological evolution of the tethys belt from the atlantic to the pamirs since the LIAS , 1986 .

[65]  J. LaBrecque,et al.  Continuous Sea-Floor Spreading in Red Sea: An Alternative Interpretation of Magnetic Anomaly Pattern , 1985 .

[66]  M. Toksöz,et al.  Tectonic consequences of the collision of the Arabian and Eurasian plates: Finite element models , 1983 .

[67]  J. R. Cochran.  A Model for Development of Red Sea , 1983 .

[68]  P. Huchon,et al.  The tectonic development of the hellenic arc and the sea of crete: A synthesis , 1982 .

[69]  J. R. Cochran.  The Gulf of Aden: Structure and evolution of a young ocean basin and continental margin , 1981 .

[70]  X. Pichon,et al.  The hellenic arc and trench system: A key to the neotectonic evolution of the eastern mediterranean area , 1979 .

[71]  J. Dewey,et al.  Aegean and surrounding regions: Complex multiplate and continuum tectonics in a convergent zone , 1979 .

[72]  D. McKenzie.  Active tectonics of the Alpine—Himalayan belt: the Aegean Sea and surrounding regions , 1978 .

[73]  D. McKenzie.  Active Tectonics of the Mediterranean Region , 1972 .