A New Arabia-Africa-Eurasia GPS Velocity Field (1994-2014) and E Mediterranean Block Model: Implications for Continental Deformation in a Zone of Active Plate Interaction

Monday, 15 December 2014: 1:40 PM
Philippe Vernant1, Michael Floyd2, Haluk Ozener3, Semih Ergintav4, Arkadi Karakhanyan5, Fakhraddin Kadirov6, Giorgi Sokhadze7, Abdullah ArRajehi8, Hamid Nankali9, Ivan Georgiev10, Athanassios Ganas11, Demitris Paradissis12, Simon McClusky13, Francisco G Gomez14 and Robert E Reilinger2, (1)University of Montpellier II, Montpellier Cedex 05, France, (2)MIT, Cambridge, MA, United States, (3)Bogazici University, Kandilli Observatory and ERI.-Department of Geodesy, Istanbul, Turkey, (4)Bogazici University, Istanbul, Turkey, (5)Armenian Academia of Sciences, Institute of Geological Sciences, Yerevan, Armenia, (6)Azerbaijan National Academy of Sciences, Baku, Azerbaijan, (7)Ilia State University, Geodesy, Tbilisi, Georgia, (8)King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia, (9)national cartographic center, geodesy and geodynamics, Tehran, Iran, (10)Bulgarian Academy of Sciences, Sofia, Bulgaria, (11)National Observatory of Athens, Athens, Greece, (12)National Technical University of Athens (NTUA), Marousi Athens, Greece, (13)ANU, Canberra, Australia, (14)Univ Missouri, Columbia, MO, United States
We present new GPS velocities for the Arabia-Africa-Eurasia region determined with GAMIT/GLOBK (>830 velocities) spanning the period 1994-2014. Here we consider the E Mediterranean region of plate interaction. We use DEFNODE software to develop block models and estimate slip rates on major faults and strain of some blocks. The wrms of residual velocities from our new model is 1.3 mm/yr. We identify small E-W extension within the newly defined Anatolian block confined to a 100-200 km wide zone south of the North Anatolian Fault (NAF) reaching 2-3 mm/yr with rates increasing towards the west. Possible causes we consider include, un-modeled postseismic effects of the 1999 Izmit/Duzce earthquake sequence, continuing post-seismic effects of the 20th Century sequence of M>7 earthquakes, and/or toroidal sub-lithospheric flow towards the subducting Hellenic slab. The overall strain rate of the Marmara Sea block is dominantly N-S extension, and the Van block, N-S compression. Present slip rates along the NAF increase from E to W, 22-24 mm/yr along the E to E-central segment and 27-28 mm/yr along the W segment. We quantify extension in the G. of Corinth, central Greece, and G. of Evia; the W, central and E sections of the Hellenic Trench are shortening with extension in the back-arc. The W Hellenic Trench and W Peloponnese have right-lateral strike-slip and the E Hellenic Trench, left-lateral ss. N-S extension (2-4 mm/yr) in N Greece and the N Aegean Sea extends at least to 42°N. Arabia-Sinai left-lateral motion across the Dead Sea Fault is ~5 mm/yr along the S segment; significant residual velocities along the N and S segments indicate lower slip rates in the N and require fault segmentation to account for slip rate variations along strike. We identify E-W contraction of the Arabian (Persian) Gulf (~3-5 mm/yr) that extends into the E part of the Arabian Plate. We will quantify and present these and other observed deformation patterns and discuss their tectonic implications.