HR: 1340h
AN: S13B-1056    [Abstracts]
TI: Upper Mantle P and S-wave Velocity Structure Beneath Eastern Anatolian Plateau
AU: * Sandvol, E
EM: sandvole@missouri.edu
AF: Department of Geological Sciences, 101 Geology Building, Columbia, MO 65211 United States
AU: Zor, E
EM: zore@missouri.edu
AF: Department of Geological Sciences, 101 Geology Building, Columbia, MO 65211 United States
AB: The Eastern Turkey Seismic Experiment (ETSE) was designed to image the crustal and upper mantle velocity structure beneath the northernmost Arabian plate and beneath the Anatolian Plateau, constraining geodynamic models for young continent-continent collision. ETSE was composed of a 29 station broadband PASSCAL array which was deployed from October 1999 until August 2001. Tomographic mapping of the Rayleigh wave phase velocities suggests that the uppermost mantle ultra-low velocity zone is underlain by relatively normal to slightly low velocity mantle. This finding is roughly consistent with our three dimensional teleseismic P wave tomography results. The preliminary P-wave tomography, however, does not show as clear of contrast in seismic velocities across the Bitlis suture. We also observe interesting differences between the S-wave and P-wave tomography results in the center portion of the Anatolian plateau where S-wave velocities are the lowest. This might be an indication of the presence of water in the uppermost mantle in the easternmost Anatolian plateau. We have also investigated the depth extent of the azimuthal anisotropy beneath the eastern Anatolian plateau using Rayleigh wave phase velocities. It appears as if there are two anisotropic layers within the upper mantle. The top layers (periods 30 and 50 seconds) are consistent with the values obtained from Pn anisotropy and shear wave splitting. The bottom layers (periods 100 - 150 seconds) are not consistent with fast directions obtained from shear wave splitting and Pn azimuthal anisotropy. The two layers are separated by a region that has relatively little anisotropy.
DE: 7255 Surface waves and free oscillations
DE: 7203 Body wave propagation
DE: 7205 Continental crust (1242)
DE: 7218 Lithosphere and upper mantle
SC: Seismology [S]
MN: 2004 AGU Fall Meeting