HR: 0800h
AN: S51A-0976    [Abstracts]
TI: Crustal Attenuation within the Turkish Plateau and Surrounding Regions
AU: * Zor, E
EM: zore@missouri.edu
AF: University of Missouri, Dept. of Geological Sciences 101 Geology Building, Columbia, MO 65211 United States
AU: Xie, J
EM: xie@ldeo.columbia.edu
AF: Columbia University, Lamont-Doherty Earth Observatory Route 9W, Pelisades, NY 10964 United States
AU: Turkelli, N
EM: turkelli@boun.edu.tr
AF: Bogazici University, Kandilli Observatory and ERI Cengelkoy, Istanbul, 81220 Turkey
AU: Sandvol, E A
EM: sandvole@missouri.edu
AF: University of Missouri, Dept. of Geological Sciences 101 Geology Building, Columbia, MO 65211 United States
AU: Mitchell, B J
EM: mitchbj@eas.slu.edu
AF: St Louis University, Earth & Atmospheric Sciences 329 Macelwane Hall 3507 Laclede Ave., St Louis, MO 63103 United States
AU: Mellors, R
EM: rmellors@geology.sdsu.edu
AF: San Diego State University, Dept. Geological Sciences MC-1020 5500 Campanile Dr. , San Diego, CA 92182 United States
AU: Gasanov, A H
S51A-0976 AF: Azerbaijan National Academy of Science, Dept. of Earth Sciences, Baku, 11182 Azerbaijan
AU: Yetirmishli, G
EM: science@azeurotel.com
AF: Azerbaijan National Academy of Science, Dept. of Earth Sciences, Baku, 11182 Azerbaijan
AB: We have imaged lateral variations in the seismic attenuation in the crust from the inversion of inter-station Lg Q measurements in Turkey and the surrounding regions. We used data collected from three temporary arrays (ETSE, WTRN, ASN) and three permanent networks (KOERI,LLNL-JSO, GSN). We used approximately 2300 waveforms from ~200 events recorded at 75 stations in the region. Our tomographic model of Lg Qo is consistent with previous more qualitative Lg attenuation models that showed inefficient or blocked Lg across the Eurasian-Arabian plate boundary. We have also found, similar to the previous models, efficient Lg propagation throughout much of the Arabian plate. A substantial variation in Lg Qo values was also found for the Arabian peninsula (~250-800). The northern Arabian platform is generally had low to normal Lg Qo values (~250 to 350). In addition, we observe high Qo (~670-800) values for the southern Arabian Plate. Additionally, we have found a dramatic decrease in Lg Qo across the Bitlis suture; the plate boundary between the Arabian and Eurasian plates. Beneath the Turkish Plateau, our high to modestly high Lg attenuation values (Qo ~100 to 200) probably originate from both scattering and intrinsic attenuation due to the tectonic complexity and the wide spread young volcanics in the region. However, we think that the lowest Qo values for the East Anatolian plateau (~70 to 100) and the portion of western Turkey around the Menderes Massif (~60 to150) are most probably caused by intrinsic attenuation. Beneath the part of the Taurus Mountains in western Anatolia, normal Lg Qo values (~200-300) have been found. These relatively higher values may be related to the nature of the crust in the Tauride mountain belt that has created a stable continental crustal waveguide for east-west ray paths. For northeastern Turkey, the Caucasus and Azerbaijan, we also found some low to normal Lg Qo values (~170-180). We have also observed a fairly consistent negative correlation between the frequency dependence of Lg Q and the magnitude of Lg Qo in the northern Middle East.
DE: 6982 Tomography and imaging (7270, 8180)
DE: 7205 Continental crust (1219)
DE: 7219 Seismic monitoring and test-ban treaty verification
DE: 8180 Tomography (6982, 7270)
SC: Seismology [S]
MN: Fall Meeting 2005