P-Alıcı Fonksiyonları ve Rayleigh Dalgası Grup Hızları’nın Birleşik Ters Çözümü’nden Doğu Anadolu Fay Zonu’nun Kabuk ve Üst Manto Hız Yapısı

Abstract

The Eastern Anatolian Fault Zone (EAFZ) is an active plate boundary where intense seismicity has occurred from past to present. This activity is related to the geodynamic structure of the region. Because of the Arabian plate northward motion and the Eurasian plate southward motion, the Anatolian plate has attempted to escape westward with anticlockwise rotation, caused the development of important tectonic structures. Concerning these active plate motions, the S-wave velocity structure of EAFZ intersecting the North Anatolian Fault Zone (NAFZ) in the northeast and the Dead Sea Fault Zone (DSFZ) in the southwest is important in interpreting the tectonics of region. The present study is conducted on the joint inversion of P-wave receiver functions and Rayleigh wave group velocities techniques using the data collected from eight broadband stations along the EAFZ. The P-receiver functions are analyzed using approximately eighty teleseismic events for each station, recorded by the three-component broadband seismometers. On the other hand, for the Rayleigh wave group velocity dispersion curves calculations twenty-one regional earthquakes are used, which have focal depth less than 50 km and bigger than moment magnitude Mw=5.0. The analyses obtained from these two techniques is jointly inverted to determine the 1-D S-wave velocity structure of crust and uppermost mantle for each station. The results of inversion indicate that the S-wave velocity models show that the low-velocity layers are identified within the approximately 4-12 km in the upper crust. Besides, the Conrad discontinuity is determined as the depth of ~22 km along with the seismic stations. Furthermore, the crust-mantle boundary is ~44 km depth along with the EAFZ. Consequently, this study yields the crustal and uppermost mantle S-wave velocity structure compatible with the regional tectonics of the studied region.