Application of receiver function technique to western Turkey

In this study I tried to determine the shear wave velocity structure in the crust and uppermost upper mantle using receiver function technique. For this purpose I selected teleseismic earthquakes in the epicentral distances between 30 and 90 degrees, magnitudes of which are greater than 6.3. I collected waveform data recorded at Turkey's broadband seismic stations between 2006 and 2008. I used radial receiver functions which were calculated using extended time multitaper method to determine the crustal and uppermost upper mantle structure. My study consists of three steps: receiver function (RF) calculation, RF image and RF inversion. Because of the data availability, I studied data of 33 stations in western Turkey which belong to the General Directorate of Disaster Affairs Earthquake Research Department and Bogazici University Kandilli Observatory. First, I calculated radial receiver functions for each station. In the next step, I made two RF images using the RFs from stations along two lines: the one is running from the northeast of Bozcaada to Konya city and the other is running from the north of Izmir to the northeast comer of Rhodes island. In the third step, I applied genetic algorithm inversion method to determine the shear wave velocity structure beneath six seismic stations. The results show that the Moho depth changes from region to region; we observed that the Moho depth is around 35 km and 25 km beneath the former and latter profiles, respectively. The results of receiver function inversion are consistent with these RF images. Shear wave velocities were estimated to be in the range between 3.5 and 3.9 km/s for the lower crust and between 4.0 and 4.6 km/s for the uppermost upper mantle, respectively.