Initial Results from the Central Anatolian Seismic Experiment: Local Seismicity and Shear Wave Splitting

Abstract

In order to create high-resolution images of the crust and upper mantle in central Anatolia, we deployed a 2-year 71 station broadband embedded the Kandilli Observatory and Earthquake Research Institute (KOERI) of Bogazici University national seismic network. This study focuses on crust and upper mantle studies such as earthquake locations (especially micro-seismic activity) and shear wave splitting (SKS) analysis. Distribution of earthquake locations supports the presence of seismic activity partly localized along major tectonic structures. The CAFZ, generally considered to be less seismically active, shows a significant amount of seismic activity that is consistent with internal plate deformation. Additional seismicity is observed near volcanically active regions of central Anatolia. We found that velocities for the crust and uppermost mantle are; P waves 6.01 km/s, and 8.21 km/s, and for S waves 3.89 km/s, and 4.64 km/s, respectively. The shear-wave splitting analysis has been carried out on teleseismic data acquired by CD-CAT stations mainly from May-2013 to 2014. The averaged fast polarization directions in the EAFZ are fairly uniform and show NE-SW orientations, but they are well aligned with the EAFZ. Rapid spatial variations in splitting parameters are observed at the stations located in the Adana region.