Recent tectonic features of Western Anatolia based on half-space modeling of GNSS Data

Abstract

A new block model including a 111-site GNSS network was computed to determine deformation pattern in Western Anatolia. These GNSS sites serving the block model were observed for at least 16 h within two consecutive days in 3 different years ranging from 2005-2010. The GNSS dataset obtained from this network were processed with GAMIT / GLOBK software and a high-precision Eurasia-fixed velocity field was produced for the Western Anatolia region. The results show that the region moves in the southwest direction with rates of 18–28 mm/yr with respect to Eurasian plate . To study the crustal stretching of the study area, we computed a novel model consisting of 6 blocks and 14 fault segments. Unlike the previously published block models, our preferred model consists of relatively smaller blocks and much more GNSS sites. Most of the block boundaries align almost in E -W direction except for one lying along NE-SW accommodated with İzmir-Balıkesir Transfer Zone that has the highest lateral movement throughout the region. Achieved results highlight the importance of the structural elements in an active crustal stretching setting, with transfer faults approximately parallel to the main extension direction. • A new block model consisting of 6 blocks was suggested for the Western Anatolia. • The eastern boundary of İBTZ has the highest lateral movement throughout the region. • The western border of İBTZ has been torn or lost its activity. • The part of the Güzelhisar fault on the sea floor is considered to be active. • It can be an active fault extending through NE-SW between GFZ and HBFZ.