Determination of recent tectonic deformations along the Tuz Gölü Fault Zone in Central Anatolia (Turkey) with GNSS observations

Authors: CEMİL GEZGİN, SEMİH EKERCİN, İBRAHİM TİRYAKİOĞLU, BAHADIR AKTUĞ, HEDİYE ERDOĞAN, ESRA GÜRBÜZ, OSMAN ORHAN, SÜLEYMAN SEFA BİLGİLİOĞLU, AHMET TARIK TORUN, HALİL İBRAHİM GÜNDÜZ, OSMAN OKTAR, CEZMİ TÜRKMEN, EFDAL KAYA

Abstract: The Tuz Gölü Fault Zone (TGFZ) is one of the most important active tectonic structures of Central Anatolia. The morphotectonic features of the TGFZ and the distribution of the epicenters of earthquakes over magnitude 5.0 show that this fault zone remains active today. In this study, the deformation of the TGFZ is determined with high sensitivity using geodetic measurements. To obtain accurate information about the deformation of the TGFZ, 24 GNSS sites and two continuously operating reference stations were constructed in the southern part of the TGFZ. Between 2018 and 2020, Global Navigation Satellite Systems (GNSS) measurements were made on this network. The data of the Turkish National Fundamental GPS Network (TNFGN) and the continuously operating reference stations-Turkey (CORS-TR) sites around the study area were also included in the study, and GNSS measurements were evaluated with the GAMIT/GLOBK software, and velocity fields of the region were determined. In addition, block modeling of the study area was calculated using the GeodSuit software. For the first time, slip rates provided by the geodetic network are established directly on the TGFZ segments, filling a significant deficiency in the literature, contributing to understanding the tectonics of the country and the region, and providing an important dataset for evaluating the degree of seismic activity of the fault zone. The slip rates obtained within the scope of this study are approximately 1.8 mm/yr strike-slip and 2 mm/yr dip-slip for the Acıpınar and Helvadere segments on that Aksaray city is built on. These results indicate that the active deformation in the TGFZ is greater than previously expressed compared to the slip rates calculated in previous studies.

Keywords: Tuz Gölü Fault Zone, velocity field, block modeling, global positioning system, GPS, Central Anatolia

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