Determination of tectonic movements in the civril graben system with GNSS measurements

The Çivril Graben System (ÇGS) is one of the most important tectonic structures developed within the Western Anatolian extensional tectonic regime. With a total length of 100 km, the ÇGS has an inverted 'V' shaped geometry formed by the NW trending Baklan and NW trending Dinar grabens. The graben system consists of the Dinar, Çivril and Baklan faults. The main faults lie along the northern border of the ÇGS, while the southern border is bounded by their antithetic structures. In this research, a GNSS network covering the ÇGS and consisting of 33 sites was established to determine the velocity fields and strain rates, and 3 campaign GNSS measurements were carried out between 2022 and 2023. In addition, the GNSS data of the sites in the network in the past years were obtained from local companies. All GNSS data were processed with GAMIT/GLOBK software and the Eurasian fixed velocity field of the region was calculated. Using the velocity field, a two-dimensional strain analysis was performed. The obtained strain field shows that NW-SE directional extensions are dominant within the ÇGS. In addition, it is seen that the strain components on the Çivril fault are compatible with the right-lateral normal fault mechanism. The strain rates are at minimal levels in the Acıgöl Graben located in the south of the region.