Modeling of tectonic movements with gnss meausurements: Gülbahce fault case

In this study, the kinematic structure of the Gülbahçe fault is examined, which is one of the most active faults and have the potential to generate earthquakes in Izmir and its surroundings. A GNSS network with 17-site was established in the region, which includes some parts of Urla, Çeşme and Karaburun districts of Izmir. GNSS measurements on the sites of the network were carried out from various institutions and organizations in the past years. One campaign measurement was carried out on 6 sites in 2019. Velocities of the sites and strain fields of the region were calculated. When the strain fields are examined, it is seen that the NNE-SSW extension and NNW-SSE compression are dominant on the fault and in the Gulf of Gülbahçe. Strain fields show that the fault type of Gülbahçe fault is left strike-slip. The same situation could be seen in the relative velocities. Using strain parameters, geodetic earthquake recurrance periods for Mw≥6 and Mw≥7 were calculated. According to these periods, the region has recurrence periods of 65-120 years for Mw≥ 6 and 790-4330 years for Mw ≥7.