Monitoring of surface deformations in Bolvadin by different geodetic methods

The aim of this study is to examine the aseismic surface deformations that were formed and continue to occur in the settlement area without destructive earthquakes in the continuation of the Bovadin Fault, which is included in the ASFS (Akşehir Simav Fault System). For this, GNSS (Global Navigation Satellite System), Leveling and SAR (Synthetic Aperture Radar) methods were used to determine the deformations in and around Bolvadin district. Vertical deformations were determined comparatively by using three different methods. In this context, 3 continuous GNSS stations, one in 2017 and two in 2020, were established in the region where surface deformations are active in Bolvadin. In addition, a leveling network consisting of profiles perpendicular to the fault was established and 5 campaign precision leveling measurements were carried out in this network between 2016-2020. Finally, vertical deformations in the region were also obtained by using Sentinel-1 satellite images between the years 2016-2020. According to the results obtained from the GNSS data, the maximum deformation rate in the region was calculated as -94 mm/yr (BLV1 station). Additionally, the precision leveling results shows the maximum deformation rate at the leveling points close to BLV1 GNSS station is -78 mm/yr. Consistent with the GNSS and Leveling results, the deformation rate was calculated as -82 mm/yr according to the results obtained from the InSAR data. All results obtained from the three methods are compaitable. Accordingly, when all the results are evaluated, it is seen that the annual vertical deformation rates around the BLV1 GNSS station are -80 to -90 mm.