The velocity of aseismic surface deformations between 2016‑2020 detected by precise leveling surveys of the Akşehir Simav Fault System in the Bolvadin district, western Anatolia

Abstract

In this research, the aim was to examine the aseismic surface deformations that occurred in the Bolvadin district center with a precise leveling technique. For this purpose, a geodetic leveling network consisting of eight profiles and 81 benchmarks was installed in the region, and five campaigns of precise leveling measurements were performed between 2016-2020. As a result of the evaluations of the leveling measurements, deformations over time were calculated at each benchmark. In consequence of the evaluation of the five campaign measurements, the deformation amount increased continuously from 2016 to 2020. When the adjusted height differences between 2019‑2020 were examined, it was observed that the deformation amount of the previous years doubled. Additionally, deformation rates between –20 and –90 mm/year were estimated using the Kalman filtering methods. According to the current data obtained, the total vertical displacement amount has reached approximately 1 m and the deformation continues today.