Monitoring of tectonic movements of the Gediz Graben by the PSInSAR method and validation with GNSS results

In the eastern part of the Gediz Graben, especially in the Sarigol region, surface deformations that occurred without destructive earthquakes or that continue to occur are frequently observed from the 1969 Alasehir earthquake to the present. Especially in areas where aseismic and tectonic effects are thought to co-exist, such as the Gediz Graben, the general deformation character of the study area cannot be identified precisely from the surface deformations that are determined using the GNSS method as pointwise. However, the general deformation character of the study area can be identified clearly by determining the surface deformations of the study area with the PSInSAR method areally. In this study, in order to determine surface deformations that may be caused by aseismic and/or tectonic effects in the Gediz Graben areally, deformations in the direction of Line of Sight (LOS) were determined by using the persistent scatterer interferometric synthetic aperture radar (PSInSAR) method. In order to determine movements in the LOS direction, TERRASAR-X Stripmap satellite radar images of the German Aerospace Center (DLR) were used. According to the evaluations obtained from the PSInSAR results, it is understood that while there are subsidences in the graben area of the Gediz Graben, there are uplifts in the north and south of the graben. The subsidence values in the graben were obtained to be approximately - 50 mm/year. This result indicates that in addition to creep movement of tectonic origin in the study area, the local soil characteristics and/or seasonal groundwater changes may also increase deformation in areas where deformation occurs.