## 1 Introduction
As a result of the study carried out between 1993 and 2000, a total of 10-20 cm subsidence was detected at the summit of the Tendurek volcano. Another study performed in the same area, reported by [41], aimed to detect the surface deformations of the Tendurek volcano using 41 Envisat images obtained from descending and ascending orbits between 2003 and 2020. In their study, using the small baseline subset technique, an 11 mm/yr subsidence was reported as a result of the narrowing of a sill located 4.5 km below the volcano peak. The most comprehensive study on surface deformations caused by volcanoes in Turkey was carried out by [42]. They aimed to determine the surface deformations that occur in 10 volcanic systems in Turkey using approximately 5000 Sentinel-1 images obtained from the ascending and descending orbits between 2015 and 2020. The study mainly focused on the seasonal snow cover that reduces the interferometric consistency encountered when monitoring the volcanoes with the InSAR technique and the atmospheric problems that cause misinterpretation of deformation. In the study, in which the multi-time InSAR technique was used, it was reported that no deformation on the cm scale was detected in the 10 volcanic systems in Turkey, which shows that there are significant differences among the results from the limited number of studies on the Tendurek volcano. Considering the studies above, the last detailed InSAR study of the Tendurek volcano was performed with data from 13 years ago [41]. In another subsequent research, it was examined on a national scale, and a detailed study of the Tendurek volcano was not carried out [42]. Therefore, the present study offers two novelties in terms of the literature. The first of these is the use of up-to-date data and a detailed study specific to the Tendurek volcano. The second innovative aspect of the present study is that the permanent scatterer interferometry technique is used for the first time in this volcano. In addition, the current surface deformation maps and findings obtained from the Tendurek volcano, as a result of this study, will contribute significantly to the literature. In this context, the main purpose of the present study is to determine the current surface deformations of the Tendurek volcano using StaMPS and to reveal the evolution of surface deformations over 5 years using the SAR time series. A total of 150 Sentinel-1 images were obtained from the ascending and descending acquisition geometries between 2018 and 2022, and surface deformations of the Tendurek volcano were determined using the SentiNel application platform (SNAP), snap2 stamps, StaMPS, and atmospheric InSAR noise-reduction toolbox (TRAIN). In addition, we applied two different atmospheric correction approaches (linear phase-based tropospheric correction and the General Atmospheric Correction Online Service (GACOS) for InSAR) to minimize the errors caused by atmospheric interactions. Finally, the current deformation velocity maps in the line-of-sight direction (LOS), the displacement time series, and the components of the deformation (horizontal vertical) in the LOS direction were calculated for the Tendurek volcano and its vicinity.