Investigation of cadastral point coordinate differences in İzmir region after the Samos earthquake 30 October 2020 ( Mw= 6.9)

In this study, the changes in the coordinates of 18 cadastral sites located within the borders of İzmir after the 30 October 2020 (Mw: 6.9) Samos earthquake were investigated. For this purpose, GNSS measurements were carried out at these sites in 2021 and 2022. All data were processed with GAMIT software. The changes in each site were calculated by taking the coordinate differences before and after the earthquake at all sites. When the coordinate changes in the years 2020-2021 and 2021-2022 after the earthquake were examined, differences of 1-40 and 1-35 mm were calculated, respectively. When the results are examined, it is evaluated that both the establishment of new sites should be avoided and updates should be made in the cadastral sites due to the velocity differences in the post-earthquake periods.