An overview of the spatiotemporal patterns of land displacements in Western Greece

Understanding and monitoring geohazards, including not only abrupt phenomena but also gradual land displacements, is of key scientific importance with socioeconomic implications. Satellite remote sensing techniques, such as Interferometric Synthetic Aperture Radar (InSAR), allow for detailed estimation of land displacements. Here, we focused on the area of Western Greece, characterized by numerous faults and high seismicity, and we quantified the spatiotemporal patterns of land displacements across the study domain from 2018 to 2022. We used the Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) technique to process Sentinel-1 InSAR data following the Stanford Method for Persistent Scatterer (StaMPS) workflow. Vertical and horizontal land displacements across the study area were estimated and compared with estimates from the European Ground Motion Service (EGMS). The magnitude of these displacements was further scrutinized at the annual and sub-annual time scale by examining the EGMS-derived time series of vertical and horizontal land motion at selected areas with critical infrastructures. The increasing availability of InSAR data, in tandem with advancements and ease in data handling and processing, facilitate the deployment of such remote sensing techniques, and, when combined with observations from ground networks, could assist towards comprehensive monitoring of land processes and infrastructures.