Surface displacements of the 2014 Cephalonia (Greece) earthquake using high resolution SAR interferometry

The island of Cephalonia (Western Greece), was struck by two strong seismic events, with magnitudes Mw = 6.0 and Mw = 5.9 which occurred on Jan. 26, 2014 and Feb. 3, 2014 respectively. The first event was located near Argostoli’s village, whereas the second one was located at the north part of Livadi village. These two strong seismic events were followed by smaller aftershocks provoking extensive crustal movements and structural damage effects. Differential Synthetic Aperture Radar Interferometry (DInSAR) is a powerful remote sensing tool for ground motion monitoring. Since the last two decades, DInSAR is widely used in a variety of applications including natural hazards such as earthquakes. In 2007, a high resolution X-band satellite namely TerraSAR-X was launched. Due to its short revisit cycle of 11 days and its short wavelength, it has a good potential to capture faster surface movements. This study refers to the application of the DInSAR using TerraSAR-X strip map data to monitor the co- and post-seismic surface deformation caused by the second seismic event. Using DInSAR methodology, three differential interferograms were calculated showing the displacement trend of the region, before and after the earthquake. Results demonstrate that the main part of the island shows stability to low uplift whereas in the western part a significant deformation pattern is observed. The findings permit a better understanding and identification of the local tectonic setting of the study area and the investigation of the reasons that some settlements were strongly affected by this seismic activity.