Surface Displacement Around the Ezu Lake and the Suizenji Area Associated with the 2016 Kumamoto Earthquake

Abstract

The 2016 Kumamoto earthquake caused crustal deformation along the ruptured fault. In addition, local surface displacements, which cannot be explained only by the mainshock fault movement, have also been reported previously. In this study, we report local post-seismic surface displacement around the Ezu lake and the Suizenji area using synthetic aperture radar interferometry of ALOS-2/PALSAR-2 data. Based on the hydrological structure beneath the area and the observed drawdown of the water level, the local displacement is likely caused by the groundwater migration associated with the 2016 Kumamoto earthquake.