2018年大阪府北部地震(M6.1)前後の地殻変動

Abstract

We clarified crustal deformation before and after the 2018 M6.1 northern Osaka earthquake using GNSS, InSAR, and extensometers at Abuyama Observatory. The earthquake occurred in a strain concentration zone in which the high strain rate was observed before the earthquake by GNSS. Small coseismic displacement was observed by GNSS and was reproduced by dislocation fault models. Distinctive pre-, co-, and post-seismic strain was observed by the extensometers located ~5 km away from the epicenter. The strain in each period showed different directions of the principle strain and cannot be explained by simple elastic dislocation models. We constructed new GNSS stations across the Arima-Takatsuki fault zone after the earthquake. Combining new stations, stations operated by collaborative institutions, and existing GEONET stations, a detailed deformation in the Kyoto-Osaka-Kobe area will be clarified in a few years.