The Japanese archipelago is actively undergoing seismic shifts due to interactions between the oceanic plate and the continental plate. At the plate boundaries located directly beneath areas of Japan (especially the Bungo Channel, Tokai and Boso-Oki regions), slow slip events (SSEs) occur, which involve gradual aseismic slipping taking place at a recurrence interval of several years.
Click here for original story, New insight into the relationship between slow slip events and the build-up and release of tectonic strain
Source: Phys.org