Fig. 5: Schematic cross-sectional views beneath the Kii Peninsula before and after the occurrence of SST.
From: Effects of episodic slow slip on seismicity and stress near a subduction-zone megathrust
The stress state of upper-plane events in the slab changes after SST times. Red and green arrows depict the orientations of maximum compressional stresses. Fluids move from the oceanic plate into the plate boundary, as suggested by the high b-value peak for the upper-plane events 1.5 months before SST times. Increased fluid on the plate boundary reduces the degree of plate coupling between the overlying and subducting plates.
