Fig. 9

The contact of the Pacific slab with the overlying Philippine Sea slab or forearc crust. a Vertical cross-section of S-wave velocity along a line under Kanto in the inset map and b schematic figure showing the contact between the Philippine Sea and Pacific slabs (Nakajima et al. 2009b). c Across-arc vertical cross-section of S-wave velocity under western Hokkaido along a line in the inset map and d schematic figure showing the contact between the subducted forearc crust and the Pacific slab (Kita et al. 2010a). S-wave velocity is indicated by the color scale at the bottom