Fig. 7

(a) Depth section of the deep section and (b) interpretation of the section. The section is converted from the time section on the basis of the velocity structure obtained in the velocity analysis. The solid lines in (b) indicate faults in the section. The hatched area covering the reflectors, at and around, a depth of 3 km is interpreted as the top of the magma body. The red circle denotes the location of the pressure source during eruption, as obtained by Kohno et al. (2008). The dashed green square shows the shallow section (shown in Fig. 8).