Fig. 6
From: Velocity structure in the crust beneath the Kyushu area
Plan views of (a) velocity perturbations for V p , (b) velocity perturbations for V s , and (c) V p / V s at each depth. The velocity perturbations are calculated with respect to the average of the estimated velocity values at each depth. Masking obscures areas of low reliability (the resolvability values smaller than 0.75). Red triangles mark active volcanoes and circles indicate the epicenters of the relocated events. The depth of each slice is marked in the upper left corner of each P-wave panel. Only those earthquakes lying within 2.5 km of the depth slice are shown. A (white dot) and B (gray dot) at the 30-km depth show the regions with low velocity and low V p / V s and with low velocity and high V p / V s , respectively.