Fig. 3

(a) Epicenter distribution. White circles indicate hypocenters located within a 3-km-wide swathe centered on the profile (Y = 0 km). Hypocenters distributed from 3 to 7 km from the profile (Y = 0 km) are shown by gray circles. The circles are scaled to earthquake magnitudes. Crosses indicate seismic stations used in the present study. (b) Vertical cross-section of inverted P-wave velocity along x-axis (Y = 0 km). Solid contour lines indicate V _p in km/s. The contour interval is 0.4 km/s. P-wave velocity is also indicated by a color scale in km/s. Areas with a resolution value less than 0.2 are painted white. Thick dashed lines indicate the Dedana fault inferred from seismic reflection profiling (Abe et al., 2008). Red triangle indicates surface trace of the range-bounding fault estimated by Abe et al. (2008). The arrow labeled Dedana F. at the top of the figure denotes the location of the surface trace of the Dedana fault. The planar distribution of aftershocks is marked by red arrows. A white line shows an asperity area with a slip larger than 1.5 m within the 3-km-wide swathe centered on the profile (Yokota et al., 2009). (c) Diagonal elements of a resolution matrix (V _p ). Solid contour lines indicate the resolution value. The contour interval is 0.2. The resolution value is also indicated by a gray scale.