Fig. 4

Comparison of observed phase velocities and the theoretical dispersion curves. The blue circles represent the observed phase velocities. The theoretical phase velocity dispersion curve of the fundamental mode of the Rayleigh wave by the best model is plotted with the red line. Other models with residual values smaller than twice the best model are indicated by gray lines. The theoretical dispersion curve based on the J-SHIS V2 model (Fujiwara et al. 2012) is also plotted by the green line