Fig. 9

Scatter plots showing amplitude decay of the observed and synthetic seismic wave. a Polarization amplitudes from observation for three stations (Station 1145 in blue, 1149 in orange, and E.KW8M in green) are plotted against characteristic frequency. b Polarization amplitudes from observation for all stations are plotted against distance from Station 1145, which is almost the same location as the center of energetic supporters. Amplitudes are normalized by amplitude at Station 1149. Colors of dots represent characteristic frequencies of seismic waves. Black curves represent r⁻¹ and r⁻² decay, which corresponds to surface waves and body waves, respectively, for references. c, d Show synthetic results for Model 1 same as in a, b, respectively. e, f Show synthetic results for Model 2 same as a, b, respectively