Figure 8

(a) Example of seismogram (N–S component) used for multiple lapse time window analysis (MLTWA) showing three-time windows (0–15 s, 15–30 s, and 30–45 s) starting at the arrival of S-waves. The time bar with 10 s denotes the coda normalization window (CNW). Its center (t_c) denotes a fixed reference time (45 s lapse time). (b) Example of a MLTWA fit of the normalized energy recorded of the Kumamoto earthquake in the 1–2 Hz frequency band. The theoretical curves based on the plus signs, triangles, and circles obtained from the first, second, and third windows in the left diagram, respectively, were fitted using Monte Carlo simulations³³. (c) Residual map corresponding to (b). The areas normalized by the minimum residual value (star), = \({{\varvec{M}}}_{{\varvec{f}}}\left({{\varvec{\eta}}}_{{\varvec{s}}},{{\varvec{\eta}}}_{{\varvec{i}}}\right)/{{\varvec{M}}}_{{\varvec{f}}}\left(\widehat{{{\varvec{\eta}}}_{{\varvec{s}}}},\widehat{{{\varvec{\eta}}}_{{\varvec{i}}}}\right)\)1.01, are plotted with dark rhombuses as the F test confidence zone at the 60% level.