Fig. 8

a Evolution of the energy release for three ETS events with nearly identical start points. Each snapshot encompasses the time period shown in the upper left corner and displays the cumulative seismic energy release during that period. Black rectangles represent the locations of high-energy patches on the subducting Philippine Sea plate interface. Red stars indicate the start point of the ETS events. b Cumulative seismic energy release curves of the three ETS events. c, d Comparison of cumulative seismic energy release during the initial parts of the three ETS events in which c the start of the rupture in patch B and d the time of the first tremor event within the period of semblance analysis (Table 1) serves as the zero point on which the curves are aligned so as to better compare the earliest phase of the ETS events