Fig. 5

Tidal response of TDWs. a Normal stress on the megasplay fault, calculated from the method described by Yabe et al. (2015) (Yabe et al. 2015). Normal stress values within the light-blue rectangle were used to calculate the stacked envelope function in Fig. 6. The red lines represent the thresholds at high and low tides. b Number of stacked 1-h TDWs within 5-day moving averages at (black line) high tide, (blue line) middle tide, and (red line) low tide. c The first two panels on the left represent 5-day stacked TDWs during Julian days 1–60 in 2019 for high and low tides at OBS03. The frequency band is 9–15 Hz. The right panel displays the time shift of each segment between the high and low tides, and the time window of the segment and increment are 0.2 and 0.1 s, respectively. d Same as panel c, but for OBS04