Fig. 6

Cumulative moment (top) and cumulative number of deep tremors (bottom) for a the SSE in 2015–2016 and b the 2018–2019 sequence. Cumulative moment in (a) shows that on the whole subfault area (gray rectangles in Fig. 4), whereas the cumulative moment in (b) shows those in three areas (“Bungo Channel”, “Oita”, and “Miyazaki”) depicted in Fig. 5b. Tremors in (b, bottom) correspond to those denoted as magenta circles in Fig. 5b. Orange arrows in (b) shows the acceleration phase of the SSE. Note that each trace in (b, top) is arbitrarily shifted in the vertical direction for clarity