Fig. 6

Occurrence times and source regions of great Nankai Trough earthquakes during years S2000–S3400 of our simulation. Stars indicate rupture initiation points. Blue lines indicate rupture segments with large slips (> 5 m) near the trough axis. Red horizontal lines in area Z indicate Hyuganada earthquakes with M_w ~ 7.5; green lines in areas E and Z indicate M_w 6-class earthquakes. Numbers in parentheses indicate years between successive earthquakes. Annotation on the right side lists the magnitudes of Nankai and Tokai/Tonankai earthquakes; the superscripts indicate the event number, corresponding to the plots in Figs. 5 and Additional file 1: S2. Mega-earthquake magnitudes are shown in white on red background. The numbers in brackets indicate the time lag in years between the Tokai/Tonankai and Nankai earthquakes of event pairs; event pairs with superscripts b, c, and d mean time lags of 2 days, 1 day, and 2 weeks, respectively. The arrows indicate the occurrence order of great earthquakes, and the open arrows indicate the cases where the Nankai earthquake preceded. The earthquake types, shown on the right, are described in the text. Their colors correspond to Fig. 5. Question marks indicate rupture patterns that cannot be classified into any of six representative earthquake types shown in Fig. 5