Fig. 7

Vp/Vs structure around the southern termination of the 2016 rupture. The symbols for the aftershocks indicate the same occurrence times as those in Fig. 6. a Vp/Vs structure at 10 km depth. The solid rectangles represent the surface expression of the source fault planes for the mainshock in Asano and Iwata (2016). The dashed black line and black arrow indicate the southern termination of rupture that was estimated in this study. The solid and dashed red lines denote the active faults determined by RGAF (1991) and HERP (2013), respectively. FT Futagawa segment, UT Uto segment, UN north coast of Uto Peninsula segment, TS Takano–Shirahata segment, HN Hinagu segment. b Vertical section of the Vp/Vs structure along the Hinagu fault zone (y = 0 km). The hypocenters located in a range of y = 0–2 km are plotted. The black contour line shows the projected slip distribution (> 1 m) of the mainshock (Asano and Iwata 2016). The dashed black line and black arrow indicate the southern termination of rupture that was estimated in this study. c Depth ranges of the hypocenters plotted in (b) at a 2-km interval. The top and bottom of each vertical line indicate D10 and D90, respectively, and each diamond indicates D50, where D10, D50, and D90 represent 10, 50, and 90% of the events occurred above those depths in each 2-km interval