Fig. 10

a Map of seismic events that occurred during the January 2001 to December 2012 period (Yano et al. 2017) superimposed on the S-wave velocity model horizontal slice at 3 km depth below sea level. Plotted hypocenters (black dots) are for earthquakes ranging from 0 to 6.5 in moment magnitude for depths shallower than 12 km. Blue arrow indicates the location of dense distribution of earthquake hypocenters along the western part of the Kii Mountainland. b Distribution of active faults superimposed on the S-wave velocity model horizontal slice at 3 km depth below sea level. Solid red lines represent active faults documented before this study (Research Group for Active Faults of Japan 1991). Thick dashed black closed-curve and a solid green line indicate the locations of the Niigata–Kobe Tectonic Zone (NKTZ) and the Arima-Takatsuki Tectonic Line (ATTL), respectively. Also shown are the locations of the Median Tectonic Line (MTL), Yamada Fault (YDF), Yamasaki Fault (YSF), Jumantsuji Fault (JMF, a member of the ATTL), Yabu Fault (YBF), Yagi Fault (YGF), Mitoke Fault (MTF), Hanaori Fault (HOF), Kizugawa Fault (KZF), Suzuka Fault (SKF), Yokkaichi Fault (YKF), Yanagase Fault (YNF), Uemachi Fault Zone (UFZ), Ikoma Fault Zone (IFZ), Tanba Block (TA), Hokutan Block (HO), and the Maizuru Block (MA). c–f Vertical sections showing the S-wave velocity variation beneath the profiles marked as solid magenta lines in b. Inferred locations of the Kyoto basin (KB), Ise basin (IB), Lake Biwa and the Biwako-seigan Fault Zone (BSFZ) and/or Niigata–Kobe Tectonic Line (NKTZ) along the profile are also shown on the vertical sections