Fig. 1

Map of Japan and surrounding regions, showing the location of the study area (Mizunami). The location of the Izumo area (Sawada et al. 2013) is also shown. Southwest (SW) Japan and Northeast (NE) Japan rotated clockwise (CW) and counterclockwise (CCW), respectively, during the late stage of opening of the Japan Sea (see text). Base map was generated using ‘Map-It’ (http://woodshole.er.usgs.gov/mapit/)