Figure 1

The upper figure displays the selected three subduction zones in the Pacific-rim scale. The blue chain lines represent the plate boundaries in the NUVEL-1 model (DeMets et al., 1990), and the green broken lines represent those in a modified model (Bird, 2003). The lower figures illustrate the approximate locations of the SSE areas (orange circles) and source areas of nearby large earthquakes (shaded ovals) at the same scale. (a) The Boso zone (Hirose et al., 2012; Ando, 1971). (b) The northern Cascadia zone (Szeliga et al., 2008; Leonard et al., 2010). (c) The Yaeyama zone (Heki and Kataoka, 2008; Nakamura, 2009a). We use Generic Mapping Tools (Wessel and Smith 1995) to draw the maps.