Fig. 4

a Estimated fault planes of the foreshocks (blue, light blue, and green lines) and a non-planar fault model of the main shock used in dynamic rupture simulations (orange lines). The fault planes of the foreshocks are the same as those shown in Fig. 2, and the main shock fault surface was built by connecting the estimated fault planes of the main shock shown in Fig. 2. Red star denote the epicenter of the main shock. b Assumed slip distributions of the three foreshocks in the map view (left panel) and in the view from the southeast (right panels). Black lines show triangular elements of a non-planar fault used in dynamic rupture simulations of the main shock. c How to generate the single fault interface (orange lines) from the two estimated fault planes of the main shock (black rectangles). The orange lines and the black rectangles are the same as the orange lines in (a) and the orange rectangles in Fig. 2a, respectively. The elements indicated by gray were removed at the connecting edges of the two fault planes, and fault elements were filled between both edges forming a non-planar fault segment