Fig. 1

Tectonic map of the southern Chile subduction zone. The map shows the area within the black dashed boxed area in the inset. The area surrounded by blue dashed lines is the horizontal projection of the 3-D model region. The thick black barbed line represents the plate boundary at the Earth’s surface (Bird 2003), and the thin black line denotes the upper surface of the subducted Nazca plate with a contour interval of 20 km (Hayes et al. 2018). The yellow lines indicate the current seafloor age of the Nazca plate (Seton et al. 2020). The red solid line and orange solid line represent the coseismic slip distributions of the 1960 Valdivia earthquake (Mw9.5) and 2010 Maule earthquake (Mw8.8) with contour intervals of 10 m and 5 m, respectively (Ho et al. 2019; Moreno et al. 2012). The red solid triangles denote volcanoes. The purple arrows represent the convergence rates of the Nazca plate with respect to the South American plate calculated based on ITRF2014 (Altamimi et al. 2016). The bathymetry and topography data are obtained from ETOPO1 (Amante and Eakins 2009). The map was created by using Generic Mapping Tools (GMT) (Wessel and Smith 2016)