Fig. 1

The great Bihar–Nepal January 15, 1934, earthquake epicenter, red star (Chen and Molnar 1977), and the Gorkha April 25, 2016, epicenter, yellow star, in light of the present-day population density. The past and future great earthquakes ruptures correspond to the area in between the thick gray line with triangles corresponding to the Main Frontal Thrust and the white dotted line materializing approximately the position of the downdip end of the presently locked fault zone. The area delimited by the green polyline corresponds to the area affected by damages during the 1934 earthquakes (Isoseist VI MSK64 from this study). Red thick line with triangles corresponds to the minimum extension of the 1934 earthquake surface rupture (Sapkota et al. 2013) and red dotted line to minimum extension of the rupture at depth. The background image is a color-coded 2011 Landscan estimation of the population density