Rupture mechanism and seismotectonics of the Ms6.5 Ludian earthquake inferred from three‐dimensional magnetotelluric imaging

Abstract A three‐dimensional (3‐D) resistivity model around the 2014 Ms6.5 Ludian earthquake was obtained. The model shows that the aftershocks were mainly distributed in a shallow inverse L‐shaped conductive angular region surrounded by resistive structures. The presences of this shallow conductive zone may be the key factor leading to the severe damage and surface rupture of the Ludian earthquake. A northwest trending local resistive belt along the Baogunao‐Xiaohe fault interrupts the northeast trending conductive zone at the Zhaotong‐Lianfeng fault zone in the middle crust, which may be the seismogenic structure of the main shock. Based on the 3‐D electrical model, combining with GPS, thermal structure, and seismic survey results, a geodynamic model is proposed to interpret the seismotectonics, deep seismogenic background, and deformation characterized by a sinistral strike slip with a tensile component of the Ludian earthquake.