The effects of earthquakes with different rupture patterns in the main Himalayan thrust on deformation and stress changes in the Himalayan orogenic belt and Southern Tibetan Plateau

The relationships between co-seismic slip and surface deformation under different rupture patterns along the Main Himalayan Thrust remain poorly understood. We established three idealized fault slip models to analyze co-seismic and post-seismic deformation, stress changes, and their impact on faults in Southern Tibetan Plateau (STP). The results show that three types of earthquakes produce distinct mountain-building deformation effects. Full-scale rupture events cause a mutual offset between co-seismic subsidence and interseismic uplift deformation in the Great Himalaya, while post-seismic vertical deformation occurs in the opposite direction to that induced by co-seismic slip. In the other two models, vertical deformation is concentrated in the Lesser Himalaya. The uplift deformation caused by blind ruptures plays a crucial role in the formation of the Kathmandu Basin. Stress perturbations on faults in STP are not influenced by rupture patterns (i.e. whether surface rupture occurs), which differs from stress transfer patterns observed in epicentral areas. The stress change pattern in STP effectively explains the distribution characteristics of co- and post-seismic Coulomb stress changes induced by the 2015 Gorkha earthquake. Among them, stress changes in the east–west direction play a driving role in the rupture of nearly north–south striking rifts.