(a) Map view of the Gonghe Basin. The upper left inset shows the location of the Gonghe Basin in the broader Tibetan Plateau (red square). Cyan circles show epicenters of earthquakes during January 2009–July 2021 collected from the National Earthquake Data Center ( NEDC ). Beachballs represent focal mechanisms that mark M≥ 5 aftershocks of the 26 April 1990 Ms 7.0 event (compiled from Diao et al., 2025 ). All historic large events show reverse faulting mechanism, consistent with the collision be