The 2025 Mw 7.1 Dingri Earthquake, Southern Tibet: Normal Faulting Associated With Indian Slab Tearing?

Abstract The 2025 Mw 7.1 Dingri earthquake underscores the ongoing seismic risk within the Himalayan‐Tibetan collision zone. Utilizing full‐waveform inversion, we constructed a three‐dimensional subsurface velocity model around the epicentral region. Our imaging reveals a pronounced high‐velocity (HV) anomaly extending northward from the Himalayan Block into the Lhasa Block, spatially coincident with surface rifting structures. The earthquake hypocenter is situated at the boundary between this anomaly and an adjacent low‐velocity (LV) region within the Lhasa Block. At uppermost mantle depths, a HV, low Poisson's ratio anomaly beneath the epicenter corresponds to the subducting Indian lithospheric slab, which is laterally bordered by LV zones characterized by high Poisson's ratios. These observations are consistent with along‐strike tearing of the Indian slab and localized asthenospheric involvement, producing adjacent mechanically weaker regions. We propose that slab tearing induced extensional stresses, driving surface rifting and triggering the Dingri earthquake. Our results offer a unified framework to explain major normal‐faulting earthquakes in southern Tibet and highlight the fundamental influence of slab tearing on regional seismicity and tectonic evolution.