Overall-slow and dissipative rupture during the 2025 MW 7.1 Dingri, China earthquake

On 7 January 2025, the MW 7.1 Dingri earthquake in China ruptured a nearly north-south-trending normal-faulting fault within the southern Tibetan Plateau. We employed multi-array back-projection and finite-fault inversion methods to investigate the rupture process of the earthquake by integrating seismic and geodetic observations. Our results show that this earthquake ruptured a major asperity with a peak slip of 5.0 m, propagating northward at a low average speed of approximately 1.8−2.0 km/s (52%–58% of the shear wave velocity) over a main duration of approximately 25 s. The rupture initiated with very slow growth, accompanied by intense high-frequency radiation but limited slip. Notably, high-frequency sources were concentrated near the margin of the slip asperity. The energy-based average stress drop was estimated to be 5.2 MPa. The estimated radiation efficiency of this earthquake was 0.09, an extremely low value, indicating that most of the accumulated strain energy dissipated through thermal and fracturing processes. The diverse rupture signature of the 2025 Dingri earthquake highlights the physics nature of the intrinsic fault friction and stress/strength heterogeneities. Furthermore, the low rupture velocity, high stress drop, and low radiation efficiency consistently suggest that this earthquake was likely controlled by an immature seismogenic environment.