Abstract:
At 09:05 on January 7, 2025 (Beijing time), a magnitude 6.8 earthquake occurred in Dingri, Xizang Autonomous Region. The Institute of Geophysics, China Earthquake Administration launched a rapid earthquake emergency response after the earthquake, and organized researchers in relevant fields to estimate the source parameters, source mechanism, rupture process, and seismic radiation energy of the earthquake. The aftershock sequence was repositioned, and seismic intensity maps and InSAR coseismic deformation field simulations were conducted based on the source rupture process. The results indicate that the earthquake occurred on the west side of the Dengmocuo fault in the Shenzha-Dingjie fault system, with a main normal fault mechanism and a duration of about 20 seconds. It also exhibited asymmetric bilateral rupture characteristics, with the rupture mainly extending northward and most likely reaching the surface. Aftershocks are mainly distributed in a nearly north-south direction, with focal depths concentrated between 5~23 km. The seismic intensity in the extreme earthquake zone may reach seismic intensity IX or above, and the possible affected area may exceed
30000 km
2. This earthquake caused significant surface coseismic displacement, with a maximum horizontal displacement of 0.29 m and a vertical displacement of −0.75 m.