Detailed three-dimensional fault model of the 2022 Mw 6.6 Luding earthquake reveals seismic hazard potential in the southeastern Tibetan plateau

The detailed 3D fault model and further seismic rupture behavior analysis and fault mechanics simulation based on it are important and meaningful. A strong Mw 6.6 earthquake occurred in Luding, Sichuan, on 5 September 2022, the epicenter was located near the Y-shaped junction of the Xianshuihe Fault Zone (XSHF), the Longmen Shan Fault Zone (LMSF), and the Anninghe Fault Zone (ANHF). To date, a detailed 3D fault model has not been established for this earthquake, preventing a 3D Coulomb stress change (ΔCFS) calculation for further seismic potential analysis. Therefore, first we build a detailed 3D fault model of the earthquake and then we compute ΔCFS in the surrounding areas. Based on 3D modeling technics, we establish a 3D model of the main faults using previously published relocated earthquake catalog and focal mechanism solutions; including the Moxi segment (f₁) of the XSHF, the Daduhe fault (f₂) and two previously unknown faults (f₃ and f₄). The 3D ΔCFS indicates that the strike-slip mainshock of the Luding earthquake significantly triggered two M > 5 dip-slip aftershocks. Moreover, it caused a remarkable increase in ΔCFS and hence a notable enhancement in seismic hazard in the northern ANHF.