Revisiting the seismic hazards of faults surrounding the 2022 Ms6.8 Luding earthquake, Sichuan, China

The occurrence of the Ms6.8 Luding earthquake on 5 September 2022 filled the seismic gap in the southeastern segment of the Xianshuihe fault zone and transferred stress to the surrounding faults, which attracted much more attention to the seismic hazard. In this study, we calculate the coseismic Coulomb stress changes caused by the Ms6.8 Luding earthquake and analyze its relationship with the relocated aftershocks, and further explore the stress evolution before the Luding earthquake and seismic hazards on the surrounding faults after it. The results show significant coseismic Coulomb stress increases in the northern Anninghe fault zone and the coseismic unruptured section of the southeastern Xianshuihe fault zone. Aftershocks are highly correlated with the positive coseismic Coulomb stress change, wherein eight out of eleven aftershocks of M >= 3.0 occurred in areas with significant stress increases ranging from 0.03 MPa to 0.44 MPa, indicating the triggering effect. The Moxi fault experiences co- and post-seismic Coulomb stress changes due to historical M >= 7.0 strong earthquakes since 1515, which help understand the seismogenic mechanism of the Luding earthquake. Moreover, the Luding earthquake advanced the potential earthquakes in the northern section of the Anninghe fault zone by approximately 60 years, further highlighting the potential seismic hazards.

Automated summary

The occurrence of the Luding earthquake in September 2022 filled a seismic gap and transferred stress to surrounding faults. The study shows significant coseismic Coulomb stress increases and a correlation between aftershocks and positive stress change. The Luding earthquake also advanced potential earthquakes in a specific fault zone by approximately 60 years.