Influence of earthquakes on landslide activity in the permafrost regions of the Qilian Mountains, China

Abstract Landslide activity in the Qilian Mountains is increasing due to permafrost thawing driven by global warming, where also developed numerous reverse strike‐slip active faults with frequent and high‐intensity earthquakes. While many studies have examined the influence of climate change on landslide activity in permafrost regions, the role of earthquakes in modulating landslide behaviour in such environments remains less well quantified. In this study, Interferometric Synthetic Aperture Radar (InSAR) was employed to investigate whether the 2022 Menyuan earthquake induced post‐seismic acceleration of landslides in permafrost areas. The results show that the earthquakes exerted a pronounced impact on landslide deformation, producing an instantaneous subsidence of approximately 24.83 mm, which is substantially larger than the maximum annual displacement observed before the event. Moreover, post‐seismic landslide velocities increased by up to 21 mm/year, and the seasonal deformation amplitude after the earthquake was approximately twice that observed during the pre‐seismic period. To further elucidate the mechanisms underlying these responses, we quantified the dominant controlling factors of landslide deformation using a Geographic Detector approach. The results indicate that landslides located closer to active faults exhibit larger displacement rates, although no clear hanging‐wall or footwall effect was observed. Landslides at higher elevations, particularly above 3,450 m, are more susceptible to deformation. Importantly, we find that landslides under colder ground temperature conditions are more strongly affected by seismic shaking and tend to exhibit larger post‐seismic deformation, with a 0.2°C decrease in ground temperature corresponding to an increase of approximately 5 mm/year in displacement rate. These findings provide new quantitative insights into the role of earthquakes in controlling landslide activity in permafrost regions and highlight the importance of permafrost thermal conditions in modulating post‐seismic landslide behaviour.