Landslides triggered by the 2022 Ms. 6.8 Luding strike-slip earthquake: An update

Abstract

In this study, we established an updated coseismic landslide inventory of the 2022 Ms. 6.8 Luding earthquake. This version contains over 16,000 hand-digitized landslides with a total landslide area of 43.2 km2. We compared the spatial distribution of landslides and topographic, seismic, and geological factors on both sides of the seismogenic fault. The results show that the coseismic landslides of the Luding earthquake were mainly distributed along both sides (SWW and NEE blocks) of the seismogenic fault, with more landslides concentrated on the west side (SWW block). Compared to the NEE block, landslides on the SWW block are more likely to occur in areas characterized by higher elevations and reliefs. Otherwise, we observe an exponential decrease in both landslide area density and number density as the distance from the seismogenic fault increases, and the proximity to the fault is positively correlated with landslide size. Finally, we explored the relationship between landslide distribution and slip patterns by examining the detailed rupture characteristics of the Luding earthquake. Our analysis indicates that density patterns of coseismic landslides closely track the distribution of fault slip. The landslide abundance area corresponds to the area with the largest slip displacement of the surface rupture. The more the rupture extends into the shallow portion of the fault plane, the more landslides occur.