Seismic and environmental controls on slow-moving landslides: Insights from the 2008 Wenchuan Earthquake

Abstract

Earthquakes can initiate slow-moving landslides and cause them to transition into rapid failures. Although observations are limited, the literature suggests that strong earthquakes are more likely to trigger nearby failures, while smaller earthquakes may increase susceptibility. However, understanding the role of seismic disturbances requires considering other environmental conditions. This study focuses on the 2008 Mw 7.9 Wenchuan earthquake, using a data-driven multivariate approach to analyze slow-moving landslides. Our findings highlight topographic relief, road proximity, river distance, average monthly precipitation, lithology, and distance to the earthquake surface rupture as key factors. While the distance to the surface rupture is inversely related to landslide occurrence, it is the least influential variable, suggesting that most slow-moving landslides near the rupture may not have failed during the earthquake. Our finding also suggests that persistent disturbances from road networks may be as significant as the impact of a strong earthquake in influencing the existence of slow-moving landslides.