Insights into the Landslides Triggered by the 2022 Lushan Ms 6.1 Earthquake: Spatial Distribution and Controls

Abstract

On 1 June 2022, a magnitude Ms 6.1 (Mw 5.8) earthquake, named the 2022 Lushan earthquake, struck the southern segment of the Longmenshan fault zone, with an epicenter at 30.395°N, 102.958°E and a focal depth of approximately 12.0 km. To gain insight into the landslides triggered by this event and the characteristics of coseismic landslides in the Longmenshan fault zone, we collected multitemporal satellite images and carried out field investigations. The results reveal that the 2022 Lushan event triggered at least 1288 landslides over an affected area of 1470 km2. The total landslide area is 5.33 km2, and the highest landslide concentration reaches 22.3 landslides/km2. The landslide distribution has a hanging wall effect, and the right bank area of the Qingyi River, featuring deep-cutting gorges, is part of an area with obvious concentrated landslides; this area consists mainly of intrusive rocks, including granite, gabbro and hornblende. The coseismic landslides in the Longmenshan fault zone have hanging wall effects, and the landslides triggered by the 2022 Lushan event are distributed in higher and steeper areas.