Brief report of landslides triggered by the 2022 Ms 6.8 Luding earthquake, Sichuan, China

Abstract

At 12:52 (UTC + 8) on September 5, 2022, an Ms 6.8 earthquake struck Luding County in Garzê Tibetan Autonomous Prefecture, Sichuan Province. This earthquake was characterized as a strike-slip event, with a focal depth of 16 km at 102.08°E and 29.59°N. As one of the pioneering emergent teams, the scientific personnel from the Institute of Geology, China Earthquake Administration immediately arrived at the site and conducted an extensive field investigation on earthquake-triggered landslides for half a month. The investigation results show that coseismic landslides are mainly distributed on both sides of the seismogenic fault and the Dadu River. Most landslides are concentrated within the regions with a seismic intensity of IX, such as the Moxi, Detuo, and Wanggangping towns. In particular, the Wandong and Xingfu villages have the highest abundance of landslides in the quake-affected area. These types of landslides are small- to medium-sized shallow landslides, collapses, and rolling stones with few larger-scale debris flows and slides. The loose deposits suspended at high position of a slope or in the valley of the quake-affected area are likely to slide again and generate new landslides or debris flows under the conditions of strong aftershock or heavy rainfall. Therefore, more attention should be paid to the long-term evolution of landslide activity and post-quake debris flows in the Luding area.