An Updated Database and Spatial Distribution of Landslides Triggered by the Milin, Tibet Mw6.4 Earthquake of 18 November 2017

The M(w)6.4 earthquake on November 18, 2017 in Milin County, Nyingchi City, Tibet triggered thousands of landslides. By comparing visual interpretation of satellite images acquired shortly before and after the earthquake and field survey, we have created a new landslide database which includes 3 130 coseismic landslides, each with an area of 0.01 to 4.35 km(2). Six factors (elevation, slope angle, slope aspect, lithology, distance from the epicenter and distance from the seismogenic fault) were selected to correlate with the coseismic landslides. In addition, the area and density of landslides were counted as indicators. Results show that most landslides occurred where the elevation is between 2 000-3 000 m, with a 40 degrees-50 degrees slope angle and S, E or SE slope aspect, schist or gneiss lithologies, 10-15 km from the epicenter, and 5 km within the seismogenic fault. Most of the landslides, triggered by the M(w)6.4 earthquake, are concentrated near the seismogenic fault rather than at the epicenter, indicating that the seismogenic structure is more influential than the location of the epicenter. Our findings may differ from other landslide database due to temporal image acquisition, interference from weather, and image resolution.

Automated summary

This study analyzed the landslides triggered by the 2017 earthquake in Milin County, Tibet, and identified common characteristics such as elevation, slope angle, slope aspect, and lithology. Most landslides occurred near the seismogenic fault rather than at the epicenter.