Preliminary Study on the Characteristics of Landslides and Soil Liquefaction Triggered by the Dingri MS 6.8 Earthquake on January 7,2025,Southern Tibetan Plateau
Xu Yueren
Fu Guochao
Liang Zeyu
Hu Guiming
Zhou Xiaocheng
Shi Feng
Yao Yuan
Abstract：The rapid mapping of secondary effects triggered by strong earthquakes is crucial for understanding the disaster-causing mechanisms of mainshock events.The Tibetan Plateau,characterized by its higher altitude,sparse population,and challenging field conditions,presents significant difficulties for on-site investigations.Consequently,it is significant to analyze the distribution of earthquake-induced landslides and soil liquefaction utilizing post-earthquake emergency satellite imagery.We aim to systematically identify the spatial distribution characteristics of secondary hazards triggered by the MS6.8 Dingri earthquake on January 7,2025.We utilized emergency imaging data from high-resolution Chinese satellite images.We employed manual visual interpretation through a comparative analysis of pre-and post-earthquake imagery supplemented by field investigations.The following results are obtained:(1)The mainshock triggered 2 869 coseismic landslides,with two major concentration zones in the north and south.Approximately 60%of these landslides occurred in high-altitude regions between 5 000-6 000 m,predominantly manifesting as slope debris flows and collapses with limited effect for far away the residents.(2)The mainshock also induced about 400,000 soil liquefaction pits,primarily concentrated in the floodplains and low terraces of the Pengqu River at elevations of 4 100-4 300 m.These liquefaction sites are distributed across the Democuo Basin,Guojia Basin,and Dingjie Basin,with some occurrences in Quaternary tills at elevations reaching 5 200 m.The distribution pattern of coseismic landslides,primarily as slope debris flows in higher-altitude(about 5 000 m)areas,suggests a possible correlation with the topographic amplification effect.Meanwhile,the spatial extent of soil liquefaction,spanning three basins in the southern section of the Dingjie-Shenzha Rift system,indicates that single secondary-fault rupture event within a single basin can significantly impact other adjacent secondary-faulted basins,leading to severe secondary disasters,even the controlled faults without coseismal faulting.
Keywords：Tibetan PlateauDingri MS6.8 earthquakesoil liquefactionearthquakeslandslidesDingjie-Shenzha Riftsouthern Tibetan rift systems
Publication Date：2025-05-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：17( 1813-1829 )