2025年1月7日西藏定日Ms6.8級地震InSAR同震形變探測與斷層滑動分布反演

InSAR coseismic deformation detection and fault slip distribution inversion of the 6.8 earthquake in Dingri， Tibet on January 7， 2025

InSAR coseismic deformation detection and fault slip distribution inversion of the 6.8 earthquake in Dingri， Tibet on January 7， 2025

LI Yusen'，LI Weile12，XU Qiang1，2，LU Huiyan1，HE Guoqing'， FANLuzhen’，QINJiasong' 1. State Key Laboratory ofGeohazard Prevention and Geoenvironment Protection， Chengdu University of Technology，Chengdu 610059，China； 2.LaboratoryofLandslideRisk Early-WarningandControl，Chengdu 61oo59，China

Abstract： An 6.8 earthquake occurred in Dingri County， Shigatse City， Tibet Autonomous Region on 7 January

2025，which is the largest earthquake to have occurred in recent years.The macro-earthquake epicenter was located near the Shenzha-Dingjie fault Zone at the junction of the Tibetan Plateau and the Indian Plate.To understand the characteristics of this earthquake，we determined the coseismic deformation fieldof this earthquakebased on InSAR technology，using the data from Lutan-1 （ascending orbit）and Sentinel-1 （descending orbit）.These data were used to invertthe sliding distributionof theseismic fault，andtocalculate thecoseismiccoulombic stresschangesatdifrent depths in the region. The results show that the surface deformation caused by this earthquake is up to 160×100km and the deformation is concentrated on the west side of the Dengmecuo fault， with a maximum deformation of -1.538m along thesatellite'slineof sight，andamaximumvertical deformationof 0.68m .Theinversion results show that theruptured faults are mainly positively faulted，witha smallamount of strike-slip，and the slips are mainly located in the range of 0～14km below ground. The maximum amount of sliding is about 4.73m .Based on a comprehensive evaluation of the inversion results and geological data， we find that the Dengmeco fault generated this earthquake.Thecolumb stresschange at diffrent depths shows that the south Tibetan sliding disassemblage system fracture Zone，the Shenzha-Dingjie fracture zone，and thecentral part ofthe Zhada-Lazi-Qiongduojiang fracture Zone are all in the stress-loading Zone，which need to be better understood and studied.

Key words：Dingri earthquake；differential interferometric synthetic aperture radar；coseismic deformation；slip distribution

2025年1月7日9時5分，西藏自治區(qū)日喀則市定日縣發(fā)生 級地震，宏觀震中位于 ， ，震源深度 10km（ 中國地震局，2025），震中附近臺站記錄到的最大儀器烈度為IX度，定日縣縣城及周邊震感明顯；截至2025年1月7日19時，地震共造成126人遇難，188人受傷，3609戶房屋倒塌（新華網(wǎng)，2025），成為繼2023年12月18日甘肅省積石山縣 級地震后死亡人數(shù)最多的地震；主震發(fā)生24小時內(nèi)，震中區(qū)域接連發(fā)生18次三級以上的余震，最大余震為2025年1月7日10時14分發(fā)生的 級地震，截至2025年1月14日08時00分，共記錄到3614次余震（央視網(wǎng)，2025），余震大致以南北走向分布，暗示此次地震的發(fā)震斷層可能為一條南北走向的斷層。（剩余6625字）