2025年1月7日西藏定日Ms6.8级地震InSAR同震形变探测与断层滑动分布反演
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时5分，西藏自治区日喀则市定日县发生 级地震，宏观震中位于 ， ，震源深度 10km（ 中国地震局，2025），震中附近台站记录到的最大仪器烈度为IX度，定日县县城及周边震感明显；截至2025年1月7日19时，地震共造成126人遇难，188人受伤，3609户房屋倒塌（新华网，2025），成为继2023年12月18日甘肃省积石山县 级地震后死亡人数最多的地震；主震发生24小时内，震中区域接连发生18次三级以上的余震，最大余震为2025年1月7日10时14分发生的 级地震，截至2025年1月14日08时00分，共记录到3614次余震（央视网，2025），余震大致以南北走向分布，暗示此次地震的发震断层可能为一条南北走向的断层。（剩余6625字）