2025年1月7日西藏定日Ms 6.8地震震源机制InSAR反演及强地面运动快速模拟  

Source Parameters and Rapid Simulation of Strong Ground Motion of the Ms 6.8 Earthquake on January 7,2025 in Dingri(Xizang,China)Derived from InSAR Observation

作　　者：王楠 李永生 申文豪 姜文亮 李强 焦其松 WANG Nan;LI Yongsheng;SHEN Wenhao;JIANG Wenliang;LI Qiang;JIAO Qisong(National Institute of Natural Hazards,Ministry of Emergency Management of China,Beijing 100085,China)

机构地区：[1]应急管理部国家自然灾害防治研究院,北京100085

出　　处：《武汉大学学报(信息科学版)》2025年第2期404-411,共8页Geomatics and Information Science of Wuhan University

基　　金：国家自然科学基金(42374039);应急管理部国家自然灾害防治研究院基本科研业务专项(ZDJ2024-18)。

摘　　要：北京时间2025-01-07,中国西藏自治区日喀则定日县发生了Ms 6.8地震,造成大量人员伤亡。地震发生在青藏高原拉萨地块内部,为快速获取此次地震的发震构造和准确理解震源机制,基于陆探1号(Lutan-1,LT-1)卫星升轨数据和Sentinel-1卫星降轨数据提取了本次地震的同震形变场,并以此作为约束资料对发震断层几何参数和滑动分布进行反演。同震形变场显示,发震地区以垂直变形和东西向伸展变形为主要特征,视线向最大变形量达到了2 m。反演结果表明,此次地震发生于一条走向为187°、倾角为40°的正断层,断层最大位错量达6 m,矩震级达到了Mw 7.1。基于反演断层滑动模型模拟地震烈度,结果显示此次地震最大烈度可达Ⅸ度。综合使用InSAR地震同震形变场和两步法断层参数反演算法快速获取地震震源机制和破裂参数,可为地震应急救援、烈度估算和震害分析等提供快速准确的数据支持。Objectives:On January 7,2025,an Ms 6.8 earthquake struck Dingri County,Shigatse City,Xizang Autonomous Region,China,resulting in numerous casualties.This earthquake took place within the Lhasa block of the Qinghai-Tibet Plateau.To swiftly ascertain the seismogenic structure of this earthquake and gain a precise understanding of its source mechanism,this study utilized ascending data from the Lutan-1(LT-1)satellite and descending data from the Sentinel-1 satellite to extract surface coseismic deformation.Methods:This de⁃formation data served as constraint information for the inversion of geometric parameters and slip distribution of the seismogenic fault.Results:The findings reveal that the earthquake-affected areas primarily exhibited near east-west extension deformation,with the maximum deformation in the line of sight direction attaining 2 m.The inversion outcomes demonstrate that the earthquake occurred on a normal fault with a strike of 187°and a dip angle of 40°,exhibiting a maximum slip of 6 m and a simulated moment magnitude of 7.1.By simulating earthquake intensity based on the estimated fault slip model,it was found that the maximum intensity of this earthquake could reach levelⅨ.Conclusions:The integrated application of interferometry synthetic aperture radar seismic coseismic deformation field and a two-step fault parameter inversion algorithm achieved a rapid acquisition of the earthquakes source mechanism and rupture parameters.This approach offers swift and precise data support for earthquake emergency response,intensity estimation,and damage analysis.

关 键 词：定日地震 InSAR反演 同震形变 震源机制 强地面运动 

分 类 号：P237[天文地球—摄影测量与遥感]