2025年西藏定日M_(S)6.8地震地表破裂与震害特征分析  

Analysis of surface rupture and seismic damage characteristics of 2025 Dingri M_(S)6.8 earthquake in Xizang

作　　者：邢珂 黎昊 张乐乐 郁军建 彭一桂 彭博 向新建 窦杰 XING Ke;LI Hao;ZHANG Lee;YU Junjian;PENG Yigui;PENG Bo;XIANG Xinjian;DOU Jie(Badong National Observation and Research Station of Geohazards,China University of Geosciences(Wuhan),Wuhan 430074,China;Henan Earthquake Agency,Zhengzhou 450016,China;School of Earth Sciences,China University of Geosciences(Wuhan),Wuhan 430074,China;Key Laboratory of Geological Survey and Evaluation of Ministry of Education,China University of Geosciences(Wuhan),Wuhan 430074,China;National Engineering Research Center of Geographic Information System,China University of Geosciences(Wuhan),Wuhan 430074,China)

机构地区：[1]中国地质大学(武汉)湖北巴东地质灾害国家野外科学观测研究站,湖北武汉430074 [2]河南省地震局,河南郑州450016 [3]中国地质大学(武汉)地球科学学院,湖北武汉430074 [4]中国地质大学(武汉)国家地理信息系统工程技术研究中心,湖北武汉430074 [5]中国地质大学(武汉)地质探测与评估教育部重点实验室,湖北武汉430074

出　　处：《安全与环境工程》2025年第2期20-30,共11页Safety and Environmental Engineering

基　　金：国家自然科学基金面上项目(42477170);资源与生态环境地质湖北省重点实验室开放基金项目(HBREGKFJJ-202411)。

摘　　要：2025年1月7日,西藏日喀则市定日县发生M_(S)6.8地震,震中位于藏南裂谷体系中的申扎-定结断裂带登么错(丁木错)断层附近,震源深度为10 km,是近十年来致灾最严重的中强震事件。为深入了解地震造成的地表破裂与震害特征,基于合成孔径雷达差分干涉测量(differential InSAR,D-InSAR)技术,利用Sentinel-1降轨数据,通过地理编码获取定日地震同震形变场,对发震断层进行滑动分布反演,并结合无人机正射影像与野外勘察资料,开展震后地表破裂分布规律与震害特征分析。结果表明:沿LOS(line-of-sight,视线)向形变特征,震区最大沉降量和最大隆升量分别为0.65 m和0.75 m,东侧以隆升为主,西侧形变的影响范围显著大于东侧,地表破裂集中发生在登么错断裂西侧上盘区域;反演结果显示,发震断层具有高角度正断特征,滑动集中在地下0~14 km深度范围,在2~3 km深度处出现最大滑动量约为2.74 m,滑动矢量分析显示,断裂错动以正断运动为主;正射影像显示,地表破裂呈南北向2段展布,破裂长度为50~80 km,震中东南侧、登么错东岸以及尼辖拉昂水库以北地表破裂最为严重,地表裂缝宽度为0.1~4 m,台阶高度为0.1~2 m,最大位错地表破裂深度约为2~4 m。通过地球物理反演并融合多源遥感数据综合分析发现,本次地震的发震断层为登么错断裂,沿地表破裂带,地震造成了严重的房屋破坏、道路破坏,并诱发了崩塌、落石等次生灾害。系统分析地表破裂与震害特征,对完善青藏高原地震灾害评估体系具有重要意义。On January 7,2025,a M_(S)6.8 earthquake struck Dingri County,Rikaze,Xizang,with the epicenter located near the Dengmocuo fault of the Shenzha-Dingjie fault zone within the South Xizang Detachment System,at a focal depth of 10 km.To investigate co-seismic surface deformation and seismic damage characteristics,this study employs differential synthetic aperture radar interferometry(D-InSAR)using Sentinel-1 descending orbit data to derive the co-seismic deformation field and invert the fault slip distribution.Combined with unmanned aerial vehicle(UAV)orthophoto images and field investigations,the post-earthquake surface rupture patterns and seismic damage were analyzed.The results indicate that the line-of-sight(LOS)deformation reveals a maximum subsidence of 0.65 m and a maximum uplift of 0.75 m,with uplift dominating the eastern side while the western deformation zone is significantly larger.Surface ruptures are primarily concentrated on the hanging wall of the western Dengmocuo fault.The inversion results indicate that the seismogenic fault exhibits characteristics of a high-angle normal fault.The slip is concentrated within a depth range of 0 to 14 km,with the maximum slip of approximately 2.74 m occurring at a depth of 2 to 3 km.Analysis of the slip vectors reveals that the fault movement is predominantly characterized by normal faulting.Orthophoto images show that the surface rupture extends in three segments north-south for 50-80 km,with the most severe ruptures observed southeast of the epicenter,east of Dengmocuo,and north of the La’ang Reservoir in Nixia,where fracture widths range from 0.1 to 4 m,with vertical offsets of 0.1 to 2 m,and the depth of rupture at the largest faults ranging from about 2-4 m.Through geophysical inversion and multi-source remote sensing data fusion,this study identifies the Dengmocuo fault as the seismogenic fault and highlights severe building and road damage,as well as secondary hazards such as landslides and rockfalls along the surface rupture zone.These findings provide cri

关 键 词：M_(S)6.8地震 合成孔径雷达差分干涉测量(D-InSAR) 地表破裂 断层滑动分布反演 震害特征 

分 类 号：X43[环境科学与工程—灾害防治]