摘要
2025年1月7日西藏定日县发生6.8级地震,造成了重大的人员伤亡,此次地震的发震断裂为申扎-定结裂谷系南部的登么错断裂。本文通过遥感影像解译、无人机航拍、现场调查结合前人研究,对此次地震同震地表破裂与湖岸地表变形的特征及成因展开了讨论。研究表明,同震地表破裂断续分布于羊姆丁错姆至朋曲河一带,总体沿先存断层陡坎展布,垂直位错在尼辖错东北最大,达2.5~3.0 m,古荣村及羊姆丁错姆一带为50~80 cm,古荣村以南小于25 cm。湖岸地表变形展布于登么错东岸,宽达100~300 m,多表现为拉张裂隙和挤压土堆,为地震动与重力滑塌共同作用所致。此次地震还反映了断裂带复杂的非均匀应力分配与破裂传播过程,余震分布进一步表明断裂深部存在相互作用与影响,这种深部构造的复杂性显著增加了该地区地震活动的不确定性。
On January 7,2025,a magnitude 6.8 earthquake struck Dingri,Xizang,resulting in significant casualties.The seismogenic fault responsible for this event is the Dengmecuo Fault,located in the southern segment of the Shenzha–Dingjie rift system.This study investigates the characteristics and formation mechanisms of the co-seismic surface rupture and associated shoreline deformation using remote sensing imagery,UAV aerial photography,field surveys,and prior research.Findings indicate that the co-seismic surface rupture is discontinuously distributed from Yangmudincuomu Lake to the Pengqu River,generally following pre-existing fault scarps.The maximum vertical displacement,measured at 2.5 m to 3.0 m,occurs northeast of Nixiacuo.In contrast,vertical displacements in the regions around Gurong Village and Yangmudincuomu Lake range from 50 cm to 80 cm,decreasing to less than 25 cm south of Gurong Village.Shoreline deformation is observed along the eastern margin of Dengmecuo Lake,spanning a width of 100 m to 300 m.This deformation primarily consists of tensile fissures and pressure-induced soil mounds,attributed to the combined effects of seismic shaking and gravitational collapse.The earthquake also reveals a complex pattern of non-uniform stress distribution and rupture propagation within the fault zone.Aftershock distribution further suggests deep fault interactions and structural complexity,which significantly contribute to the uncertainty of seismic activity in the region.
作者
徐伟
刘志成
蔡晓光
邹子南
Xu Wei;Liu Zhicheng;Cai Xiaoguang;Zou Zinan(China Earthquake Disaster Prevention Center,Beijing 100029,China;Institute of Geology,China Earthquake Administration,Beijing 100029,China;Power China Chengdu Engineering Corporation Limited,Chengdu 610072,China)
出处
《震灾防御技术》
北大核心
2025年第2期221-232,共12页
Technology for Earthquake Disaster Prevention
基金
西藏自治区科技重大专项课题(XZ202201ZD0003G)
大震震源探查(DZ5WTT202305)
国家自然科学基金(42102267)。
关键词
定日6.8级地震
登么错断裂
地表破裂
地表变形
Dingri M_(S)6.8 earthquake
Dengmecuo fault
Surface rupture
Surface deformation
