西藏中北部改则幅(I45)全新世断层典型遥感影像  

TYPICAL REMOTE SENSING IMAGES OF HOLOCENE FAULTS IN GAIZE PAN(I45)IN TIBET

作　　者：白其乐格尔 沈军[1,2] 肖淳 戴训也 BAI Qilegeer;SHEN Jun;XIAO Chun;DAI Xun-ye(Key Laboratory of seismic Dynamics of Hebei Province,Sanhe,Hebei 650201,China;Institute of Disaster Prevention,Sanhe,Hebei 650201,China;Earthquake Agencyof Inner Mongolia Autonomous Region,Hohhot,Inner Mongolia 010010,China)

机构地区：[1]防灾科技学院,三河650201 [2]河北省地震动力学重点实验室,三河650201 [3]内蒙古自治区地震局,呼和浩特010010

出　　处：《地震地质》2023年第1期92-110,共19页Seismology and Geology

基　　金：第1次全国自然灾害风险普查项目(地震灾害)全国1︰100万地震构造图编制(西藏区域)分项资助。

摘　　要：西藏地区地壳活动强烈,活动断层发育,存在很大的地震灾害风险,因此查清活动断层的分布是一项重要工作。遥感解译是查明活动断层最有效的手段,其核心技术是正确把握活动断层的典型遥感影像特征。文中结合1︰100万全国地震构造图(西藏区)编制工作,利用高分辨率卫星遥感影像对西藏地区改则幅(I45)全新世活动断层的典型遥感影像特征进行了研究,确定了区内全新世活动断裂玛尔盖茶卡断裂、日干配错断裂、依布茶卡地堑、青蛙湖断裂、东查断裂、其香错断裂中段的空间展布。结合前人的研究成果及区域对比分析,讨论了区内全新世断裂的最新活动时代、活动性质和活动强度,以及区内活动断裂的整体构造运动特征和发震能力。研究区北部的玛尔盖茶卡断裂和南部的日干配错断裂、其香错断裂为较大规模的NEE向左旋走滑断裂,具备发生约7.5级地震的能力。中部还发育了NEE向依布茶卡地堑、青蛙湖断裂和NW向东查断裂这3条规模相对较小的全新世断层,具备发生约7级地震的能力。上述断裂反映了该区受到SN向挤压,形成“V”字形共轭系统,总体运动特征表现为块体向E挤出的动力环境。Active faults refer to faults that have been active since the late Quaternary(100000~120000years)which are the culprits of large earthquakes.They can be divided into Holocene faults and Late Pleistocene faults.The Holocene fault is the active fault that has displaced on or near the surface in the past 10000 years.The Active faults may cause seismic surface dislocation in the future,which will damage the project crossing the active fault.It is necessary to take measures to avoid or resist the fault.Therefore,finding out the distributions of active faults are the prerequisite for reducing earthquake disaster losses and disaster risks.We undertook the compilation of the 1︰1000000 seismotectonic map of Tibet in the first national comprehensive risk survey of natural disasters.The preparation of a seismotectonic map is to conduct detailed investigation and research on active faults within the research scope,including large-scale active faults with a strong earthquake-generating capacity,as well as small-scale and highly active faults.The Qinghai-Tibetan plateau is a typical strong earthquake-prone area with wide distribution,high frequency,high intensity and shallow source of seismicity.This study introduces the Holocene active faults in the modified scale(I45)of 1︰1000000 international standard topographic map.We use Satellite remote sensing images to determine the locations of the faults,identify their characteristics,and assess the ages of their latest activity and quantitative parameters such as intensity.Satellite remote sensing interpretation is the most important method to study active faults.This is especially true in the Qinghai-Tibetan plateau region,where active fault traces are clear and lack overlying Quaternary layers.High-resolution satellite remote sensing images can capture various tectonic and geomorphological phenomena formed by fault activity.In the study area,we interpreted Six Holocene active faults by using high-resolution satellite images,including the MargaiCaka fault,the Riganpeicuo fault

关 键 词：西藏地区 全新世断层 典型遥感影像 羌塘地块 “V”字形共轭断裂系 

分 类 号：P315.2[天文地球—地震学]