2008年于田M_S 7.3地震地表破裂带特征及其构造属性讨论  

SURFACE RUPTURE FEATURES OF THE 2008 YUTIAN M_S 7.3 EARTHQUAKE AND ITS TECTONIC NATURE

作　　者：徐锡伟[1] 谭锡斌[1] 吴国栋[2] 陈建波[2] 沈军[2] 方伟[2] 宋和平[2] 

机构地区：[1]中国地震局地质研究所,国家地震活断层研究中心,北京100029 [2]新疆维吾尔自治区地震局,乌鲁木齐830011

出　　处：《地震地质》2011年第2期462-471,共10页Seismology and Geology

基　　金：地震行业科研专项“新疆于田7.3级地震与阿什库勒火山综合科学考察”(201008004);科技部国际科技合作项目(2009DFA21280)共同资助

摘　　要：新疆于田MS7.3地震发生在西昆仑块体与昆仑-柴达木-祁连块体之间的阿尔金断裂西南端NE向张剪切段邻近区域,也是阿尔金断裂、康西瓦断裂和昆仑断裂带西端玛尔盖茶卡断裂等交会部位,对理解青藏高原的变形及其动力学演化过程具有十分重要的作用。高分辨率卫星影像解译和野外考察表明,于田地震在阿什库勒火山群南部玉龙喀什河源头近SN向雪山西麓断裂上形成了由不同走向、不同滑动性质的地表破裂组合而成的地震地表破裂带,整体呈NS—NNE向展布,全长约31km。在地表破裂带测量到的最大左旋走滑位移1.8m,最大垂直位移约2.0m,发震断层应归属到阿尔金断裂西南尾端的张性区构造,符合昆仑-柴达木-祁连块体与西昆仑块体向东滑移在其与西昆仑块体之间的张剪切边界力学性质,显示出昆仑-柴达木-祁连块体存在向东滑移的现象。High-resolution satellite image interpretation and field investigation indicate that the surface rupture zone produced by the Yutian MS7.3 earthquake is～25km long along a NS-trending fault at the western piedmont of a snow-covered range at the upper reach of the Yurungongkash River,about 20km south of the Ashikule Volcanoes.The surface rupture zone consists of different striking ruptures with both normal and left-lateral faulting components.The maximum left-lateral and vertical co-seismic slips measured in the field are～1.8m and～2.0m,respectively.Its seismogenic NS-trending fault belongs to the secondary structure at the NE-trending tensile area of the southwestern end of the Altyn Tagh Fault,which conforms to the eastward escape of the Kunlun-Qaidamu-Qilian block,relative to the Western Kunlun block.

关 键 词：于田MS7.3地震 地震地表破裂带 同震位移 康西瓦断裂 阿尔金断裂 

分 类 号：P315.2[天文地球—地震学]