玉树7.1级地震断裂特征与地震地表破裂带  

CHARACTERISTICS OF M_s7. 1 YUSHU EARTHQUAKE FAULT AND THE SURFACE RUPTURE

作　　者：陈正位[1,2] 杨攀新[1,2] 李智敏[3] 李家辑 

机构地区：[1]中国地震局地质研究所,北京100029 [2]中国地震局预测研究所,北京100036 [3]青海省地震局,西宁810000 [4]西藏自治区地震局,拉萨850000

出　　处：《第四纪研究》2010年第3期628-631,共4页Quaternary Sciences

基　　金：地震行业科研专项项目(批准号:200808013);中国地震局地震预测研究所基本科研业务专项项目(批准号:02091412)资助

摘　　要：2010年4月14日07时49分在青海省玉树县发生了7.1级地震,震中位于33.2°N,96.6°E,自玉树县城至隆宝镇造成了大量房屋倒塌和人员伤亡。地震发生在NW向的玉树-甘孜断裂两段的玉树-治多断裂上,自隆宝镇东至玉树县城,地震引起了长约50km的地震地表破裂带,主要分布在第三纪红砂岩、高漫滩及河床中,致使公路错断、桥梁位错,并引发大量滑坡和崩滑。震中附近的调查表明,地表破裂带主要沿NW向的玉树-治多断裂展布,总体走向NW320°,分为两组,一组为NW向,另一组为NE向,NW向的破裂为左旋走滑,发育一系列小的类拉分盆地,NE向的破裂表现为正断性质。由震源机制解和断裂特征判定,NW向的玉树-治多断裂为此次地震的发震构造。The 2010 Yushu Earthquake that measured at Ms 7. 1 occurred at 7 ： 49 on April 14, 2010,in Yushu County, Qinghai Province. The epicenter is 33.2 °N,96. 6 °E. Thousands of houses collapsed from the Jiegu town to Longbao town in Yushu County. The earthquake occurred as the result of movement of the Yushu-Zhiduo fault which is NW segment of Yushu-Ganzi fault. From the location of micro-epicenter to Yushu County,surface rupture which length is about 50km distributes along Yushu-Zhiduo fault. The ruptures are also found in the Tertiary red sandstone, high floodplain and riverbed. Along the surface ruptures, roads and bridges were destroyed and dislocated, and a lot of landslides were trigged by the shock. According field work,a series of NW-trending and NE-trending surface ruptures distribute along the Yushu-Zhiduo fault zone. The NW-trending rupture is left strike-slip and more small pull-apart basins were developed. The NE-trending rupture is extension. The earthquake＇s epicenter and focal-mechanism are consistent with it having occurred as the result of movement on the Yushu-Zhiduo fault or a tectonieally related fault.

关 键 词：玉树地震 甘孜-玉树断裂 地表破裂带 发震构造 

分 类 号：P315.2[天文地球—地震学]