从德令哈地震分析青藏高原北缘东段的深部构造活动  

Analysis of deep tectonic activity in the eastern segment of the northern margin of the Qinghai-Tibetan Plateau based on the Delingha earthquake

作　　者：姜枚[1] 许志琴[1] 钱荣毅[2] 王亚军[1] 张立树[1] 

机构地区：[1]中国地质科学院地质研究所 [2]中国地质大学地球物理与信息技术学院,北京100083

出　　处：《中国地质》2006年第2期268-274,共7页Geology in China

基　　金：国土资源部及中国地质调查局青藏专项(2001010201;2001010203)资助

摘　　要：在祁连山南北布设的10台REFTEK宽频地震仪器记录到了2003年4月发生在仪器台阵范围内的6．7级地震及其数十次余震,提供了研究青藏高原北缘深部构造的新资料,对3级以上震源的定位和震源机制研究结果表明,柴达木盆地北缘逆冲左行走滑断裂东段的宗务隆山逆冲断裂在南北挤压作用下引发了此次地震活动,是陆陆碰撞和内陆俯冲的结果,青藏高原北缘的走滑断裂在浅部呈缓倾斜,深部往往以较陡的产状向下延伸。震源区的构造分析证实了印度板块岩石圈的超深俯冲作用对高原北缘的影响,受南北向应力作用影响形成的走滑断裂近东西向的位移目前仍很剧烈。An earthquake of magnitude 6.7 and dozens of aftershocks were recorded by ten REFTEK broad-band seismographs in the range of the array of seismograph stations deployed north and south of the Qilian Mountains in April 2003. These records provide new data for the study of the deep structures on the northern Qinghai- Tibetan Plateau. The focus location and focal mechanism study of the shocks of magnitudes 〉3 show that those earthquakes were initiated by the Jun U1 Mountain thrust fault in the eastern segment of the northern Qaidam basin sinistral strike-slip fault under north-east compression and are the result of continent-continent collision and intracontinental subduction.The strike-slip fault on the northern margin of the Qinghai-Tibet Plateau dips gently in the shallow levels of the earth＇s crust, while in the deep levels it usually dips steeply toward the interior. The structure analysis of the hypocenter area verified the influence of the super-deep subduction of the Indian lithospheric plate on the northern margin of the plateau. The nearly east-west displacement of the strike-slip fault formed by the action of north-south stress is still very intense at present.

关 键 词：德令哈 青藏高原北缘 地震 精确定位 活动断裂 

分 类 号：P315.2[天文地球—地震学]