玉树7.1级地震余震重新定位及其时空分布特征研究  

RELOCATION OF AFTERSHOCKS OF YUSHU Ms7.1 EARTHQUAKE AND THEIR SPATIAL DISTRIBUTION CHARACTERISTICS

作　　者：刘巧霞[1] 沙成宁[2] 杨卓欣[1] 段永红[1] 

机构地区：[1]中国地震局地球物理勘探中心,郑州450002 [2]青海省地震局,青海810001

出　　处：《大地测量与地球动力学》2012年第4期5-9,14,共6页Journal of Geodesy and Geodynamics

基　　金：国家自然科学基金(41040002);地震科技星火计划青年基金项目(XH12067Y);中国地震局地球物理勘探中心科技论著201101

摘　　要：采用双差地震定位法对2010-04-14—12-31日发生的玉树地震余震进行了重新定位。结果表明:余震分布区随时间发生转移,与应力增长区变化有关。余震分布呈现空间非均匀性,隆宝两侧的余震在密集程度、分布带宽度以及震源深度上均存在差异。玉树地震余震主要发震构造为倾向北东、倾角近乎直立的甘孜-玉树断裂带北支。隆宝西北的高密度余震群不仅与玉树-隆宝断裂有关,更主要是与近垂直于玉树-隆宝断裂的北东向"软弱面"有关。A part of the aftershocks of Yushu earthquake occurred from April 14 to December 31,2010,were relocated by means of the double difference algorithm.These following conclusions can be obtained from the results.The area changing of stress growth led to aftershocks distribution shifting over time.The aftershock distribution presents spatial inhomogeneity.On both sides of Longbao,the intensity,width and the focal depth of the aftershocks are different.The seismogenic fault of aftershocks of Yushu earthquakes is the northern branch of Garzê-Yushu fault zone,i.e.Yushu-Longbao fault,which dips to northeast with high-angle left-lateral strike-slip.To the northwest of Longbao town,the intensively distributed aftershock group is not only due to Yushu-Longbao fault zone,the more important seismogenesis is that the northwest ＂weak plane＂ is nearly vertical to the fault.

关 键 词：玉树MS7.1地震 重新定位 双差地震定位法 余震分布 发震构造 

分 类 号：P315.63[天文地球—地震学]