昆仑山8.1级地震对川滇地区地壳水平形变的影响  

The Effect of Kunlun Mountains M_S8.1 Earthquake to Curstal Horizontal Deformation in the Sichuan and Yunnan Areas

作　　者：杨国华[1] 江在森[2] 张风霜[1] 刘峡[1] 韩月萍[1] 沈午春[1] 王利[1] 

机构地区：[1]中国地震局第一地形变监测中心 [2]中国地震局地震预测研究所,北京100036

出　　处：《中国地震》2007年第1期56-64,共9页Earthquake Research in China

基　　金：地震科学联合基金课题(A07066);国家科技支撑"强震监测预报技术研究"项目

摘　　要：为了从整体上（较大尺度）跟踪区域应变场的时空变化，并更客观地描述区域运动场，文中在区域无旋转的基础上使用了以提取中低频应变信息为主的连续非线性应变模型。根据《中国地壳运动观测网络》位于川滇地区GPS测站所产生的复测资料（1999年～2001年～2004年），以1999年～2001年的运动为基本参考（阶段性形变背景），从2001年和2004年两期资料中分离出了2001年昆仑山8．1级地震对其产生的主要影响量。结果表明：①昆仑山8．1级地震对JII滇地区产生了可识别的影响，且形变的方式与形变背景既有一定的相似性又有一定差异；②震前运动场非常有序；震后的位移场有序与杂乱并存，GPS测站的位移量一般为数毫米；③震前的主应变场基本为近东西向显张性、南北向显压性，且以张性为优势；震后四川地区基本上为东西向压、南北向张，且以压性为优势，云南地区北东向张、北西向压，且以张性为优势；④震前面应变以膨胀为主，收缩区基本位于川滇块体的东界及附近地区；震后四川地区为面收缩地区（越往北越大），南部为面膨胀地区。从整体上看，昆仑山8．1级地震对川慎地区能量的积累有积极作用，重点应注意西昌一东川段及附近地区。In order to track the space-time variation of region strain field on the whole （in large scale）, and describe the region movement field more objective, on the basis of region with no rotation, the paper uses. nonlinear continuous strain model focused on extracting medium-low frequency strain information. By use of the remeasured GPS data（ 1999 - 2001 - 2004） come from GPS monitoring stations in the Sichuan and Yunnan Areas in the Project of ＂ China Crust Movement Measuring Network＂, and in basic reference to movement of 1999 - 2001 （stage deformation setting）, we separate the main influencing fact of Kunlun Mountains Ms8.1 earthquake in 2001 from the data of 2001 and 2004, the result suggests： Firstly, the Kunlun Mountains Ms8.1 earthquake produce discriminating effect to the Sichuan and Yunnan Areas, at the same time, the deformation mode and setting have not only certain similitude but also some diversity; Secondly, the movement field before earthquake is very ordinal, but the displacement field after earthquake is ordinal as well as unorderly; The displacement amounts of GPS monitoring stations don＇t go beyond 10mm generally ; Thirdly, the main strain field before earthquake is basically extensive in the approximate EW direction and compressive in a SN direction, and the extension is predominant ; the main strain field after earthquake is compressive in a EW direction and extensive in a SN direction in the Sichuan area, and the compression is predominant, in the Yunnan area, it is extensive in a NE direction and compressive in a NW direction, and the extension is predominant; Fourthly, the surface strain before earthquake is dominated by superficial expansion, contractive area located basically in east boundary of the Sichuan and Yunnan block and its neighborhood;after the earthquake, the Sichuan area is surface contractive （the inore north, the more great）, the south of Sichuan is dominated by superficial expansion. General speaking, the happence of Kunlun Mountains Ms8.1 earthquake ac

关 键 词：昆仑山8.1级地震 川滇地区 GPS水平运动与应变 地震危险性 

分 类 号：P315[天文地球—地震学]