依据GPS数据研究伽师及帕米尔东北侧1994～1998年地壳水平运动及其与强震群的关系  

RESEARCH ON HORIZONTAL CRUSTAL MOVEMENT FROM 1994 TO 1998 IN JIASHI AND THE NORTHEAST TO PAMIR & ITS RELATION TO STRONG EARTHQUAKE SWARM ON THE BASIS OF GPS DATA

作　　者：秦小军[1] 周硕愚[1] 赵齐乐[1] 乔学军[1] 王琪[1] 

机构地区：[1]中国地震局地震研究所,武汉430071

出　　处：《地壳形变与地震》2001年第4期1-7,共7页Crustal Deformation and Earthquake

基　　金：国家 973项目<大陆强震机理与预测>子课题 (G19980 40 70 3)资助

摘　　要：利用伽师强震群区及帕米尔东北侧地区 1994～ 1998年的GPS监测成果 ,用DDA方法模拟了伽师强震群前后该地区地壳运动和应力应变的变化过程。结果表明 :在此期间伽师地区的应变以南北向挤压为主 ,伽师附近最大主应变变化达到 5× 10 - 8/a ,最大剪应变变化也超过 2 .5×10 - 8/a ,明显高于周边地区。伽师强震群的发生与GPS监测成果反映的该地区地壳运动和应力应变的变化存在明显的对应关系。GPS监测成果反映出在伽师地区有一应力应变变化的集中区域。通过在伽师强震群震中分布块体中强行沿其最大剪应力方向 (NE)增加一新的破裂 ,可使该块体应力应变下降至与周围块体相均衡 ,且能量可能沿柯坪断裂向东北方向传递。新增断裂的运动呈左旋 。Using the GPS data in the region of Jiashi and the northeast to Pamir from 1994 to 1998, the crustal movement and stress strain rate before and after the strong earthquake swarm is simulated by DDA (Discontinuous Deformation Analysis) method. The results show that in that period the strain rate of Jiashi region indicates mainly compressional deformation along NS direction. The maximum main strain rate reaches 5×10 -8 /a and the maximum shear strain 2.5×10 -8 /a. It is obviously higher than that in the surrounding area and has corresponding relation with the Jiashi strong earthquake. The results of GPS survey also shows that there is a focus area in the Jiashi region. By adding a new fault to divide the Jiashi block where the strong earthquake distribute, the stress strain of the block is falls and makes the block balance with around blocks. The movement of the new adding fault shows left leteral and leads the block to right leteral slip.\;

关 键 词：伽师强震群 DDA方法 地壳运动 GPS监测 最大剪应力方向 

分 类 号：P315.725[天文地球—地震学]