青藏块体东北缘地壳水平应变场数值模拟研究  

Numerical simulation of the crustal horizontal strain field in Northeastern Margin of the Qinghai-Tibet Block

作　　者：瞿伟[1,2] 张勤[1,2] 王庆良[3] 凌晴[1,2] 管建安[1,2] 

机构地区：[1]长安大学地质工程与测绘学院,西安710054 [2]西部矿产资源与地质工程教育部重点实验室,西安710054 [3]中国地震局第二监测中心,西安710054

出　　处：《地球物理学进展》2010年第3期783-788,共6页Progress in Geophysics

基　　金：国家自然科学基金重点项目(40534021;1212010914015);国家自然科学基金项目(40672173;40902081);国家自然科学基金青年科学基金项目(40802075)联合资助

摘　　要：基于青藏块体东北缘1999～2001年GPS结果,分别采用块体整体旋转与线性应变模型和弹性力学有限元法这两类地壳形变数值模拟方法,分析了该区地壳水平应变场特征.结果表明:(1)两类方法在研究地壳形变时各具一定的优势,前者对块体整体运动变形及块体与块体之间的相关性研究具有一定的优势,而后者则较强体现出了应变高值区与深大断层在空间分布的紧密结合性;(2)两类方法所获得的应变高值区具有良好的空间分布一致性,主要集中在阿尔金断裂、祁连山断裂中东段、东昆仑断裂和海原断裂这些深大断裂处及其附近,面压缩值达到了-3×10^(-8)以上,最大剪应变值达到了10×10^(-8)以上;(3)应变高值区的空间分布与中强地震的发生具有一定的对应关系.Based on the GPS observations in the northeastern margin of Qinghai-Tibet from 1999 to 2001, two methods of simulating the crustal deformation（the overall rotation of the block with the linear strain model and finite element method） are applied to analyze the features of crustal horizontal strain in this area. The result shows that both the two methods have certain advantages in studying crustal deformation. The former is strong in the study of deformation of overall motion of blocks and correlations between blocks, while the latter shows huge superiorities in close associativity of spatial distribution between high-strain areas and faults that are big and deep. High-strain areas determined by the two methods have a better consistency in spatial distribution. They mainly are located at the big and deep faults and its vicinity, such as the Altin Tagh fault, the mid and east of Qilian fault, East Kunlun fault and Haiyuan fault, where the surface compressive strain reaches the value of -3 × 10-8, and the maximum shear strain reaches the value of 10× 10-8. Finally, it also shows some corresponding relations between seismic activity and highstrain areas.

关 键 词：青藏块体东北缘 整体旋转 线性应变 有限元 应变特征 中强地震 

分 类 号：P315[天文地球—地震学]