基于地壳介质各向异性分析江苏及邻区构造应力特征  

Tectonic stress analysis based on the crustal seismic anisotropy in Jiangsu and its adjacent area

作　　者：吴晶[1,2] 高原[3] 石玉涛[3] 赵霞[2] 李金良[2] 

机构地区：[1]中国科学院地质与地球物理研究所,北京100029 [2]江苏省地震局,南京210014 [3]中国地震局地震预测研究所,北京100036

出　　处：《地球物理学报》2010年第7期1622-1630,共9页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(40804012);江苏省自然科学基金项目(BK2008485);地震行业科研专项(200808068)联合资助

摘　　要：江苏及邻区(116°E～123°E,30°N～36°N)跨中国大陆3个地质构造单元(华北地台、扬子地台、华南褶皱系),本文采用江苏区域数字地震台网(1999～2008年)共10年的观测资料,使用地壳介质剪切波分裂系统分析方法(SAM),获取研究区域内共11个台站的剪切波分裂参数.研究结果表明,江苏及邻区背景应力环境并非来自单一的某个一级构造单元,而是受到3个地质构造单元的共同约束.研究区域西南部的应力环境主要受到板桥—南渡断裂、茅山东侧断裂、幕府山焦山断裂共同作用,具有局部构造应力特征.研究区域东南部应力环境空间分布特征以长江为界,长江以北地区主压应力场方向为NW方向,而长江以南地区的主压应力场方向为近E-W方向.据此推断,长江以南可能存在近E-W方向的活动构造,长江可能是两个具有不同应力特征活动构造的边界.Jiangsu and its adjacent area （116°E～123°E,30°N～36°N） is located in the crossing part of three Chinese geological blocks （North China Craton, Yangtze Craton, South China Folds）. In the paper, the data from Jiangsu Seismological Network （199942008） are analyzed with the seismic anisotropy analysis method in crust （SAM）. The shear-wave splitting parameters from 11 stations are obtained. It is shown that the stress field of the whole area is not controlled only by a certain Chinese block, but by three. In the southwest research area, it is regarded that the three faults （Banqiao-Nandu fault, East Maoshan Fault and Mufushan-JiaoshanFault） are influential on the stress field, which shows a local tectonic structure. In the southeast area, it is found that Yangtze River plays an important role in the division of crust tectonic structure. In the North of Yangtze River, the principal stress is in NW direction, while in the South of Yangtze River, it is in nearly E-W direction. Thus, there is probably an unknown active structure in nearly E-W direction in the South of Yangtze River, and Yangtze River is the border of two different tectonic structures.

关 键 词：江苏 地震各向异性 剪切波分裂 偏振方向 应力 

分 类 号：P315[天文地球—地震学]