用GPS时间序列获取中国大陆微动态应变场  

EVALUATION OF MICRO-BEHAVIOR OF STRAIN FIELD IN CHINESE MAINLAND WITH THE GPS TIME SERIES

作　　者：敬少群 王佳卫 吴云[2] 周硕愚[2] 施顺英[2] 

机构地区：[1]湖南省地震局,中国长沙410001 [2]中国地震局地震研究所,中国武汉430071

出　　处：《地震学报》2006年第5期478-484,共7页Acta Seismologica Sinica

基　　金：国家自然科学基金项目(40074024)资助.

摘　　要：基于中国大陆GPS观测在国际地球参考框架（ITRF）获得的站点位置，由三角形法通过反演逐年推算中国大陆年微动态应变场．结果显示，研究区年微动态应变场大致以南北地震带为界．西部地区存在方向大体一致的年主压应变优势分布方向，方向自西向东、由近南北向转为北东向，与近代应变场的方向一致，表明西部地区变形主要是由印度板块向北推进和西伯利亚地块相对南推形成的，且整体上仍是新构造运动的继承；东部大部分地区不存在年主应变的优势分布方向．年最大剪应变在不同地区差别很大，变化范围从4．13×10^-8～7．0×10^-10，总体上西部大于东部．同一区域年最大剪应变的多年变化表明，西部变化大，东部变化平缓．年面膨胀显示，研究区大部分为压缩区，且同一区域的多年变化平缓．Based on the time series of GPS station coordinate in the international earth reference frame, we evaluate annual micro-behavior of strain field in Chinese mainland with the triangle method. The results show that the annual micro-behavior of strain field is divided into two parts by the north-south earthquake belt in the research region. The prevailing direction of the compressive principal strain field is nearly consistent in the western region. From west to east, the direction varies from NS to NE. It is in accordance with the direction of the modern compressive principal strain field. This suggests that geologic deformation in western region was mainly caused by that India tectonic plate pushes the research region northward and the Siberia plate pushes it southward relatively. It is an inheritance of new tectonic motion. The prevailing direction of the principal compressive strain field does not exist in the eastern region. The annual biggest shear strain is different greatly in every grid-cell. The values varies from 4.13× 10^- 8 to 7.0× 10^- 10. By and large the annual biggest shear strain in the western region is bigger than that in the eastern region. And so is the variation between any two consecutive annual biggest shear strains in the same grid-cell. The annual surface dilatation show that in most grid-cells of the research region the surface dilatation is in compressibility, and the variation between any two consecutive annual surface dilatation in the same grid-cell is small.

关 键 词：GPS时间序列 微动态应变场 年应变场 

分 类 号：P315.727[天文地球—地震学]