GPS揭示的现今地壳运动与地震前兆特征  

CHARACTERISTICS OF CURRENT CRUST MOVEMENT AND SEISMIC PRECURSORS REVEALED BY GPS SURVEY

作　　者：吴云[1] 孙建中[2] 乔学军[1] 王辉[3] 张燕[1] 施顺英[1] 

机构地区：[1]中国地震局地震研究所,武汉430071 [2]中国地震局中国地壳运动观测网络工程中心,北京100036 [3]中国地震局分析预报中心,北京100036

出　　处：《大地测量与地球动力学》2003年第3期14-20,共7页Journal of Geodesy and Geodynamics

基　　金：国家自然科学基金 (4 0 0 740 2 4)课题 ;"十五"科技攻关计划 2 0 0 1BA60 1B0 2 -0 3 -0 7课题 ;国家重大科学工程"中国地壳运动观测网络"项目

摘　　要：利用“中国地壳运动观测网络”产出的GPS观测资料 ,采用球坐标系下非连续变形算法对资料进行计算 ,以此为基础 ,对我国大陆地块及其边界带运动与形变进行了分析。对GPS基准站的连续观测序列采用小波变换进行分解变换 ,分析了部分震例 ,探讨了从GPS连续观测序列提取地震前兆的方法。初步取得两点认识 :(1) 7级以上的大地震主要发生在走滑运动量大的活动边界 ,且与高应变率地块有关 ,这可以作为地震中长期预测判据 ;(2 )GPS基准站连续观测序列中的低频段 ,地震前 6个月或稍长时段有一定的前兆异常出现 ,这可以作为地震中短期预测判据。In accordance with GPS data produced from 'Crust Movement Observation Network of China'(CMONOC), we have computed and analyzed the current motion and deformation of the blocks and their boundaries in the continent of China using 'inverse DDA of a block system in the sphere coordinate', made wavelet transformation for the GPS observational sequences at continuously tracing stations and on the basis of analysis of some earthquakes investigated some approaches for abstracting precursory information from the GPS sequences. As a result we have the following recognitions. 1)The earthquakes with magnitude of 7 or over mainly occur on the active boundaries with large striking slip and they are related to the blocks with high strain rates.This would be index of high seismic risk region at long-and-middle time scale. 2) In the continuously observational sequences of GPS, there is some obviously precursory information with low frequencies occurred 6 months or longer before earthquakes, that would be index for the middle-and-short term earthquake prediction.

关 键 词：地壳运动 地震前兆 GPS 地震预测 

分 类 号：P315.725[天文地球—地震学] P228.4[天文地球—固体地球物理学]