唐山地区铅垂线变化与地震前后地下物质变化的关系  

Relation between plumb line variation in Tangshan region and underground material change before and after earthquakes

作　　者：李正心[1,2] 李辉[3] 

机构地区：[1]中国科学院上海天文台,中国上海200030 [2]中国科学院测量与地球物理研究所,中国武汉430077 [3]中国地震局地震研究所,中国武汉430071

出　　处：《地震学报》2011年第6期817-827,844,共11页Acta Seismologica Sinica

基　　金：国家自然科学基金项目(10973031)资助

摘　　要：利用中国北京—唐山重力网1987—1998年46期重复测量的资料,计算了唐山地区间隔0.1°×0.1°各点的铅垂线变化.讨论了地下物质变化与地面一点铅垂线变化的关系,以及根据一个区域的铅垂线变化对地下物质变化进行研究的理论和方法;并以唐山地区1988年8月3日mb4.3地震和1995年10月5日mb5.0地震为例,对地震前后地下物质的变化进行了计算,给出了地下扰动体质心的地理位置和深度,以及扰动体本身的质量.证明了该地区伴随地震孕育、发生而产生重力变化和铅垂线变化的现象源自地下物质的变化.依据区域铅垂线变化的测量资料,可以研究地下物质的变化,因而可望为地球科学研究,其中包括地震预测的研究,提供一些前所未有的新信息.Plumb line variations（PLV） at the points with spacing of 0.1°×0.1°in Tangshan region during 1987—1998 are determined by using 46 batch repeated gravity observations of the Beijing--Tangshan network.Relation between underground material change（UMC） and PLV on ground are discussed and an approach of studying the UMC from regional PLV observation is developed.The UMC before and after two earthquakes（3 Aug.1988,mb4.3;5 Oct.1995,mb5.0） in Tangshan region,as examples,is studied,giving the location and depth of the mass center of underground disturbed body,as well as the mass quantity.It has been demonstrated that the obtained UMC is responsible for the PLV,as well as the gravity changes in the area,where an earthquake may be preparing and is going to occur.It is also possible to study the UMC from the PLV result deduced from the repeated gravity observations in an area.UMC determination is expected to provide new message in earth science study,including earthquake prediction research.

关 键 词：华北重力网 铅垂线变化 地下物质变化 地震 天体测量学 大地测量学 

分 类 号：P128.1[天文地球—天体测量]