强震前重力场等位面二次偏微商异常变化分析  

ANALYSIS OF THE ANOMALOUS CHANGE OF QUADRATIC PARTIAL DERIVATIVE OF GRAVITY EQUI-POTENTIAL SURFACE PRIOR TO STRONG EARTHQUAKES

作　　者：郑洪[1] 张洪魁[1] 李国江[1] 柴景昆[1] 商建民[1] 

机构地区：[1]北京市地震局,北京100080

出　　处：《大地测量与地球动力学》2002年第1期46-50,共5页Journal of Geodesy and Geodynamics

基　　金：北京市自然科学基金 (8992 0 0 8)资助项目

摘　　要：采用相关分析方法对北京平谷台 1971～ 1977年获得的重力位 2次偏微商曲率值 K进行处理 ,消除降雨等噪声对观测值的影响 ,得到较真实的重力等位面弯曲变化值 KS。分析研究的结果表明 ,1975年 2月 4日海城 7.3级地震、1976年 7月 2 8日唐山 7.8级地震、1976年 11月 15日宁河 6 .9级地震、1977年 5月 12日宁河 6 .5级地震前 ,曲率值 KS均有明显的震前异常出现。在此基础上进行定量分析处理 ,求得各次地震前 KS值的真正异常变化量△ KS,并运用近似积分法求得异常面积与地震震级之间的关系 ,初步建立了预报方程 。A correlation analysis method was used to process the quadratic partial derivative curvature vector of gravity potential (\%K\%) obtained at Pinggu station from 1970 to 1977, so as to remove the influence of the noises from rainfall and the like, and get vector \%K\-s\% which represents the true value of the bending degree of equi potential surface of gravity. Analysis of \%K\-s\% shows that obvious anomalies appeared prior to the Haicheng earthquake of \%M\%s7.3 on Feb. 4, 1975, the Tangshan earthquake of \%M\%s7.8 on Jul. 28, 1976, the Ninghe earthquake of \%M\%s6.9 on Nov. 15, and the Ninghe earthquake of \%M\%s6.5 on May 12, 1977. We use a parameter \%△K\-s\% to quantitatively describe the anomalous change of \%K\-s\% prior to earthquakes, and then a prediction equation was established by studying the statistic relationship between the time integration of \%△K\-s\% and the magnitude of earthquakes, and this way supply a reference prediction method for the estimation of the magnitude of coming earthquakes with different epicentral distance by using gravity data from a single station.

关 键 词：重力场等位面 二次偏微商 降雨干扰 回归分析 地震前兆 曲率矢量值 

分 类 号：P315.72[天文地球—地震学]