回归分析在震磁关系研究中的应用

通过相关分析北京、兰州、银川、红山地磁台地磁垂直分量Z(世界时13—14时)时均值资料(每两台相组合,以月为统计单位),得相关系数R和回归系数b。经统计检验,发现不同台站的R、b大小虽有差异,但正常情况下均在其置信区间变化(置信概率0.95)。几次中强震前,b、R大幅度下降,连续偏离其控制区间,至临震前1—2月或当月趋于恢复或完全恢复。对不同台组的垂直分量差ΔZ与时间作回归分析(ΔZ为时间t的函数),得不同台站的线性回归方程及相关系数R。正常情况下ΔZ在回归方程的置信区间变化(置信概率0.95),当地磁台附近孕育中强以上地震时,ΔZ明显偏离回归方程的控制区间。应用以上两种方法对80年代以来宁夏及其邻区的六次中强地震作了对应效果检验,并对发现的问题作了简略探讨。

THE APPLICATION OF REGRESSION ANALYSIS STUDY OF RELATIONSHIP BETWEEN EARTHQUAKE AND MAGNETISM

Through correlation analysis of the mean value of vertical geomagnetic component Z observed at each hour at Beijing, Lanzhou, Yinchuan, Hongshan geomagnetic stations, the correlation coefficient R and regression coefficient b were obtained. It was found by statistical test that R , b from different stations were different, but varied in confidence interval under normal condition (confidence probability is 0. 95). Before several medium and strong earthquakes, R and b value declined greatly, deviated continuously from control range, then, they returned gradually to mormal value in 1 or 2 months before the quakes. Through regression analysis of the vertical component difference AZ of different station group and time AZ is the function of time t ) ,the equation of linear regression and correlation coefficient R were obtained. Under normal condition, varied in confidence interval of the linear regression equation (confidence probability is 0. 95). When medium and strong earthquake was developing around geomagnetic station, AZ deviated obviously from the control time of the regression equation. Two methods mentioned above were used to test the corresponding effect of 6 strong earthquakes thar had occurred in Ningxia and its adjacent area since 1980s,and some problems were discussed briefly.