地磁“低点位移”预报地震方法的研究

RESEARCH ON EARTHQUAKE PREDICTION METHOD OF GEOMAGNETIC LOW-POINT DISPLACEMENT AND ITS MECHANISM

本文用中国地磁台网20多年的资料研究了地磁垂直分量日变极小值出现的时间(低点时间)在空间分布的异常特征,即“低点位移”现象。这种少见的地磁异常现象是客观存在的。与地震的发生有较好的相关性。其发震日期为异常日以后的第27天或41天前后4天,发震地区在低点位移突变分界线附近。 此方法预报6级以上地震有一定效果。预报发震时间较好,但预报地区范围较大,有一定的虚报和漏报。

This paper studies the anomalous features of the appearance time of minimum diurnal variation of geomagnetic vertical component (low-point time) in spatial distribution (name.lv phenomenon of low-point displacement) using the data recorded by the Chinese network of geomagnetic stations for more than 20 years. Such rare phenomenon of geomagnetic anomalies is objective reality which is well-correlated to the occurrence of earthquakes. The causative date is four days around the 27th day or 41st day after the abnormal date and the causative area is in the vicinity of the boundary line of the sudden change of the low-point displacement. It is better for this method to be used to predict the occurrence time, but there are certain false alarm and failure in prediction when the range of predicted area is large.