地磁低点位移现象及其与地震的关系

本文用中国地磁台网多年的资料,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。低点位移是一种复杂的地球物理现象,受多种因素影响,其机制仍处在探索阶段。 

GEOMAGNETIC LOW-POINT DISPLACEMENT PHENOMENA AND THEIR RELATION TO EARTHQUAKES

On the basis of data recorded for many years by the network of geomagnetic observatories in China, the anomalous features of appearance time of the minima of diurnal variations (i.e. low-point time) of the geomagnetic vertical component and the variation of their spatial distribution (i e. phenomena of low-point displacement) have been studied. Such rare phenomena of geomagnetic anomalies are an objective reality, being well-correlated with the occurrence of earthquakes. It has been found that most earthquakes occur in the vicinity of the boundary line of sudden change of the low-point displacement and generally within four days before or after the 27th or 41st day counting from the day of appearance of the anomaly.The low-point displacement is one of the complicated geophysical phenomena which is affected by many factors and its mechanism is still under study.