地震前地磁垂直分量变化特征及其成因的讨论

A PRESEISMIC DECREASE VARIATION OF THE GEOMAGNETIC VERTICAL COMPONENT AHE TND DISCUSSION ABOUT ITS CAUSE

摘要:

本文分析了1976年7月28日唐山7.8级地震和1982年4月14日海原5.5级地震前的地磁变化。指出地震前地磁垂直分量减小的变化可能是高电导带附近的地震地磁前兆的一种特征。同时认为,这种地磁变化的原因可能是由于地幔物质对流导致居里等温面的变化所引起的。

Abstract:

In this paper, the geomagnetic variations on the earthquake of magnitude Ms7.8 occurred near Tangshan on July 28, 1976, and the earthquake of magnitude Ms5.5 occurred near Haiyuan were analysed. Then it is pointed out that the preseismic decrease variation of the geomagnetic vertical component may be a characteristic of the seismomagnetic warning sign of the earthquake occurred near the high electrical conductivity area. Meanwhile it is suggested that this geomagnetic variation may be caused by the change of the Curies constant temperature surface caused by the underground medium convection.