葛洲坝-南桥直流输电线路对地磁台的影响

从20世纪80年代后期开始，佘山地震台的垂直分量Z受到类似突跳的电磁干扰，最大可达十几个nT，干扰持续时间没有规律，少则几小时，多则几天，经查，干扰来自葛洲坝-南桥直流输电系统，且影响范围广泛，佘山地震台只是其中一个台站。因此，有必要对此进行研究，弄清其干扰机制，探讨采用计算的方法以确定其干扰幅值的可能性。

The influence of Gezhouba-Nanqiao's direct current transmission line to geomagnetic observatory

Since tbe late 1980s of last century, the observation of vertical component Z in Sheshan Seismic Station has been suffered the electromagnetic interference of kick types, its magnitude may be several nT. The duration of interference can be as long as several days, or short as few hours, following no rule. It is confirmed after looking over that the disturbance comes from the direct current power transmission system from Gezhouba to Nanqiao. The affected area is large and the Sheshan Seismic Station only one of the affected. It is necessary to understand the mechanism of the interference and determinate the magnitude of disturbance theoretically. We like to open the discussion to every interesting body.