云南省的地磁短周期变化异常

云南省处于我国南北地震带的南端.该省新构造运动剧烈,地震活动频繁.同时,这里与西藏高原接壤,地下构造颇为复杂.因此,我们收集了该省的地磁短周期变化资料,并进行了初步分析.所得结果表明,云南省地磁短周期变化存在着异常.其表现为:西北自丽江向东南经下关、楚雄到通海,有一条西北-东南的分界线.此线的东北与西南,地磁湾扰、磁暴急始等短周期事件垂直分量的变化△z 呈现反号.由此推断,在该省地下存在着自西北到东南走向的电导率异常带.最后,简单讨论了与高导带存在有关的其他地球物理现象. 

SHORT-PERIOD GEOMAGNETIC VARIATION ANOMALY IN YUNNAN PROVINCE

Yunnan Province is situated at the southern end of the North-South Seismic Belt of China. This area bounded on the west by the Xizang Plateau, with very intense recent tectonic movements and high seismic activity, consists of very complicated crustal structures.Geomagnetic data observed at nine stations in Yunnan Province were collected and preliminarily analysed. Results obtained show that short-period geomagnetic variation anomaly does exist. There is a northwest-southeast demarcation line, starting from li Jiang on the northwest, southeastward to XiaGuan, ChuXong and Tong Hai of the province. △Z (Changes in the Vertical field) for the sudden storm commencements and geomagnetic bays to the northeast and southwest of this line appear opposite in signs. It is therefore inferred that a northwest-southeast belt of high conductivity exists underneath Yunnan Province.Finally, other geophysical phenomena related to this high conductivity belt were discussed briefly.