摘要
在构造磁效应的实验观测中,笔者发现,山洞内测点与地面测点的地磁场总强度日变化存在差异现象。山洞内测点比地面测点的地磁场总强度日变化的幅度小,它们之间日变幅度的差值δf具有随其日变幅度ΔF增加而增加的趋势。实验观测结果表明,北京台地面测点与其山洞内测点的δf=0.45nT,δf/ΔF=0.013;滇西地区下关地面测点与洱源山洞内测点的δf=2.4nT,δf/ΔF=0.042。这两次实验结果的差异可能反映了它们地下介质的电磁性质有所不同。鉴于我国有些地方的地磁观测是在山洞内进行的,在利用这些资料从事地磁分析与震磁前兆探索研究时,应当考虑山洞所带来的影响,以便获得可靠的结果。
During the experimental observation of tectonomagnetic effects the discrepancy between daily variations of geomagnetic total intensity inside cave and at surface has been found out. The daily variation amplitudes inside cave are smaller than that at surface. The discrepancy of of daily variation amplitudes between those two sites shows an increasing tendency with the increment of daily variation amplitude ΔF. The result from experimental observations suggests that the meandescrepant value δf=0.45nT and δfΔF=0.013 between those two sites inBeijing Station, and δf=2.4 nT and δfΔF=0.042 between Xiaguan surface site and Eryuan cave site in Western Yunnan area. The difference of the two experimental results reflects the different electromagnetic properties of their underground medium. The geomagnetic observations are operated inside cave in some places in China, it is necessary to consider the effect due to the cave itself in geomagnetic analysis and seismomagnctic precursor research by using those data, so as to obtain reliable results.
出处
《地震研究》
CSCD
北大核心
1990年第3期265-272,共8页
Journal of Seismological Research
基金
国家地震局与地震科学联合基金会的支持和资助
关键词
地磁
观测
日变差现象
地磁场
Geomagnetic total intensity, Discrepancy in daily variation, Tectonomagnetic experiment, Site inside cave, Western Yunnan, Beijing Station
