自然电场全方位观测试验与地表影响因素分析研究

Whole-directional Test Observation of Spontaneous Potential Field and Surface Influence Factors

自然电场是由地球介质物理、化学作用产生的天然电场,是地电场的重要组成部分。2016年至2017年期间,在四川省成都市地震局所属崇州地震台,开展了自然电场全方位观测试验。试验结果显示:(1)零输入电压同步观测结果满足最大允许误差的指标要求,同点位电极极化电位差观测结果基本满足长期稳定性指标要求,观测系统总体工作可靠;(2)同测向多个测道对比观测结果具有比较好的一致性和相关性,能够基本反映该试验测区自然电场的变化特性;(3)自然电场全方位观测结果在各个测向具有比较大的差异性,受地表复杂因素影响可能为主要原因。进一步研究显示,当存在地表水的水平或横向渗流时,由此形成的过滤电场作用对自然电场观测产生的附加影响比较大,特别是当地形地貌比较复杂时,其影响更为明显。

The spontaneous potential field, an important component of the geo-electric field, is a natural electric field, which is formed by the physical and chemical effects of the earth medium. From 2016 to 2017, an whole-directional observation test of the spontaneous potential field was carried out in the Chongzhou seismic station. The test results show that. ① the observation system is reliable, with the results of the zero input synchronous test meet the requirements of the maximum permissible error, and the results of the electrode potential test meet the basic requirements of the long-term stability; ② the results of experimental observation can basically reflect the changing characteristics of spontaneous potential field in the test area, with good consistency and relevance, which compared with the results of the multiple device in the same direction;③ the great difference was found in the results of the spontaneous potential field from the different directions, with the main reason as the complicated influence factors from the earth surface. The further study shows that, it has a great additional influence on the spontaneous potential field observation with the result of the filtering action, when the horizontal seepage of the surface water was existed, and it has particularly obvious with the complex topography especially.