井下地电阻率观测异常核实实例

Anomaly Confirmation in a Deep-well Geo-electrical Resistivity Observation

针对2015年12月17—19日甘肃省陇南市汉王台地电阻率井下观测三道同步出现的振荡变化,通过现场核实,并对观测数据进行对比分析后得到:此次垂向观测记录到的扰动变化不是来自深部地下介质的电性变化,而是浅部的干扰,可能因素是台站高压电扰动(或变压器漏电)与台站测区草坪浇水导致地表湿润易于传导有关;通过这次异常核实,对井下地电阻率观测有了较为完整的认识,为资料突变核实步骤和分析方法积累了一定经验,也为探讨深井地电阻率变化是否是地震前兆增添了佐证。

Vacillation changes occurred synchronously in three channels of the deep-well geo-electrical resistivity observation at the Hanwang station in the Chinese city of Longnan on December17,2015,and continued until December 24.The cause of these changes could not be determined,so we verified the anomaly on site.After a field survey and a comparative analysis of the observation data,we found that the disturbances were not from changes in the electrical properties of the deep underground medium,but from shallow interference.This could have been a disturbance in the high-voltage power through the station,or an enhanced conduction of the wetting surface caused by watering the grass in the observation area of the station.By identifying this anomaly,a comprehensive understanding of deep-well geo-electrical resistivity observation was acquired,and experience of the verification procedure and analysis method of data mutation was accumulated.