地表与井下地电阻率观测数据分析

Assessment of Ground and Borehole Resistivity Data Observed from the Same Site

本文介绍了目前中国运行时间超过2年以上的4个同场地地表和井下地电阻率观测台站的基本情况,通过分析观测曲线动态变化、观测精度以及映震能力,得到以下初步结果:1井下地电阻率观测对风、降雨以及杂散电流干扰的抑制能力要优于地表观测;2井下地电阻率观测年变化与地表有较大的差别,且井下观测大大削弱了年变化幅度;3井下垂直方向地电阻率观测数据相对水平方向来说阶跃及突跳较频繁;4天水、河源、海安台井下观测对其附近地震有一定的映震能力。

This paper presents observational data of the 4 stations of surface and deep-well equipments which running time over 2 years at the same site and the same time period.By analyzing dynamic change of curves,observation accuracy and earthquake reflecting ability of the observed data,we concluded that ① Deep borehole resistivity observation better restrain interferences of winding,raining and stray currents ground observation; ② Annual variation amplitude of deep-well is different from surface resistivity observations and can greatly weaken the amplitude of annual variation; ③ Deep-well vertical observation data shows more frequently step offsets and sudden jumps relative to horizontal observation data; （4） Deep-well observation of Tianshui,Heyuan and Haian stations have good reflecting ability to earthquake nearby.