小极距井下地电阻率观测对地表环境影响的抑制分析——以北京地区台站为例  

Restraining Analysis of the Small Distance Borehole Apparent Resistivity on Surface Environment Influence based on Observational Stations in Beijing

作　　者：王同利[1] 邢海林 崔博闻[1] 王丽红[1] 孙小入 WANG Tong-li;XING Hai-lin;CUI Bo-wen;WANG Li-hong;SUN Xiao-ru(Beijing Earthquake Agency,Beijing 100080,China)

机构地区：[1]北京市地震局,北京100080

出　　处：《地震》2023年第2期1-13,共13页Earthquake

基　　金：中国地震局星火科技项目(XH21001);冬奥会保障晋冀蒙监测能力提升项目。

摘　　要：地震地电阻率是观测中强地震孕震过程中微变形或微破裂变化的方法之一。近年来发展起来的小极距井下地电阻率观测,不仅能够抑制地表环境干扰,还能够缓解地表地电阻率占地面积大的困扰。基于北京地区延庆台、平谷台和通州台小极距井下地电阻率观测,通过与同场地地表地电阻率对比观测和数值模拟计算,分析了地表铁质干扰、季节变化、降水和潜水等因素对地电阻率观测的影响。结果显示,与同场地地表地电阻率相比,小极距井下地电阻率对地表自然环境因素的影响有较好的抑制能力,增强了观测效能。Apparent resistivity is one of the methods to observe the micro-deformation or micro-fracture in the preparation process of middle and strong earthquakes.In recent years,the borehole apparent resistivity has been developed.It can restrain influence of environmental interference on surface apparent resistivity.Compared with the surface apparent resistivity,it can reduce influence of environmental interference and electrode devices layout area.In this paper,based on the observation of borehole apparent resistivity of small distance in Yanqing,Pinggu and Tongzhou stations in Beijing,the influence of surface irony interfrence,seasonal variation,precipitation,phreatic water and so on are analyzed.By compared with the surface apparent resistivity at the same location,the results show borehole apparent resistivity of small distance have not been basically affected by these factors,and enhances observation efficiency.

关 键 词：井下地电阻率 影响因素 北京地区 年变化 干扰 

分 类 号：P315.7[天文地球—地震学]