南京地电阻率长趋势变化与区域应力调整的关系研究

江苏南京台北南测道2013—2016年年初出现了与邻近的南京江宁台同步的地电阻率长趋势上升变化,2016年的年中出现了与江宁台和稍远距离的江苏高邮、新沂台同步的趋势下降变化。本文用年变形态、消除年变等数据处理方法并联系该区降雨量分析了南京台等地电阻率长程观测数据,基于视电阻率变化与地下介质内部骨架电阻率ρ°、裂隙水电阻率ρf、裂隙率ν之间的本构关系讨论了地电阻率趋势变化的原因,得到:该台南北向测道地电阻率趋势上升变化起因于台站及周边区域性地下介质的应力调整过程,动力来源可能是本区域地壳局部构造运动。

Relationship between Long-Time Trend Change of Earth Resistivityat Nanjing Station and Regional Stress Adjustment

From 2013 to the beginning of 2016,the earth resistivity in the north-south(NS)channel at Nanjing station showed a long-time trend change of rising synchronization with the adjacent Jiangning station.In mid-2016,it showed a synchronous downward trend with Jiangning,Gaoyou,and Xinyi stations.In this study,the long-range observation data of earth resistivity at Nanjing station,combined with the rainfall in the study area,were analyzed using data processing methods.The cause of the trend change of earth resistivity was discussed based on the constitutive relationship of the apparent resistivity change with parametersρ°,ρf,andν.Results show that the rising trend of earth resistivity in the NS channel at Nanjing station is due to the stress adjustment process of the regional underground media in the station and its surrounding area,and the dynamic source may be the local tectonic movements of the crust in this area.