江西流体观测井网对远大震的同震响应特征及机理分析

Features and mechanism of co-seismic responses of Jiangxi groundwater level and temperature to far-field strong earthquakes

选取2008—2022年全球M_(S)8.0以上、全国M_(S)7.0以上22个地震事件,分析江西省流体井网水位、水温测项对远大地震的同震响应特征。结果发现:不同流体井的同震响应特征不同,不同测项的同震响应特征也不一致,且井水位对地震的响应频率较高;井水位对远大震的同震响应以阶跃、震荡及持续变化为主,而水温同震响应以阶跃为主,且具有瞬时变化和持续变化2种特征;同一口井对不同地震的响应形态基本相同,而不同井对同一地震的响应形态有所区别。通过对观测井水位和水温同震响应机理的分析,认为江西流体观测井不同测项变化与井孔水文地质条件及观测系统有关。

Based on 22 strong earthquakes that occurred during 2008-2022,we analyze the features of the co-seismic response of Jiangxi groundwater level and temperature and summarize post-earthquake morphology.The results show that in general,the response frequency of water level is higher than that of water temperature.The forms of the co-seismic response of water level to distant strong earthquakes are step change,oscillation,and sustained change.The co-seismic response of water temperature is mainly step change,which has two characteristics transient and continuous variation.The response patterns of the same well to different earthquakes are basically the same,different wells have different responses to the same earthquake.Based on the analysis of the mechanism of the co-seismic response of groundwater level and temperature,it is considered that the variation of different co-seismic responsesis related to the well hydrogeological conditions and observation systems.