湖北万山井水温动态特征

Dynamic characteristics of water temperature in Wanshan well in Hubei Province

以湖北万山井水温观测资料为研究对象,探究井内深度215 m和241.58 m处的水温动态特征及其主要干扰因素和映震能力。通过水温梯度分析和水温正常动态对比研究,认为:在井深215 m处,水温动态为稳定型;在井深241.58 m处,水温长期动态为升温漂移型,月动态为上升—阶变型,日动态为随机起伏型,升温漂移是仪器自身的零漂现象,随机起伏反映了仪器自身噪音或者对应井水温的随机变化。对水温主要干扰因素的分析表明,井深241.58 m处的水温异常主要来自人为干扰引起的井水震荡和探头线扰动,异常形态均表现为单个台阶或突跳。在2018年9月8日湖北襄阳襄城ML 3.2地震前后,该深度处水温均呈高频V型阶变异常,此为地震发生前后区域应力积累与释放对井水温的作用所致。

This paper takes the water temperature observation data of Wanshan well in Hubei Province as the research object to explore the different water temperature dynamic characteristics at 215 m and 241.58 m,main interference factors,and seismic reflection ability.Through the analysis of water temperature gradient and comparative study of normal water temperature dynamics,it was concluded that the water temperature dynamics at 215 m is stable;however,the long-term dynamics of the water temperature at 241.58 m is warming-drift type,the monthly dynamic is rising-step variation type,and the daily dynamic is random fluctuation type.It is believed that the warming-drift type reflects the baseline drift phenomenon of the instrument itself,and the random fluctuation type reflects the noise of the instrument or the random change of the well water temperature.The analysis of the main interference factors of water temperature showed that the abnormal water temperature at 241.58 m is mainly caused by the well water fluctuation and probe line disturbance caused by human interference,and the abnormal form is a single step or a sudden jump.Before and after the ML 3.2 Xiangcheng earthquake in Xiangyang city,Hubei Province,on September 8,2018,the water temperature at 241.58 m was recorded with high-frequency V-shape step anomalies,which was the interference of regional stress accumulation and release adjustment on well water temperature before and after the earthquake.