云南井网水温和水位对几次典型地震的响应特征研究

Coseismic response characteristics of groundwater temperature and level of Yunnan well network to several earthquakes

基于2008—2023年云南井网中26口观测井水温和水位的同震响应资料,以对云南地区影响较显著的8次地震为例,对比分析各观测井水温和水位的同震响应特征,分别从地震波能量密度、岩性、断裂带的控制作用以及动态协调性等角度对其同震响应机理进行了探讨。结果表明,云南井网水温和水位对远场大震的响应较近震显著,响应主要集中在滇中一带,水位响应较水温显著,水位同震变化以振荡和上升为主,水温以脉冲为主。德宏法帕滇22井和丽江象山井有更好的响应能力,剑川滇06井、会泽甘沟滇01井、昆明官渡区小哨井、大姚地温井和南华震2井的同震响应能力较其余21口井弱。进一步分析表明,地震波能量密度与震中距线性拟合相关系数大于−0.9,成明显负相关,与震级成正相关,并给出了能量密度与渗透系数的对应关系。最后分别对水温和水位同震响应机理进行了探讨。

Based on the coseismic response data of water temperature and water level of 26 observation wells in Yunnan well network from 2008 to 2023,the coseismic response characteristics of water temperature and water level of each observation well were compared and analyzed with 8 earthquakes that have a significant impact on Yunnan region.The coseismic response mechanism was discussed from the perspectives of seismic wave energy density,lithology,control of fault zone and dynamic coordination.The results indicate that the response of water temperature and water level in the well pattern of Yunnan to the far-field earthquakes is more significant than near earthquakes,with the response primarily concentrated in the middle of Yunnan.The water level exhibits a more pronounced response than the water temperature.The coseismic variation of water level is mainly characterized by oscillation and rise,while the water temperature is mainly characterized by pulses.Dehong Fapa Dian No.22 well and Lijiang Xiangshan well have better seismic reflection performance in Yunnan well pattern.On the other hand,No.06 well in Jianchuan,No.01 well in Huize Gangou Dian,Xiaoshao well in Kunming Guandu District,Dayao geothermal well,and Nanhua Zhen 2 well exhibit weaker coseismic responses compared to the other 21 wells.Further analysis shows that the linear fitting correlation coefficient between seismic wave energy density and epicenter distance is greater than−0.9,which is significantly negative correlation and positive correlation with magnitude,and shows the corresponding relationship between energy density and permeability coefficient.Finally,we analyzed the mechanism of coseismic response of water temperature and water level.