漾濞6.4级地震前后大理地区温泉水化学组分特征分析

Analysis of Chemical Composition Characteristics of Hot Spring Water in Dali Area Before and After the Yangbi M6.4 Earthquake

2021年6月21日在云南省大理白族自治州漾濞县发生M6.4级地震。通过对大理地区主要断裂带温泉水化学组分每季度定期取样观测,分析该区地下水的化学类型、成因及其与地震活动的关系。测定、分析结果显示:洱源温泉属于HCO_(3)·SO_(4)-Na型水,白总旗温泉属于HCO_(3)·Cl^(-)Na型水,高芹、剑川、永胜、漕涧温泉均属于HCO_(3)^(-)Na型水;温泉水氡水汞背景值高,具有一定的区域性;洱源,弥渡,剑川温泉可能受大理地区广泛分布的石炭—二叠系海相沉积灰岩影响,显示较高的HCO_(3)^(-)、Ca^(2+)含量;漾濞6.4级地震前后区域内温泉水的Cl^(-)、SO_(4)^(2-)、水汞、水氡含量有明显变化,白总旗温泉Cl^(-),永胜、洱源温泉SO_(4)^(2-)以及高芹温泉水汞含量在漾濞6.4级地震前明显上升,震后含量显著下降,温泉水温和固体CO_(2)含量变化不明显。

An M6.4 earthquake occurred in Yangbi County,Dali Bai Autonomous Prefecture,Yunnan Province On June 21^(st),2021.By sampling and observing the chemical components of the hot spring water in the main fault zones in Dali area every quarter,the paper analyzes the chemical types and causes of groundwater in this area and their relationship with seismic activity.The measurement and analysis results show that:Eryuan hot spring belongs to HCO_(3)•SO_(4)-Na type water,Baizongqi hot spring belongs to HCO_(3)•Cl^(-)Na type water,Gaoqin,Jianchuan,Yongsheng and Caojian hot springs all belong to HCO_(3)^(-)Na type water;the background value of radon and mercury in hot spring water is high and has a certain regional;Eryuan,Midu and Jianchuan hot springs may be influenced by the Carboniferous-Permian marine sedimentary limestone widely distributed in Dali area,showing high HCO_(3)^(-),Ca^(2+)content;the contents of Cl^(-),SO_(4)^(2-),mercury and radon in hot spring water in the area before and after the Yangbi M6.4 earthquake changedsignificantly.The content of Cl^(-)in Baizongqi hot spring,SO_(4)^(2-)in Yongsheng and Eryuan hot springs,and the mercury content in Gaoqin hot springs increased significantly before the Yangbi M6.4 earthquake,and decreased significantly after the earthquake.The temperature of hot spring water temperature and solid CO_(2) content did not change significantly.