四川红莫温泉的水文地球化学特征及其与地震的关系

Hydrogeochemical Characteristics of Hongmo Hot Spring in Sichuan Province and Its Relationship with Earthquakes

温泉水文地球化学方法已经广泛应用于地震短临前兆的研究中。红莫温泉位于安宁河断裂带南段,该温泉水样的常量元素分析结果表明,红莫温泉水的化学类型主要为Na-HCO_(3)型;氢氧同位素分析显示地下水的现代补给主要来自大气降水,补给高程约为407~619 m;微量元素分析表明温泉水在循环过程中与围岩发生了低程度的水-岩反应。据SiO_(2)温标计算,其热储温度为63.7℃,循环深度在2.52 km。研究红莫温泉水文地球化学特征变化与地震的关系发现,温泉水的Cl^(-)、 Na^(+)、 SO_(4)^(2-)和δD在2020年巧家5.0级地震、 2022年宁蒗5.5级地震、 2022年芦山6.1级地震和2024年鲁甸4.9级地震前后有不同程度的异常反应。因此,红莫温泉是理想的温泉水文地球化学地震短临监测点。

Hydrogeochemical methods of hot springs are widely used in the research of seis-mic short-impending precursors.Hongmo hot spring is located in the southern section of the Anninghe fault.According to the analysis of the major elements in the water samples from Hongmo hot spring,its main hydrochemical type is Na-HCO_(3).The test of hydrogen and oxygen isotopes in Hongmo hot spring shows that meteoric water is the modern re-charge of groundwater,with a replenishment elevation of about 407~619 m.The analysis of trace elements indicates that there is a low degree of water-rock interaction between the hot spring water and surrounding rock during the water cycle.According to the SiO,tem-perature scale,the heat storage temperature is 63.7℃,and the cycling depth is 2.52 km.Research on the relationship between the hydrogeochemical characteristics of Hongmo hot spring and earthquakes shows that before and after the 2020 Qiaojia M5.O earthquake,2022 Ninglang M5.5 earthquake,2022 Lushan M6.1 earthquake,and 2024 Ludian M4.9 earthquake,the Cl^(-),Na^(+),SO_(4)^(2-),and D showed different degrees of anomalies.There-fore,Hongmo hot spring is an ideal site for short-impending seismic monitoring through hydrogeochemistry.