川西温泉水温观测及其在芦山M_S7.0地震前的异常现象

Hot spring water observations and its anomalies before the Lushan M_S7.0 earthquake in the western Sichuan region

在2013年芦山MS7.0地震震中附近流体观测点进行现场考察的基础上,本文选择川西地区观测环境较好、干扰较少的温泉水温观测资料进行回溯性分析.结果表明,康定龙头沟和二道桥温泉、道孚龙普沟温泉、理塘毛垭温泉、泸定共和温泉水温在芦山地震前均出现不同程度的异常变化.其主要表现为,距离震中较远的理塘毛垭温泉和道孚龙普沟温泉水温在震前2年左右出现中期尺度异常,距离震中较近的康定龙头沟和二道桥温泉水温在震前3个月内出现短期异常.通过温泉水化学及δD-δ18 O稳定同位素特征分析,认为这些温泉水具有深循环特征,能灵敏地反映地壳深部地热及构造变化信息,是芦山地震前观测到异常的可能原因.加强对这些温泉点的观测,对区域地震预测研究具有重要的科学意义和现实意义.

On the basis of field survey of fluid observation sites near the epicen-ter of 2013 Lushan MS 7.0 earthquake,hot spring temperature data observed at the sites with better observation environment and little human disturbance in the western Sichuan Province were selected to perform retrospective analysis. The results showed that different degrees of water temperature anomalies were observed at Longtougou and Erdaoqiao sites in Kangding region,Longpugou site in Daofu county,Maoya site in Litang county,Gonghe site in Luding coun-ty before the Lushan MS 7.0 earthquake.It was mainly showed that the mid-term anomalies about two years of time scale were observed at Maoya and Long-pugou hot spring sites far from the epicenter of Lushan earthquake;while the short-term anomalies within three months preceding the earthquake were ob-served at Longtougou and Erdaoqiao hot spring sites which were close to the earthquake epicenter.By the spring water hydrochemistry and δD-δ18 O stable isotopes analysis,it was suggested that these hot spring water have deep circu-lation characteristics,so the temperature changes of hot spring water can sensi-tively reflect deep crustal information in respect of geothermal and tectonic changes,which was the possible cause for the anomalies observed at the hot spring water preceding the Lushan earthquake.It was significant for the region-al earthquake prediction research to strengthen observation of these hot spring sites.