云南强震地下流体源兆特征研究

Study on characteristics of source precursors of under ground fluid for great earthquakes in Yunnan region

区分"源兆"与"场兆",系地震预测探索中的重要课题。根据云南4组6级以上地震的地下流体前兆异常资料,系统分析了强震源兆的流体前兆异常特征。结果表明,在6级多强震的源兆区,即震中距100 km范围内,异常项目计有水位、水温、水氡、水汞及气汞;以中期、短期异常为主,临震异常很少;源兆异常台站和台项的比例均高于场兆。这些流体源兆特征的认识,可为利用流体异常判断地震危险区提供一定依据。

It is an important topic to distinguish between the source precursor and the field precursor in the exploration of earthquake prediction. Based on the precursor anomaly data of under ground fluid before 4 group earthquakes with Ms≥6.0 in Yunnan Province, we systematical- ly analyzed the under ground fluid precursor anomaly feature before strong earthquake. The results show that in the source precursor area of earthquakes with Ms≥6.0 （epicentral distance within 100km） the anomalies contain water-level, water temperature, radon content in groundwater.mercury content in groundwater and mercury content in gas, which are mainly medium-term and short-term anomalies, and the impending-earthquake precursor anomalies are few. The proportion of anomaly stations and items in source precursor region are higher than field precursor region. The results of the characteristics of under ground fluid source precursors can be provide some basis when iudging the seismic dangerous zone using under ground fluid anomalies.