大同地震水氡动态图像的前兆异常特征

CHARACTERISTICS OF PRECURSOR ANOMALY IN DYNAMIC PATTERN OF RADON IN WATER BEFORE DATONG EARTHQUAKE

采用“九五”攻关提出的水氡动态图像分析方法，对二次大同5．8级地震水氛前兆异常的时空演化特征进行分析研究。简介了大同地震水氡动态图像的生成方法。研究表明，地震前震源区及周围出现水氡变化率≥0．06的异常特征区、异常区的时间演化与地震具有“扩展－急剧扩展－地震－持续扩展－地震－收缩”的关系，且与多种异常发展的中期、中短期和短临阶段相对应；异常区的空间分布演化与震中、地质构造和地热等有密切关系。表明动态图像方法能较完整、直观地揭示水氡前兆异常的特征，可望成为一种水氡分析预报的新方法。

Based on the analytical method of the dynamic pattern that proposed in 'The Ninth Five-year Plan Project', the spatial and the temporal variation characteristics of Radon precursor before two Datong strong earthquakes have been analyzed. The process to form this method has been introduced. The results show that the characteristic region where variation ratio of Radon in the water in the seismic and adjacent region is obvious and large than 0. 06 is existed. The relation in the temporal characteristics between the anomaly region and the earthquakes is expressed as 'Extension-rapid extension-earthquake occurrence-continuous extension earthquake occurrence-contraction'. It is also associated with medium-term, medium-and short term and impending short term anomaly development. The variation of the spatial distribution of the anomaly region is closely related to the epicenter, geological structure and geothermal activity. It is suggested that the dynamic pattern method could completely and directly show the anomaly characteristic in Radon precursor and be a new method of Radon analysis for the earthquake prediction.