强震水氡前兆场异常特征及其物理解释

Anomaly Characteristics of Radon Precursory Fields in Groundwater befor Strong Earthquakes and Their Physical Explanation

研究了岩石中微裂隙的产生与地下水氡浓度变化的关系以及孕震过程中微裂隙时空变化图像,揭示了水氡前兆场的时空变化特征及其物理机制。结果表明,孕震过程中岩石微破裂的生长是导致地下水氡含量升高及地震前出现水氡异常的原因;震源区及附近地区的膨胀和微破裂最早出现,并最为发育和集中,因此水氡异常也最早出现,也最为集中;孕震过程中微破裂增加,导致地下水氡含量升高,水氡趋势异常以趋势性升高为主。

Based on the study of relationship between micro-fissure generation in rock and radon concentration in groundwater ,as well as the micro-fissure spatial-temporal changing image in the process of earthquake preparation, the spatial-temporal characteristics of radon precursory field and its physical mechanism are exposed. The results show that the augment of radon content in groundwater and radon anomalies before earthquake are caused by micro-fissure generation in rock in the process of earthquake preparation. Radon anomalies first emerges and mainly focus in the source and adjacent region because dilatancy and micro-fissure first emerge and concentrated also in this region. Increased micro-fissure produces increasing content of radon in the groundwater, so the tendency anomaly of radon exhibits mainly a rising tendency.