甘肃东南部水氡中期异常特征研究

Study on Mid-term Anomalies of Radon in Southeast Gansu Province

利用从属函数、变差率以及趋势速率方法提取甘肃东南部水氡观测资料的地震前兆异常。结果表明,1984年1月至2009年12月,7项水氡资料共出现47次从属函数异常、45次变差率异常和39次趋势速率异常。其中,33次从属函数异常、35次变差率异常和30次趋势速率异常很好地对应了甘肃及邻区震中距在33~585 km范围内发生的5~8级地震。通过分析异常特征及其与地震的关系,提出中强震和强震时间预测的指标与方法,得出甘肃东南部水氡从属函数计算的经验常数,以及变差率和趋势速率的异常阈值。

Using the methods of subordinate function,variation rate and trend rate,we extract the earthquake precursory anomalies from observational data of Radon in southeast Gansu Province.The result indicates that 7 items of radon data include 47 subordinate-function anomalies,45 variation-rate anomalies and 39 trend-rate anomalies from January 1984 to December 2009.Among them,33 subordinate-function anomalies,35 variation-rate anomalies and 30 trend-rate anomalies corresponded with the earthquakes MS5-8 that ever hit Gansu Province and the adjacent region within 33 to 585 km.By the analysis of the features of these anomaies and their relation to the earthquakes,the method of time prediction for the moderate-strong and strong earthquake were proposed,and the empirical constant,variation rate and threshold value of trend-rate anomaly are obtained from Radon in southeast Gansu Province.