新疆地区地下流体异常特征统计分析及预报效能检验

STATISTICAL ANALYSIS OF ANOMALY CHARACTERISTICS OF GROUND FLUID IN XINJIANG REGION AND VERIFICATION OF PREDICTION EFFICIENCY

基于《中国震例》(1966-2018年)系统分析新疆地区地震前地下流体前兆异常特征,对各测项进行不同震级档预报效能检验。结果表明:新疆地下流体异常数量多集中在100~200 km,异常持续时间多为震前半年内;M_(S)≤6.5地震新疆地下流体异常测项的平均数量为4项;震前异常月频次主要表现为“持续增长”型和“先增后减”型;新10测点和新04测点是新疆地下流体观测点中的异常“敏感点”,其所在区域及附近可被视作构造“敏感区”;利用R值评分方法对各测项预报效能进行检验,其结果显示不同震级档的R值结果有利于分析提取相应震级所适合的异常指标。

Based on the“China Earthquake Examples”(1966~2018),the characteristics of ground fluid precursor anomalies before earthquakes in Xinjiang region were systematically analyzed,and the prediction effectiveness of different magnitude ranges was tested for each measurement item.The results show that the number of ground fluid anomalies in Xinjiang is mostly concentrated in 100~200 km,and the duration of anomalies is mostly within half a year before the earthquake;The average number of ground fluid anomalies in Xinjiang during earthquakes with M_(S)≤6.5 is 4;The monthly frequency of anomalies before earthquakes is mainly manifested as a“sustained growth”type and a“first increase then decrease”type;Xin10 and Xin04 measuring points are abnormal“sensitive points”in ground fluid observation points in Xinjiang,and their location and vicinity can be considered as structural“sensitive areas”;The R value scoring method was used to test the prediction effectiveness of each measurement item,and the results showed that the R value results of different magnitude ranges were conducive to analyzing and extracting anomaly indicators suitable for the corresponding magnitude.