新丰江水库显著地震前小震序列特征及应用研究

新丰江水库地区是近年来东南沿海地震带地震最为活跃的地区, 相继在2012年2月16日、 2013年2月22日发生了M_L5.2、 M_L5.1地震。 本文利用新丰江水库地区地震序列的分区丛集性, 通过研究各分区1972年以来的11次M_L4.5以上显著地震前小震序列, 发现11次地震中有8次震前90天内小震经历了“平静—活跃—平静—发震”的演化过程。 为了将研究成果应用于日常的震情预测工作中, 文中借鉴气象暴雨预警中的蓝—黄—橙—红四色分级预警模式, 提出了适合于小震丛集地区日常震情预测的分级危险度模式, 并利用新丰江锡场和大坝区2011年来的小震目录给出了应用实例。 实践证明此种方法最大的优势是可以给出预测区地震危险性相对的变化, 从而可以对区域的震情演化有一个较好的把握。

Sequence Characteristics before Significant Earthquakes and Application in the Xinfengjiang Reservoir

The Xinfengjiang reservoir has been the most active area of the southeast coastal seismic zone in recent years, where occurred M_L5.2 and M_L5.1 earthquakes in February 16, 2012 and February 22, 2013 respectively. Based on spatial clustering of earthquake in Xinfengjiang reservoir, we study sequences of small earthquake before 11 significant earthquakes above M_L4.5 since 1972, and obtain “calm-active-quiet-earthquake” evolutionary characteristics 90 days before 8 significant earthquakes. In order to apply the research results to the daily work of earthquake prediction, we put forward a classified risk model suitable for daily earthquake prediction of cluster area of small earthquakes by referring to “the blue-yellow-orange-red” alert classification model similar to the meteorological storm warning, and give application examples by small earthquake catalogue of Xichang and the dam area of Xinfengjiang since 2011. Practice shows that the biggest advantage of this method is to provide relative change of seismic risk, so that we can have a better grasp of regional seismic evolution.