华北地区震群活动与强震  

Relationship between Earthquake Swarms and the Strong Earthquake in North China

作　　者：薛艳[1] 陈琳荣[2] 黎明晓[1] 刘双庆[3] 

机构地区：[1]中国地震台网中心,北京100045 [2]吉林省地震局工程地震研究所,长春130022 [3]天津市地震局,天津300201

出　　处：《华北地震科学》2017年第2期1-9,共9页North China Earthquake Sciences

基　　金：地震科技星火计划项目"全球巨大地震前地震活动及序列演化特征研究"(XH17048);震情跟踪项目"华北地区6级以上地震危险性研究"(2017020504)

摘　　要：通过系统研究华北地区震群活动与强震的关系,发现:(1)震群活动与区域强震关系密切,小震群频度的起伏可以反映区域地震活动水平的强弱;(2)华北地区M_L≥2.0震群半年累积频度N≥8可以作为区域M_S≥5.7地震的预测指标,预测时间为异常出现后的10个月内,预测效能评分R=0.615,大于具有97.5%置信水平的R0(0.437);(3)震群频度指标可以通过Molchan模型检验,对于不同强度的目标地震(M_S≥5.0、M_S≥5.5与M_S≥5.7地震),其预测效能均好于Poisson模型,其中60%目标地震的预测概率增益可以达到2~4水平;(4)区域震群对强震地点的预测意义有限:在张北6.2级、瑞昌5.7级与前郭5.8级地震前2年,与强震相关的构造带震群活跃;震前中短期阶段(2~10个月),震群向震中及周边迁移;而对其余4次强震,震群对发震地点没有指示意义。The relationship between earthquake swarms and the strong earthquake in North China has been studied, the results show： （1）Earthquake swarm activity is closely related to regional strong earthquakes, and the frequency of small swarms can reflect the level of regional seismic activity. （2）The half year cumu- lative frequency of ML≥2. 0swarms great than or equal to 8 can be used as a predictive index of Ms≥ 5.7earthquakes. The prediction time is 10 months after the appearance of the anomaly. The value of the predictive efficacy score R is 0. 615, greater than that of R0, 0. 437, with a 97.5% confidence level. （3） Frequency index of earthquake swarms can be tested by Molchan model. For target earthquakes with Ms≥5.0,Ms≥5.5 and Ms≥5.7 respectively, the predicted results are all better than the Poisson mode prediction probability gain can be achieved 2 ~4 for the 60% of the target earthquakes especially. place prediction of earthquake swarms to the strong earthquake is limited. Two years before the Zh Ms6.2, Ruichang Ms5.7 and Qianguo Ms5.8 earthquake, swarms are mainly active in the vicinity tectonic zones associated with the strong earthquake. While they migrate to the epicenter and the surounding area 2 months to 10 months before the strong earthquake. But for the rest strong earthq the place prediction of swarms is not significant.

关 键 词：华北地区 震群 强震 统计检验 预测指标 

分 类 号：P315.2[天文地球—地震学]