华南地区震群活动的中短期时空特征研究  

Study on the Medium-and Short-term,Temporal and Spatial Characteristics of Earthquake Swarm Activities in South China

作　　者：黎明晓[1] 余怀忠[1] 薛艳[1] 闫伟[1] 姜祥华 LI Mingxiao;YU Huaizhong;XUE Yan;YAN Wei;JIANG Xianghua(China Earthquake Networks Center,Beijing 100045,China)

机构地区：[1]中国地震台网中心,北京100045

出　　处：《地震研究》2025年第2期289-299,共11页Journal of Seismological Research

基　　金：国家自然科学基金联合基金(U2039205);中国地震局震情跟踪项目(2024020502);国家重点研发计划(2018YFE0109700)。

摘　　要：研究了2010—2023年华南地区M_(L)≥2.0震群在不同时间窗的频次与中强地震的关系;在预测效能评价的基础上,分析了华南地区震群活动的中短期时空特征;结合地震活动和地球物理观测异常,讨论了中强地震的孕震过程。结果表明:(1)华南地区M_(L)≥2.0震群2个月频次N≥4,是M_(S)≥5.0地震的最优中短期预测指标,优势预测时间为200 d,同时R=0.48,R_(0)=0.40;(2)华南地区震群3个月频次N≥4,是M_(S)≥5.0地震较好的短期预测指标,优势预测时间为20 d,同时R=0.43,R_(0)=0.34;(3)活跃时段的震群空间分布对M_(S)≥5.0地震的发震地点有一定的指示意义,但震群空间分布范围较大,在开展地震预测工作时还需结合其它预测方法确定危险区域;(4) 2019年广西北流5.2级和靖西5.2级地震前约8个月(中期),地球物理观测异常增加,地震前约6个月(中短期),M_(L)≥2.0震群活跃,地震前约3个月(短期),M_(L)≥3.0小震活跃度增强。地震活动与地球物理观测异常准同步活动,反映了震前区域应力场的增强。This article studies the relationship between the frequency of earthquake swarms(M_(L)≥2.0)in different time windows and moderate-and strong-earthquakes in Southern China.After the predictive performance evaluation,we analyze the medium-and short-term,spatial,temporal characteristics of earthquake-swarm activity in South China.In addition,we discuss the seismogenic process based on the seismic activity and geophysical observation anomalies.The results show that:①The frequency of the earthquake swarms(M_(L)≥2.0)in Southern China in 2 months is equal to or greater than 4.This frequency is the optimal indicator predicting earthquakes(M_(S)≥5.0)in short-and medium-term.The most probable prediction period is 200 days(R=0.48,R_(0)=0.40);②The frequency of the swarms(M_(L)≥2.0)in Southern China in 3 months is equal to or greater than 4.This frequency is the optimal indicator predicting earthquakes(M_(S)≥5.0)in short-and medium-term.The most probable prediction period is 20 days(R=0.43,R_(0)=0.34);③The spatial distribution of active earthquake clusters has a certain indication of the epicenter of future earthquakes(M_(S)≥5.0)in South China,but the range of seismic clusters is relatively large,so when predicting earthquakes,one should refer to other prediction methods to determine the potential earthquake location;@The number of short-term geophysical anomalies increased proximately 8 months before the Beiliu M_(S)5.2 earthquake and the Jingxi M_(S)5.2 earthquake in Guangxi.The seismic swarm was active about 6 months before the two earthquakes.And small earthquakes were active approximately 3 months before the two earthquakes.Earthquake activity synchronized with the geophysical anomalies,reflecting the enhancement of the regional stress field before the two earthquakes.

关 键 词：华南震群 中短期 时空特征 效能检验 

分 类 号：P315.75[天文地球—地震学]