首都圈地区M_S5.0级以上地震前地震活动图像

Study on Seismicity Pattern before M_S5.0 Earthquakes in the Capital Area

针对地震前经常出现的地震活动图像异常展开研究,分析了首都圈地区1970年以来MS5.0级以上中强震前地震活动图像的变化特征。结果显示,首都圈地区8次(组)MS5.0级以上地震前,在震源区附近均出现了地震条带和逼近地震,震前有87.5%的逼近地震距主震130 km内;87.5%地震前在震源区附近出现了孕震空区,并在空区边缘或空区内部出现了逼近地震。最后对地震活动图像异常特征与首都圈地区中强震的相关性进行了讨论。

This paper studies the pre-earthquake abnormal seismicity patterns,analyses the characteristics of seismicity pattern before moderate-strong earthquake of MS≥5.0 in the Capital area since 1970.The result indicates that in source region of eight moderate-strong earthquakes in the Capital area,seismic belt and approaching earthquakes appears,and 87.5% of the approaching earthquakes are within 130 km radius of the main earthquake.Before 87.5% of the eight moderate-strong earthquakes,seismic gap forms in the source region with approaching earthquakes occur in the verge of the seismic gaps or inside it.This paper also discusses the relationship between the characteristics of seismicity pattern anomalies and the moderate-strong earthquakes in the Capital area.