【摘要】 从1976年4月6日内蒙古和林格尔MS6.3地震起,华北北部地区中强地震活动呈现活跃态势,表现出3组中强地震成组活动的特点。介绍了这3组中强地震成组活动的时、空特征及迁移规律。指出,这些研究对提高华北北部地区的地震预测水平有一定意义。更多还原

【Abstract】 The medium-strong earthquake activity in the north area of the North China has been appeared active trend,which is showed by group activity characteristic of three sets of medium-strong earthquakes since the Apr.6,1976 Helinger earthquake of M6.4.Time and spatial characteristic and migration law of these sets of medium-strong earthquakes are introduced.It is pointed out that this research is significant for heightening earthquake prediction level for the north area of North China.更多还原