内蒙古和林格尔6.3级地震前地震的空段异常

1976年4月6日内蒙古和林格尔6．3级地震是华北北部地区1次重要的地震，该地震前出现了明显的地震空段异常。介绍了该地震空段的时空特征，分析了地震空段的形成至解体与中强地震成组活动的关系。认为，地震空段可作为华北北部地区中强地震预测的中期判据，这对该地区地震预测有帮助意义。

Earthquake Gap Anomaly before Horinger,Inner Mongolia,Earthquake of M 6.3

The Apr.6,1976 Helingeer earthquake of M6.3 is one of important earthquakes in northern part of the North China. There was an obvious earthquake gap anomaly before this event. The time-space feature of this earthquake gap is introduced. The relation between the earthquake gap from formation to decomposition and the composed activities of medium-strong earthquakes.The author propose that a earthquake gap can be taken as a medium-period criteria for predicting medium-strong earthquakes of northern part of the North China, which is helpful for earthquake prediction of this area.