CHARACTERISTICS OF EARTHQUAKE ACTIVE INTERVAL IN HEBEI AND ITS NEIGHBORING AREA

the history and definition to study earthquake active interval are introduced, and the statistical graph for the distribution of the intervals as well as statistical graph of interval-frequency in Hebei and its neighboring area are analyzed.In analysis we considered the following factors:magnitude level, length of statistical interval, active level and cluster grouping and isolation in occurrence.The results show that the logarithm of interval-frequency assumed exponential distribution, so did the G-L relation.