关键词: 古地震, 地震复发, 地震危险性预测, 地震复发间隔

Abstract: A detailed study of paleoearthquakes in Yanhuai basin and along Haiyuan fault of China shows that recurrence behavior of large earthquakes is of variery. Characteristic earthquake is common behavior of fault activity and there is grading of characteristic earthquakes. Besides, there is phasing of recurrence behavior of large earthquakes and the interaction between segments and (or) faults. These must influence the recurrence behavior of large earthquakes. Then, when the phasing of recurrence behavior appears and when the characteristic earthquakes of different intensity cause different interval time of recurrence, we must take trend average value of recurrence interval for assessing hazard of large earthquakes using either definite method or probability method. For example, the different average value is taken as fault behavior is during long-interval between event clusters and as it is during short-interval in a cluster. Characteristic earthquakes occurred on a master segment have different average value of recurrence interval from those occurred on a secondary segment so the different average value should be taken.

Key words: Paleoearthquakes, Earthquakes recurrence, Assessment of earthquake hazard, Earthquake recurrence interval.