Recurrence characteristics of late-quaternary strong earthquakes on the major active faults along the northern border of Ordos block  

作　　者：RAN Yongkang (冉勇康) CHEN Lichun (陈立春) YANG Xiaoping (杨晓平) HAN Zhujun (韩竹军) 

机构地区：[1]Institute of Geology, China Seismological Bureau, Beijing 100029, China Institute of Geology, China Seismological Bureau, Beijing 100029, China Institute of Geology, China Seismological Bureau, Beijing 100029, China Institute of Geology, China Seismological Bureau, Beijing 100029, China

出　　处：《Science China Earth Sciences》2003年第z2期189-200,共12页中国科学（地球科学英文版）

摘　　要：Through study on trenches, analysis of recurrence characteristics and recurrence interval cluster/gap of strong earthquakes along the major active faults on the northern border of Ordos block, we found 62 paleoearthquakes that occurred in the late Quaternary, including 33 earthquakes occurring in the Holocene. The recurrence characteristics of the paleoearthquakes are different at three levels, segments, faults, and fault zones. The strong seismic sequence on the independent segments is mostly characterized by long- and short-interval recurrences, while that on the faults and in fault zone is characterized clearly by random and cluster recurrences. Results of the moving window test indicate that the probabilities of "temporal cluster or gap", caused by random coincidence as opposed to intersegment contagion, are 64% and 70% for the Serteng piedmont fault and for the south-border fault of Wula Mountains, respectively, no clear interaction among the segments of each fault; while the probability is 26.8% for the whole fault zone, suggesting a clear interaction among the faults of this fault zone. These recurrence characteristics may imply an effect of the entire block motion on the recurrence of strong earthquakes. Moreover, the elapsed time for the Wujumeng Pass-Dongfeng Village segment of Serteng piedmont fault and the Tuzuo Banner-Wusutu and the Hohhot segments of Daqingshan piedmont fault has exceeded the average recurrence interval, hence these three segments may be the possible places for future strong earthquakes.

关 键 词：ORDOS block  north-border fault zone  paleoseismic events  RECURRENCE characteristics. 

分 类 号：P315[天文地球—地震学]