Paleo-Earthquakes along the Zheduotang Fault,Xianshuihe Fault System,Eastern Tibet:Implications for Seismic Hazard Evaluation  

作　　者：Guifan Chen Mervin Bartholomew Demin Liu Kai Cao Minxuan Feng Dun Wang 

机构地区：[1]School of Earth Sciences,China University of Geosciences,Wuhan 430074,China [2]Three Gorges Geotechnical Consultants Co.,Ltd.,Wuhan 430074,China [3]Department of Earth Sciences,University of Memphis,Memphis,TN,38152,USA [4]Xi’an Center of Geological Survey,China Geological Survey,Xi’an,710054,China

出　　处：《Journal of Earth Science》2022年第5期1233-1245,共13页地球科学学刊（英文版）

摘　　要：The Kangding City in eastern Tibet is at high risk due to frequent strong earthquakes along the Xianshuihe sinistral strike-slip fault bounding the Chuandian Block to the northeast.The knowledge of paleo-seismicity recurrence along this fault system is key to the evaluation of earthquake hazards in this region;thus,more accurate paleoseismic information are required.We examined the paleo-seismicity along the Zheduotang fault in the central segment of the Xianshuihe fault system by applying the field investigation,trenching,and Quaternary dating methods(e.g.,OSL and ^(14)C).Field observations found~8.5 m offset of stream by sinistral slip along the Zheduotang fault.We trenched the central fault zone of the Zheduotang fault and found that the colluvial wedges and five buried,discontinuous,A-soil horizons progressively have been offset in the shallow graben on the SW-side of the main fault indicative of the paleo-earthquakes.The dating results of OSL and ^(14)C,in line with existing data,enable us to establish the paleo-seismic history of the Zheduotang fault.It shows at least eight surface ruptures in the last 7500 years identified from displaced buried soils,colluvial wedges and terraces.Our study reveals~100 years minimum paleo-earthquake recurrence,suggesting potential large earthquakes in the Kangding area in the future.

关 键 词：Tibetan Plateau Xianshuihe fault system paleo-seismicity TRENCH RECURRENCE GEOPHYSICS 

分 类 号：P315[天文地球—地震学]