Seismogenic Structure of the 1605 Qiongshan M7½ Earthquake and Its Holocene Activity History in Northern Hainan Island, China: Evidence from Cross-Section Drilling and Shallow Seismic Profile  

作　　者：Chaoqun Wang Liyun Jia Daogong Hu Shibiao Bai Zhengwang Hu Dongxia Sun Xiaoxiao Yang Lei Zhang Xiumin Ma 

机构地区：[1]Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China [2]Key Laboratory of Active Tectonics and Geological Safety,Ministry of Natural Resources,Beijing 100081,China [3]Key Laboratory of Geohazard Prevention of Hilly Mountains,Ministry of Land and Resources(Fujian Key Laboratory of Geohazard Prevention),Fuzhou 350002,China [4]Observation and Research Station of Crustal Stress and Strain in Beijing,Ministry of Natural Resources,Beijing 100081,China [5]College of Marine Science and Engineering,Nanjing Normal University,Nanjing 210023,China [6]Hubei Subsurface Multi-Scale Imaging Key Laboratory,School of Geophysics and Geomatics,China University of Geosciences,Wuhan 430074,China

出　　处：《Journal of Earth Science》2024年第3期905-917,共13页地球科学学刊（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.42272222);the Basic Research Funds of Institute of Geomechanics,Chinese Academy of Geological Sciences(No.DZLXJK202211);China Geological Survey(Nos.DD20190306,DD20190546,DD20160269,DD20230249)。

摘　　要：The 1605 M7½ Earthquake is the only earthquake in the history of China that has caused large-scale land subsidence into the sea,with the total area of land subsidence exceeding 100 km2.The disaster has led to the sinking of 72 villages.There is still no clear understanding of the source seismogenic fault of this earthquake.In this work,we conducted a detailed study of the middle segment of the Maniao-Puqian fault(MPF),which is the epicenter area,through geomorphological survey,data collection,shallow seismic exploration,cross-section drilling,and chronological dating.The results showed that the middle segment of the MPF zone is composed of three nearly parallel normal faults with a dextral strike-slip:“Macun-Luodou fault(F2-1),Haixiu-Dongyuan fault(F2-2),and ChangliuZhuxihe fault(F2-3)”.And F2-2 is composed of two secondary faults,namely F2-2′and F2-2″,with a flower-shaped structure buried under the ground.It is distributed nearly east-west,dipping to the north and has experienced at least five stages of activities since the Miocene.The vertical activity rates of F2-2′and F2-2″are~2.32 and~2.5 mm/a,since the Holocene,respectively.There were eight cycles of transgression and regression since the Miocene.The fault activity resulted in the thickening of the Holocene strata with a slight dip to the south,on the hanging wall,showing V-shaped characteristics.The MPF is likely the source seismogenic fault of the M7½ earthquake that hit Qiongshan in 1605.

关 键 词：seismogenic structure EARTHQUAKES Maniao-Puqian fault fault activity history geomorphology. 

分 类 号：P31[天文地球—固体地球物理学]