末次冰消期气候转型对青藏高原东部地震活动的影响  

The Impact of Climate Transition on Seismic Activities on the Eastern Margin of the Tibetan Plateau during the Last Deglaciation

作　　者：钟宁 蒋汉朝[2] 李海兵[3] 徐红艳[2] 梁莲姬 ZHONG Ning;JIANG Han-chao;LI Hai-bing;XU Hong-yan;LIANG Lian-ji(Key Laboratory of Neotectonic Movement and Geohazard,Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081;State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029;Key Laboratory of Deep-Earth Dynamics,Ministry of Land and Resources,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037;College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100124)

机构地区：[1]新构造运动与地质灾害重点实验室,中国地质科学院地质力学研究所,北京100081 [2]地震动力学国家重点实验室,中国地震局地质研究所,北京100029 [3]自然资源部深地动力学重点实验室,中国地质科学院地质研究所,北京100037 [4]北京工业大学建筑工程学院,北京100124

出　　处：《地球学报》2021年第1期21-31,共11页Acta Geoscientica Sinica

基　　金：国家自然科学基金项目(编号:41807298,41702372,41572346);中国博士后基金(编号:2019M650788);中国地质调查局项目(编号:DD20190319,DD20190059)联合资助。

摘　　要：探讨构造和气候在地质演化过程中的耦合作用一直是地球系统科学研究的热点。通过对青藏高原东部古地震和古气候资料的收集和分析,发现18-15 ka期间湖相沉积存在大量且强烈的地震成因软沉积物变形构造或地震事件,可能是末次冰消期以来青藏高原大陆冰川(或冰帽)快速消融和冰川剥蚀卸载作用,引起中上地壳应力卸载和均衡反弹,以及冰川融水引起地下水波动,导致区域应力场变化和断层活动增强,诱发了区域频繁的地震所致。本研究为更好地理解晚第四纪青藏高原东部的地震活动、气候变化和地貌过程具有一定的启示意义。The coupling of tectonic and climate is a hot topic in the earth system science.Through the collection and analysis of paleoearthquake and paleoclimatic data during the last deglacial(18–15 ka)in the eastern Tibetan Plateau,the authors found a large number of strong earthquake-induced soft sediment deformation structures or paleoseismic events in lacustrine sediments.During the 18–15 ka,the Longriba fault,the Longmenshan fault,the Xianshuihe fault,the Daduhe fault,and the Chenghai–Binchuan fault experienced paleoearthquakes or seismic landslide.During the last deglacial period,the rapid melting and erosion of mountain glacier(or ice cap)unloading in the Tibetan Plateau might have caused the stress unloading or isostatic rebound of the middle and upper crust,and the fluctuation of groundwater caused by glacial meltwater resulted in regional stress field changes and enhanced fault activity,which induced frequent seismic activity in this area.It is considered that the periodic glacial to interglacial or climate transition stage had a major impact or a significant impact on the terrain,landform,vegetation,and hydrology,and also the possible changes in regional tectonic stress fields and coulomb stress,periodic growth and extinction of ice sheets,groundwater hydrological fluctuations,as well as river erosion.The results obtained by the authors provide a better understanding of the patterns of tectonic activity,climate change,and geomorphic processes in the eastern Tibetan Plateau.

关 键 词：软沉积物变形构造 古地震 地壳均衡反弹 青藏高原东部 末次冰消期 

分 类 号：P548[天文地球—构造地质学] P532[天文地球—地质学]