A 700-year record (1.0-1.5 a resolution) of the East Asian winter monsoon (EAWM),based on grain-size analysis and AMS14C dating of Core EC2005 from the inner-shelf mud wedge of the East China Sea (ECS),was compared wi...A 700-year record (1.0-1.5 a resolution) of the East Asian winter monsoon (EAWM),based on grain-size analysis and AMS14C dating of Core EC2005 from the inner-shelf mud wedge of the East China Sea (ECS),was compared with the Dongge stalagmite δ18O record during the mid-Holocene.The upper muddy section of Core EC2005 has been formed mainly by suspended sediments derived from the Changjiang (Yangtze) River mouth since 7.3 ka BP.High precipitation and a strengthened EAWM might have played key roles in the high sedimentation rate (1 324-1 986 cm/ka) between 5.9-5.2 ka BP.The EAWM strengthened when the Asian summer monsoon weakened,especially around 5500 a BP,which corresponded to a worldwide cold event.The EAWM during the mid-Holocene shows statistically significant solar periodicities at 62 and 11 a.The 5500 a BP cold event might be resulted from orbital forcing and changes in solar activity.展开更多
基金Supported by the National Natural Science Foundation of China (Nos. 40576032 and 40776030)Doctor Foundation of China University of Petroleum
文摘A 700-year record (1.0-1.5 a resolution) of the East Asian winter monsoon (EAWM),based on grain-size analysis and AMS14C dating of Core EC2005 from the inner-shelf mud wedge of the East China Sea (ECS),was compared with the Dongge stalagmite δ18O record during the mid-Holocene.The upper muddy section of Core EC2005 has been formed mainly by suspended sediments derived from the Changjiang (Yangtze) River mouth since 7.3 ka BP.High precipitation and a strengthened EAWM might have played key roles in the high sedimentation rate (1 324-1 986 cm/ka) between 5.9-5.2 ka BP.The EAWM strengthened when the Asian summer monsoon weakened,especially around 5500 a BP,which corresponded to a worldwide cold event.The EAWM during the mid-Holocene shows statistically significant solar periodicities at 62 and 11 a.The 5500 a BP cold event might be resulted from orbital forcing and changes in solar activity.
