| WANG Rujian,LI Xia,XIAO Wenshen,XIA Peifen,CHEN Ronghua. 2005. Paleoceanographic records and sea ice extension history on the slope of the northern Bering Sea over the last 100 ka B.P.. Acta Oceanologica Sinica, (6):117－126 |
| Paleoceanographic records and sea ice extension history on the slope of the northern Bering Sea over the last 100 ka B.P. |
| Paleoceanographic records and sea ice extension history on the slope of the northern Bering Sea over the last 100 ka B.P. |
| Received:July 28, 2005 Revised:October 20, 2005 |
| DOI： |
| Key words:surface productivity ice-rafted detritus sea ice extension history late Quaternary Bering Sea |
| 中文关键词: surface productivity ice-rafted detritus sea ice extension history late Quaternary Bering Sea |
| 基金项目: |
| Author Name | Affiliation | E-mail | | WANG Rujian | State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China | rjwang@mail.tongji.edu.cn | | LI Xia | State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China | | | XIAO Wenshen | State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China | | | XIA Peifen | State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China | | | CHEN Ronghua | Key Laboratory of Submarine Geoscience, State Oceanic Administration, Hangzhou 310012, China | |
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| Abstract: |
| Quantitative analytic results of the biogenic components in Core B2-9 from the northern Bering Sea slope indicate that the coarse fraction and opal content, serving as proxies of surface productivity, have increased stepwise since the marine isotope stage(MIS)5.3, reflecting periodic enhancement in surface productivity. The surface productivity attained its highest level during the Holocene, followed by MIS 3.2 to 2 and then MIS 5.3 to 3.3 with a lowest level. High total organic carbon(TOC) contents, together with high C/N ratios,which stand mostly between 7 and 20, show that the TOC was deposited from mixing sources. Therefore,one has to be cautious to use TOC as a proxy of surface productivity. The high TOC and C/N ratio during MIS 5.1, 3.3 to 3.2 and the Holocene reflect that the terrigenous organic matter input increased during interglacial periods. Increases in the fine-and silt-grained terrigenous components from MIS 5.3 to the middle Holocene imply that with the cooling climate, sea ice on the Bering Sea slope extended continuously. Ice-rafted and charcoal detritus increased during glacial, interstadial and the last deglaciation periods and decreased during interglacial periods,suggesting that sea ice on the slope increased and melted, respectively, during glacial and interglacial periods. The extension of sea ice during glacial periods,which was linked with the climate over the North American Continent, responded to global climate change during late Quaternary glacial and interglacial cycles. |
| 中文摘要: |
| Quantitative analytic results of the biogenic components in Core B2-9 from the northern Bering Sea slope indicate that the coarse fraction and opal content, serving as proxies of surface productivity, have increased stepwise since the marine isotope stage(MIS)5.3, reflecting periodic enhancement in surface productivity. The surface productivity attained its highest level during the Holocene, followed by MIS 3.2 to 2 and then MIS 5.3 to 3.3 with a lowest level. High total organic carbon(TOC) contents, together with high C/N ratios,which stand mostly between 7 and 20, show that the TOC was deposited from mixing sources. Therefore,one has to be cautious to use TOC as a proxy of surface productivity. The high TOC and C/N ratio during MIS 5.1, 3.3 to 3.2 and the Holocene reflect that the terrigenous organic matter input increased during interglacial periods. Increases in the fine-and silt-grained terrigenous components from MIS 5.3 to the middle Holocene imply that with the cooling climate, sea ice on the Bering Sea slope extended continuously. Ice-rafted and charcoal detritus increased during glacial, interstadial and the last deglaciation periods and decreased during interglacial periods,suggesting that sea ice on the slope increased and melted, respectively, during glacial and interglacial periods. The extension of sea ice during glacial periods,which was linked with the climate over the North American Continent, responded to global climate change during late Quaternary glacial and interglacial cycles. |
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