Last Glacial Maximum to Holocene sea surface conditions at Umnak Plateau, Bering Sea, as inferred from diatom, alkenone, and stable isotope records

被引:109
作者
Caissie, Beth E. [1 ]
Brigham-Grette, Julie [1 ]
Lawrence, Kira T. [4 ]
Herbert, Timothy D. [3 ]
Cook, Mea S. [2 ]
机构
[1] Univ Massachusetts, Dept Geosci, Amherst, MA 01301 USA
[2] Williams Coll, Dept Geosci, Williamstown, MA 01267 USA
[3] Brown Univ, Dept Geol Sci, Providence, RI 02912 USA
[4] Lafayette Coll, Dept Geol & Environm Geosci, Easton, PA 18042 USA
来源
PALEOCEANOGRAPHY | 2010年 / 25卷
基金
美国国家科学基金会;
关键词
DINOFLAGELLATE CYST ASSEMBLAGES; NORTH PACIFIC-OCEAN; OKHOTSK SEA; BIOMARKER APPROACH; LATE PLEISTOCENE; AGE CALIBRATION; CLIMATE-CHANGE; DATA-BASE; DEEP-SEA; ICE;
D O I
10.1029/2008PA001671
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
The Bering Sea gateway between the Pacific and Arctic oceans impacts global climate when glacial-interglacial shifts in shore line position and ice coverage change regional albedo. Previous work has shown that during the last glacial termination and into the Holocene, sea level rises and sea ice coverage diminishes from perennial to absent. Yet, existing work has not quantified sea ice duration or sea surface temperatures (SST) during this transition. Here we combine diatom assemblages with the first alkenone record from the Bering Sea to provide a semiquantitative record of sea ice duration, SST, and productivity change since the Last Glacial Maximum (LGM). During the LGM, diatom assemblages indicate that sea ice covered the southeastern Bering Sea perennially. At 15.1 cal ka B. P., the diatom assemblage shifts to one more characteristic of seasonal sea ice and alkenones occur in the sediments in low concentrations. Deglaciation is characterized by laminated intervals with highly productive and diverse diatom assemblages and inferred high coccolithophorid production. At 11.3 cal ka B. P. the diatom assemblage shifts from one dominated by sea ice species to one dominated by a warmer water, North Pacific species. Simultaneously, the SST increases by 3 degrees C and the southeastern Bering Sea becomes ice-free year-round. Productivity and temperature proxies are positively correlated with independently dated records from elsewhere in the Bering Sea, the Sea of Okhotsk, and the North Pacific, indicating that productivity and SST changes are coeval across the region.
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页数:16
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