Linking the 8.2 ka event and its freshwater forcing in the Labrador Sea

Type Article
Date 2012-09
Language English
Author(s) Hoffman Jeremy S.2, Carlson Anders E.1, 3, Winsor Kelsey1, Klinkhammer Gary P.4, Legrande Allegra N.5, 6, Andrews John T.7, 8, Strasser Jeffrey C.2
Affiliation(s) 1 : Univ Wisconsin, Dept Geosci, Madison, WI 53706 USA.
2 : Augustana Coll, Dept Geol, Rock Isl, IL 61201 USA.
3 : Univ Wisconsin, Ctr Climat Res, Madison, WI 53706 USA.
4 : Oregon State Univ, Coll Earth Ocean & Atmospher Sci, Corvallis, OR 97331 USA.
5 : Columbia Univ, Ctr Climate Syst Res, New York, NY USA.
6 : NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
7 : Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA.
8 : Univ Colorado, Inst Arctic & Alpine Res, Boulder, CO 80309 USA.
Source Geophysical Research Letters (0094-8276) (Amer Geophysical Union), 2012-09 , Vol. 39 , N. 18 , P. L18703 (5p.)
DOI 10.1029/2012GL053047
WOS© Times Cited 49
Abstract

The 8.2 ka event was the last deglacial abrupt climate event. A reduction in the Atlantic meridional overturning circulation (AMOC) attributed to the drainage of glacial Lake Agassiz may have caused the event, but the freshwater signature of Lake Agassiz discharge has yet to be identified in delta O-18 of foraminiferal calcite records from the Labrador Sea, calling into question the connection between freshwater discharge to the North Atlantic and AMOC strength. Using Mg/Ca-paleothermometry, we demonstrate that similar to 3 degrees C of near-surface ocean cooling masked an similar to 1.0 parts per thousand decrease in western Labrador Sea delta O-18 of seawater concurrent with Lake Agassiz drainage. Comparison with North Atlantic delta O-18 of seawater records shows that the freshwater discharge was transported to regions of deep-water formation where it could perturb AMOC and force the 8.2 ka event.

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Publisher's official version 5 823 KB Open access
Correction 1 265 KB Open access
readme.txt 3 KB Open access
Text S1. Detailed description of the core site and methodology. 22 KB Open access
Figure S1. Hydrography of core site HU87033‐017. 1 160 KB Open access
Table S1. 14C dates used for HU87033‐017. 303 bytes Open access
Table S2. HU87033‐017 percent sand and calcification temperature. 1 KB Open access
Table S3. HU87033‐017 averageδ18Oswat 100‐year resolution. 537 bytes Open access
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How to cite 

Hoffman Jeremy S., Carlson Anders E., Winsor Kelsey, Klinkhammer Gary P., Legrande Allegra N., Andrews John T., Strasser Jeffrey C. (2012). Linking the 8.2 ka event and its freshwater forcing in the Labrador Sea. Geophysical Research Letters, 39(18), L18703 (5p.). Publisher's official version : https://doi.org/10.1029/2012GL053047 , Open Access version : https://archimer.ifremer.fr/doc/00496/60740/