(Table S1) Age determination of sediment core OCE326-GGC5

The Atlantic meridional overturning circulation is widely believed to affect climate. Changes in ocean circulation have been inferred from records of the deep water chemical composition derived from sedimentary nutrient proxies (Boyle and Keigwin, 1987, doi:10.1038/330035a0), but their impact on cli...

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Bibliographic Details
Main Authors: McManus, Jerry F, Francois, Roger, Gherardi, Jeanne-Marie, Keigwin, Lloyd D, Brown Leger, Susan
Format: Dataset
Language:English
Published: PANGAEA 2004
Subjects:
Age
14C AMS
14C calibrated
CALIB 4.3 (Stuiver et al.
1998)
dated
dated material
dated standard deviation
Calendar age
DEPTH
sediment/rock
GC
GGC5
Gravity corer
North Atlantic
OCE326-GGC5
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.769839
https://doi.org/10.1594/PANGAEA.769839
Description
Summary:The Atlantic meridional overturning circulation is widely believed to affect climate. Changes in ocean circulation have been inferred from records of the deep water chemical composition derived from sedimentary nutrient proxies (Boyle and Keigwin, 1987, doi:10.1038/330035a0), but their impact on climate is difficult to assess because such reconstructions provide insufficient constraints on the rate of overturning (LeGrand and Wunsch, 1995, doi:10.1029/95PA01455). Here we report measurements of 231Pa/230Th, a kinematic proxy for the meridional overturning circulation, in a sediment core from the subtropical North Atlantic Ocean. We find that the meridional overturning was nearly, or completely, eliminated during the coldest deglacial interval in the North Atlantic region, beginning with the catastrophic iceberg discharge Heinrich event H1, 17,500 yr ago, and declined sharply but briefly into the Younger Dryas cold event, about 12,700 yr ago. Following these cold events, the 231Pa/230Th record indicates that rapid accelerations of the meridional overturning circulation were concurrent with the two strongest regional warming events during deglaciation. These results confirm the significance of variations in the rate of the Atlantic meridional overturning circulation for abrupt climate changes.

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