Tropical-Subpolar Linkages in the North Atlantic during the last Glacial Period
Abstract
We studied millennial-scale changes in planktonic foraminifera assemblages from the last glacial period in a high-resolution core (KN166-14-JPC13) recovered from the southern part of the Gardar Drift in the subpolar North Atlantic. Similar to recent findings reported by Jonkers et al. (2010), we also found that the sub-polar North Atlantic Ocean experienced some seasonal warming during each of the Heinrich Events (HEs). In addition, increasing abundances of tropical species are found just prior to the IRD event marking the end of each Bond cycle, suggesting that summer warming may have been involved in triggering Heinrich events. We suggest that tropical-subtropical water transported via the Gulf Stream and North Atlantic Drift may have triggered the collapse of large NH ice-shelves. Sharp decreases in polar species are tied to abrupt warming following Heinrich Events as documented in Greenland Ice cores and other marine records in the North Atlantic. The record bears a strong resemblance to the tropical record of Cariaco basin (Peterson et al., 2000), suggesting strong tropical-subpolar linkages in the glacial North Atlantic. Enhanced spring productivity, possibly related to eddy activity along the Subpolar Front, is recorded by increased shell size, high δ13C in G. bulloides and other biological indices early during the transition from HE stadials to the following interstadial.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFMPP13B1512V
- Keywords:
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- 4900 PALEOCEANOGRAPHY;
- 4901 PALEOCEANOGRAPHY / Abrupt/rapid climate change;
- 4944 PALEOCEANOGRAPHY / Micropaleontology;
- 4954 PALEOCEANOGRAPHY / Sea surface temperature