Bamberg, Audrey; Rosenthal, Yair; Paul, André; Heslop, David; Mulitza, Stefan; Rühlemann, Carsten; Schulz, Michael (2010): (Figure 2) Proxy records of sediment core GeoB6007-2 [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.745950, Supplement to: Bamberg, A et al. (2010): Reduced North Atlantic Central Water formation in response to early Holocene ice-sheet melting. Geophysical Research Letters, 37, L17705, https://doi.org/10.1029/2010GL043878
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Published: 2010-10-06 • DOI registered: 2010-11-04
Abstract:
Central waters of the North Atlantic are fundamental for ventilation of the upper ocean and are also linked to the strength of the Atlantic Meridional Overturning Circulation (AMOC). Here, we show based on benthic foraminiferal Mg/Ca ratios, that during times of enhanced melting from the Laurentide Ice Sheet (LIS) between 9.0-8.5 thousand years before present (ka) the production of central waters weakened the upper AMOC resulting in a cooling over the Northern Hemisphere. Centered at 8.54 ± 0.2 ka and 8.24 ± 0.1 ka our dataset records two ~150-year cooling events in response to the drainage of Lake Agassiz/Ojibway, indicating early slow-down of the upper AMOC in response to the initial freshwater flux into the subpolar gyre (SPG) followed by a more severe weakening of both the upper and lower branches of the AMOC at 8.2 ka. These results highlight the sensitivity of regional North Atlantic climate change to the strength of central-water overturning and exemplify the impact of both gradual and abrupt freshwater fluxes on eastern SPG surface water convection. In light of the possible future increase in Greenland Ice Sheet melting due to global warming these findings may help us to better constrain and possibly predict future North Atlantic climate change.
Project(s):
Funding:
German Research Foundation (DFG), grant/award no. 25575884: Integrierte Analyse zwischeneiszeitlicher Klimadynamik
Coverage:
Latitude: 30.850000 * Longitude: -10.268300
Date/Time Start: 1999-10-18T15:50:00 * Date/Time End: 1999-10-18T15:50:00
Event(s):
GeoB6007-2 * Latitude: 30.850000 * Longitude: -10.268300 * Date/Time: 1999-10-18T15:50:00 * Elevation: -900.0 m * Recovery: 11.05 m * Campaign: M45/5a * Basis: Meteor (1986) * Method/Device: Gravity corer (Kiel type) (SL)
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
2 datasets
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Datasets listed in this publication series
- Bamberg, A; Rosenthal, Y; Paul, A et al. (2010): (Figure 2) Stable oxygen isotopes, Mg/Ca ratios, and intermediate-water temperatures of sediment core GeoB6007-2. https://doi.org/10.1594/PANGAEA.745947
- Bamberg, A; Rosenthal, Y; Paul, A et al. (2010): (Figure 2) Carbon isotopes of sediment core GeoB6007-2. https://doi.org/10.1594/PANGAEA.745949