Sedimentological and geochemical records of the North Atlantic Glacial Eastern Boundary Current, 50-15 ka BP

Date 2020-12
Temporal extent 2021
Author(s) Toucanne SamuelORCID1, Soulet GuillaumeORCID1, Vazquez Riveiros NataliaORCID1, Boswell Steven2, Dennielou BernardORCID1, Waelbroeck ClaireORCID3, Bayon Germain1, Mojtahid MeryemORCID4, Bosq Mathieu5, Sabine Marjolaine6, Zaragosi Sébastien6, Bourillet Jean-FrancoisORCID1, Mercier HerleORCID7
Affiliation(s) 1 : IFREMER, Unité de Recherche Géosciences Marines, Laboratoire Géophysique et enregistrement Sédimentaire, CS10070, F-29280 Plouzané, France
2 : Columbia University, Lamont-Doherty Earth Observatory, Palisades, New York 10964, United States
3 : CNRS, Laboratoire d’Océanographie et du Climat : Expérimentation et Approches Numériques, LOCEAN/IPSL, Sorbonne Université-CNRS-IRD-MNHN, UMR7159, Paris, France
4 : Université d’Angers, LPG-BIAF UMR-CNRS 6112, UFR Sciences, 2 bd Lavoisier 49045, Angers Cedex 01, France
5 : Université Bordeaux, PACEA, UMR 5199 CNRS - Bâtiment B8, allée Geoffroy Saint Hilaire, 33615 Pessac, France
6 : Université Bordeaux, UMR-CNRS 5805 EPOC - OASU, CS50023, 33615 Pessac, France
7 : CNRS, IFREMER, Université de Brest, IRD, Laboratoire d’Océanographie Physique et Spatiale (LOPS), Centre IFREMER de Bretagne, CS10070, F-29280, Plouzané, France
DOI 10.17882/77667
Publisher SEANOE
Note This dataset is based on the study of cores MD95-2002, MD99-2328, CBT-CS10, BOBGEO-CS03, GIT-CS02, BOBGEO-CS05 and MD04-2842.
Keyword(s) AMOC, last glacial period, Dansgaard-Oeschger, paleoclimate, paleoceanography, eastern boundary current, European Slope Current, contourites
Abstract

The upper branch of the Atlantic Meridional Overturning Circulation (AMOC) plays a critical role in ocean circulation and climate change, yet its variability during the last glacial period is poorly documented. Here, we investigate the northward-flowing Glacial Eastern Boundary Current (GEBC) in the North Atlantic, known today as the European Slope Current, and representing the easternmost portion of the upper branch of the AMOC. Based on flow speed (sortable silt, XRF) and radiogenic/stable isotopic records, we show that Dansgaard-Oeschger (D/O) interstadials (stadials) correspond to a faster (weaker) GEBC during the ~50-15 ka period. This, by analogy to present-day conditions, suggests enhanced (reduced) strength of the subpolar gyre and, by extension, of northern-sourced water production and AMOC during D-O interstadials (stadials). Concomitant fluctuations of both the European Ice Sheet and the GEBC between ~30 and 17 ka suggest an active role of the upper branch of AMOC in the poleward transport of heat and freshwater to the northern North Atlantic, with direct impacts on deep water formation and AMOC strength. Our GEBC reconstruction is the first physical (non-chemical) record documenting dynamic upper AMOC variability at high resolution in the eastern basin of the North Atlantic. Together with the deep North Atlantic records of northern-sourced water export, they confirm the central role of the AMOC in the generation of abrupt climate changes.

Licence CC-BY
Acknowledgments The production of this dataset and associated publication was sponsored by the French National Research Agency (ANR) via the LabexMER program (ANR-10-LABX-19-01) and the TANDEM project (ANR-11-RSNR-00023-01). The authors warmly acknowledge the crew of oceanographic cruises ALIENOR 2 (https://doi.org/10.17600/4200200), BOBGEO (https://doi.org/10.17600/9030060), CABTEX (https://doi.org/10.17600/10030050), GITAN (https://doi.org/10.17600/15017800), IMAGES1 (https://doi.org/10.17600/95200110), IMAGESV-MD114 (https://doi.org/10.17600/99200070).
Data
File Size Format Processing Access
Radiogenic neodymium isotopic composition (planktic foraminifera), French Atlantic margin 17 KB XLS, XLSX Processed data Open access
Stable Carbon/Oxygen isotopic composition (benthic foraminifera), French Atlantic margin 44 KB XLS, XLSX Processed data Open access
Sortable silt and XRF log (Zr/Rb), French Atlantic margin 262 KB XLS, XLSX Processed data Open access
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How to cite 

Toucanne Samuel, Soulet Guillaume, Vazquez Riveiros Natalia, Boswell Steven, Dennielou Bernard, Waelbroeck Claire, Bayon Germain, Mojtahid Meryem, Bosq Mathieu, Sabine Marjolaine, Zaragosi Sébastien, Bourillet Jean-Francois, Mercier Herle (2020). Sedimentological and geochemical records of the North Atlantic Glacial Eastern Boundary Current, 50-15 ka BP. SEANOE. https://doi.org/10.17882/77667


In addition to properly cite this dataset, it would be appreciated that the following work(s) be cited too, when using this dataset in a publication :


Toucanne Samuel, Soulet Guillaume, Vazquez Riveiros Natalia, Boswell Steven M., Dennielou Bernard, Waelbroeck Claire, Bayon Germain, Mojtahid Meryem, Bosq Mathieu, Sabine Marjolaine, Zaragosi Sébastien, Bourillet Jean-Francois, Mercier Herle (2021). The North Atlantic Glacial Eastern Boundary Current as a key driver for ice‐sheet – AMOC interactions and climate instability. Paleoceanography And Paleoclimatology, 36(3), e2020PA004068 (23p.). https://doi.org/10.1029/2020PA004068