Active North Atlantic deepwater formation during Heinrich Stadial 1

• Published in: Quaternary Science Reviews
• Main Authors: Repschläger, Janne, Zhao, Ning, Rand, Devin, Lisiecki, Lorraine, Muglia, Juan, Mulitza, Stefan, Schmittner, Andreas, Cartapanis, Olivier, Bauch, Henning, A, Schiebel, Ralf, Haug, Gerald, H
• Other Authors: Max Planck Institute for Chemistry (MPIC), Max-Planck-Gesellschaft, University of California (UC), Centro para el Estudio de Sistemas Marinos (CESIMAR/CENPAT-CONICET) (CESIMAR), University of Bremen, College of Earth, Ocean and Atmospheric Sciences Corvallis (CEOAS), Oregon State University (OSU), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Alfred Wegener Institute Potsdam, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung = Alfred Wegener Institute for Polar and Marine Research = Institut Alfred-Wegener pour la recherche polaire et marine (AWI), Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: Quaternary; Paleoceanography; North Atlantic; Data compilation stable isotopes; [SDE.MCG]Environmental Sciences/Global Changes; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology; [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy; Iceland
• Online Access: https://hal.science/hal-03541822; https://hal.science/hal-03541822/document; https://hal.science/hal-03541822/file/1-s2.0-S0277379121003528-main-2.pdf; https://doi.org/10.1016/j.quascirev.2021.107145

International audience Deepwater circulation significantly changed during the last deglaciation from a shallow to a deepreaching overturning cell. This change went along with a drawdown of isotopically light waters into the abyss and a deep ocean warming that changed deep ocean stratification from a salinity-to a temperature-controlled mode. Yet, the exact mechanisms causing these changes are still unknown. Furthermore, the long-standing idea of a complete shutdown of North Atlantic deepwater formation during Heinrich Stadial 1 (HS1) (17.5e14.6 kyr BP) remains prevalent. Here, we present a new compilation of benthic d 13 C and d 18 O data from the North Atlantic at high temporal resolution with consistent age models, established as part of the international PAGES working group OC3, to investigate deepwater properties in the North Atlantic. The extensive compilation, which includes 105 sediment cores, reveals different water masses during HS1. A water mass with heavy d 13 C and d 18 O signature occupies the Iceland Basin, whereas between 20 and 50 N, a distinct tongue of 18 O depleted, 13 C enriched water reaches down to 4000 m water depths. The heavy d 13 C signature indicates active deepwater formation in the North Atlantic during HS1. Differences in its d 18 O signature indicate either different sources or an alteration of the deepwater on its southward pathway. Based on these results, we discuss concepts of deepwater formation in the North Atlantic that help to explain the deglacial change from a salinity-driven to a temperature-driven circulation mode.