Unstable ice stream in Greenland during the Younger Dryas cold event

International audience Past, present, and future ice sheet stability is closely linked to the dynamic behavior of major draining ice streams and surrounding ice shelves. While short observational records document the recent variability and acceleration of ice streams, the long-term dynamics of ice s...

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Published in:Geology
Main Authors: Rinterknecht, Vincent, Jomelli, Vincent, Brunstein, Daniel, Favier, Vincent, Masson-Delmotte, Valérie, Bourlès, Didier, Léanni, Laettitia, Schläppy, Romain
Other Authors: DEES, University of St Andrews Scotland, Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2014
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Online Access:https://hal.science/hal-02905271
https://doi.org/10.1130/G35929.1
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Summary:International audience Past, present, and future ice sheet stability is closely linked to the dynamic behavior of major draining ice streams and surrounding ice shelves. While short observational records document the recent variability and acceleration of ice streams, the long-term dynamics of ice streams remain poorly documented. Here, we date the Pjetursson’s Moraine on Disko Island, Greenland, to 12.2 ± 0.6 ka and demonstrate that the Jakobshavn Isbræ (JI) ice stream collapsed during the middle of the Younger Dryas (YD) cold interval. We suggest that this collapse was due to the incursion of warm subsurface water under the ice shelf fronting the JI ice stream, as well as increased surface-air temperature and sea-surface temperature seasonality starting at the beginning of the YD cold interval. The triggered acceleration of the land-based JI and the delivery of icebergs into Disko Bugt potentially contributed to Heinrich Event 0 at the end of the YD. The collapse of the JI ice stream 12.2 ± 0.6 ka ago demonstrates that calving marine-based ice margins can respond rapidly to environmental changes. It provides a new benchmark for marine-terminating ice stream models.