Deglacial Ice Sheet Instabilities Induced by Proglacial Lakes

• Published in: Geophysical Research Letters
• Main Authors: Quiquet, Aurélien, Dumas, Christophe, Paillard, Didier, Ramstein, Gilles, Ritz, Catherine, Roche, Didier M.
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Modélisation du climat (CLIM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Antarctic; Antarc*; Ice Sheet
• Online Access: https://hal.science/hal-03228350; https://hal.science/hal-03228350/document; https://hal.science/hal-03228350/file/2020GL092141.pdf; https://doi.org/10.1029/2020GL092141

International audience During the last deglaciation (21–7 kaBP), the gradual retreat of Northern Hemisphere ice sheet margins produced large proglacial lakes. While the climatic impacts of these lakes have been widely acknowledged, their role on ice sheet grounding line dynamics has received very little attention so far. Here, we show that proglacial lakes had dramatic implications for the North American ice sheet dynamics through a self‐sustained mechanical instability which has similarities with the known marine ice sheet instability consequently providing fast retreat of large portions of the ice sheet over the continent. This instability mechanism is likely important in contributing to deglaciation of terrestrial glaciers and ice sheets with proglacial lakes at their margins as it can substantially accelerate the mass loss. Echoing our knowledge of Antarctic ice sheet dynamics, proglacial lakes are another manifestation of the importance of grounding line dynamics for ice sheet evolution.