A debris-covered glacier at Kerguelen (49°S, 69°E) over the past 15 000 years

• Published in: Antarctic Science
• Main Authors: Charton, Joanna, Jomelli, Vincent, Schimmelpfennig, Irene, Verfaillie, Deborah, Favier, Vincent, Mokadem, Fatima, Gilbert, Adrien, Brun, Fanny, Aumaitre, Georges, Bourlès, Didier, Keddadouche, Karim
• Other Authors: Université Paris 1 Panthéon-Sorbonne (UP1), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Université Catholique de Louvain = Catholic University of Louvain (UCL), Université Grenoble Alpes (UGA), French INSU LEFE Glacepreker project, IPEV Kesaaco 1048 project, ANR-11-LABX-0046,Dynamite,Dynamiques Territoriales et spatiales(2011)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: glacier fluctuations; in situ cosmogenic chlorine-36 dating; paleoclimate; Antarctic Cold Reversal; Holocene; sub-Antarctic; [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; Antarctic; Kerguelen; The Antarctic; Antarc*; Antarctic Science
• Online Access: https://hal.archives-ouvertes.fr/hal-02988434; https://hal.archives-ouvertes.fr/hal-02988434/document; https://hal.archives-ouvertes.fr/hal-02988434/file/Charton%20et%20al.%202020%20preprint.pdf; https://doi.org/10.1017/S0954102020000541

International audience Debris-covered glaciers constitute a large part of the world's cryosphere. However, little is known about their long-term response to multi-millennial climate variability, in particular in the Southern Hemisphere. Here, we provide first insights into the response of a debris-covered glacier to multi-millennial climate variability in the sub-Antarctic Kerguelen Archipelago, which can be compared to that of recently investigated debris-free glaciers. We focus on the Gentil Glacier and present thirteen new 36 Cl cosmic-ray exposure ages from moraine boulders. The Gentil Glacier experienced at least two glacial advancesthe first one during the Late Glacial (19.0-11.6 ka) at ~14.3 ka and the second one during the Late Holocene at ~2.6 ka. Both debris-covered and debris-free glaciers advanced broadly synchronously during the Late Glacial, most probably during the Antarctic Cold Reversal event (14.5-12.9 ka). This suggests that both glacier types at Kerguelen were sensitive to abrupt temperature changes recorded in Antarctic ice cores, associated with increased moisture. However, during the late Holocene, the advance at about ~2.6 ka was not observed in other glaciers and seems to be an original feature of the debris-covered Gentil Glacier, either related to distinct dynamics or distinct sensitivity to precipitation changes.