Evolution of a debris-covered glacier in the Kerguelen Archipelago (49°S, 69°E) over the past 15,000 years constrained by in situ cosmogenic 36Cl dating
- 1Aix Marseille Univ., CNRS, IRD, INRAE, Coll France, UM 34 CEREGE, Aix-en-Provence, France (charton@cerege.fr)
- 2Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgique
- 3Université Grenoble Alpes, IGE, CNRS, Grenoble, France
- 4Université Université Paris 1 Panthéon-Sorbonne, CNRS Laboratoire de Géographie Physique, 92195 Meudon, France
- 5ASTER Team
Debris-covered glaciers constitute a substantial part of the worldwide cryosphere (Scherler et al. 2018). However, their long-term response to multi-millennial climate variability has rarely been studied, in particular in the Southern Hemisphere. The presence of both debris-covered and debris-free glaciers on Kerguelen Archipelago (49°S, 69°E) offers therefore an excellent opportunity to investigate and compare long-term evolution of these two types of glaciers. To do so, we used the cosmogenic 36Cl surface dating method on moraine boulders that allows to establish temporal constraints of glacier oscillation. We provide here the first Late Glacial and Holocene glacier chronology of a still active debris-covered glacier from the archipelago: the Gentil Glacier. Results show that the Gentil Glacier advanced once at ~14.3 ka, i.e. during the Late Glacial (19.0 – 11.6 ka), and re-advanced during the Late Holocene at ~2.6 ka (Charton et al., 2020). Both debris-covered and debris-free glaciers experienced a broadly synchronous advance during the Late Glacial, that may be assigned to the Antarctic Cold Reversal event (14.5 – 12.9 ka) (Jomelli et al., 2017; 2018). This suggests that both types (debris-covered and debris-free) of glaciers at Kerguelen were sensitive to large amplitude temperature fluctuations recorded in Antarctic ice cores (WAIS divide Project Members, 2013), associated with increased precipitations (Van der Putten, 2015). However, during the Late Holocene, the advance at about ~2.6 ka was not observed on other glaciers and seems to be a specific response of the debris-covered Gentil Glacier, either related to distinct ice dynamics or an individual response to precipitation changes.
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How to cite: Jomelli, V., Charton, J., Schimmelpfennig, I., Verfaillie, D., Favier, V., Mokadem, F., Gilbert, A., Brun, F., Aumaître, G., Bourlès, D. L., and Keddadouche, K.: Evolution of a debris-covered glacier in the Kerguelen Archipelago (49°S, 69°E) over the past 15,000 years constrained by in situ cosmogenic 36Cl dating, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13304, https://doi.org/10.5194/egusphere-egu21-13304, 2021.
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