- Deborah Verfaillie (Aix Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE, Aix-en-Provence, France)
- Nicolas Champollion (Université Grenoble Alpes, Institut des Géosciences de l’Environnement (IGE), CNRS, Grenoble, France)
- Vincent Favier (Université Grenoble Alpes, Institut des Géosciences de l’Environnement (IGE), CNRS, Grenoble, France)
- Joanna Charton (Aix Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE, Aix-en-Provence, France)
- Vincent Jomelli (Aix Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE, Aix-en-Provence, France)
- Irene Schimmelpfennig (Aix Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE, Aix-en-Provence, France)
- Laurie Menviel (Climate Change Research Centre/ESSRC, The University of New South Wales, Sydney, NSW, Australia)
- Hugues Goosse (Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium)
- Stéphane Blain (Sorbonne Université, CNRS, Laboratoire d'océanographie microbienne (LOMIC), Banyuls sur mer, France)
Understanding the mechanisms of global warming and its impact on human societies is one of the major challenges of the 21st century. In this context, glaciers are excellent indicators of climate because their evolution depends directly on atmospheric conditions through for example temperature and precipitation. Like most of the world's glaciers, sub-Antarctic glaciers are currently undergoing a marked retreat. In the Kerguelen Islands (49° S, 69° E), the Cook Ice Cap has undergone a significant and extremely rapid retreat, losing 20% of its surface area in 40 years, associated with some of the most negative mass balance values observed worldwide.
To better assess the current and future evolution of southern glaciers, it is first necessary to study their past evolution, for which the influence of man is considered negligible. The Kerguelen Islands, due to their geographical location and history, are an exemplary case for understanding past climate mechanisms in the Indian Ocean. Indeed, it harbours well-preserved ancient terrestrial moraines that document the past evolution of glaciers and associated regional climate changes over the last 21,000 years and beyond. Unfortunately, these landforms only provide discontinuous information, both in time and in space. In order to trace the evolution of glaciers over the entire archipelago and the last deglaciation, it is necessary to use glacier-climate modelling.
In this communication, we will present new glacio-climatic simulations of the Cook Ice Cap for the Little Ice Age (~1400-1870 CE) constrained by already-dated moraines around the ice cap. Depending on our progress, simulations for the Antarctic Cold Reversal (∼14,5–12,9 ka) or for the Early-to-Mid-Holocene (~10 to 3 ka) might also be presented, in order to understand the climatic mechanisms at work in this southern region of the Indian Ocean. Simulations for the end of the century will also be discussed to provide insights into the future evolution of the ice cap. The simulations will be carried out using two different but complementary glacier models, allowing us to assess the uncertainties arising from the glaciological models, while the use of different climate inputs will inform us of the uncertainty associated with the global climate models.