Surface mass balance of the Antarctic Megadune plateau
Environmental Geosciences, Paleoclimate, Ice Core Chemistry
Antarctica holds 27 million km3 of snow and ice that can affect sea level, ocean circulation, and weather patterns. Despite its importance, we lack basic knowledge on snow accumulation in Antarctica, such as how much is accumulating and how it varies over time and space, limiting our capacity to predict the sea level rise. In an attempt to answer these questions multiple ice cores have been drilled in the East Antarctic ice sheet through the East Antarctic International Traverse (EAIIST) projects. These cores come from a previously unsampled region of Antarctica known as the Megadunes for its unusual topography driven by an extreme environment of arid, wind and cold. They are presently stored in France, Italy and Australia. Using volcanic horizons as time markers, coupled with ground penetrating radar (GPR) measurements, we propose to reconstruct the surface mass balance (SMB) of the Megadune plateau, both in time and space. To achieve this goal, I will perform laboratory sampling and analysis of the raw geochemical data of the different ice cores, with capacity of stable isotope and electron microprobe analysis for unambiguous tie-point identification. In a second step, I will treat the GPR data to reveal internal layers of the snow pack. Matching radar internal layers with well-dated ice core reference layers (e.g. volcanic layers) will allow to date and deduce the surface mass balance through time for the full EAIIST transect. The variability of the SMB observed will finally be studied in the context of past and current climate changes.