Safety Bands of Thwaites Glacier

Mass loss from the Antarctic Ice Sheet is the main source of uncertainty in projections of future sea-level rise. These uncertainties essentially stem from the fact that some regions, such as Thwaites Glacier, may reach a tipping point, defined as irreversible mass loss on human time scales, with a warming climate. The exact timing of when these tipping points may occur remains difficult to determine, allowing for a large divergence in timing of onset and mass loss in model projections. Previous studies have emphasized the difficulties assessing the most suitable observable and the record length necessary to predict such an abrupt collapse within the Early Warning Indicators (EWI) framework. In particular, Rosier et al. (2021) showed that EWI robustly detect the onset of the marine ice sheet instability in realistic geometries such as Pine Island Glacier. The goal of this work is to determine the physical processes that influence the rate of grounding-line retreat of Thwaites Glacier and to test the capability of EWI to predict the onset of such a collapse. Ultimately, this study aims at mapping potential safety bands of grounding-line positions where the glacier may still recover or alternatively reach a ‘stable’ state.