Next-generation Modeling of Sedimentary Ice-sheet Dynamics

ended

Global sea level changes are grand humanitarian challenges in the 21st century and beyond. The biggest contributor and uncertainty to sea-level projections is dynamical ice-mass loss from the Antarctic Ice Sheet. Fast-moving ice primarily flows by sliding over weak and water-saturated sedimentary deposits that are reshaped into undulations and depositional wedges in the process. Current ice-sheet models do not account for transport of sediment under ice, and commonly assume that basal friction increases if ice flow accelerates. In this project I propose to address these shortcomings by deriving a realistic coupled framework for glacier ice, water and sediment. The sediment model is constrained by laboratory experiments and is coupled to a new model of subglacial hydrology. The ice-water-sediment model is compared to landforms and sedimentary deposits from previous glaciations, as well as contemporary ice sheet flow patterns. The framework allows analysis of climate-perturbation sensitivity, with particular investigation into the dynamical evolution of ice flow and basal environment. By incorporating previously neglected processes, the developed model framework will improve the accuracy of predicted global-mean sea-level change in the future.