
Department Seminar: Tyler Pelle
Title: Investigating the future evolution of vulnerable Antarctic basins using coupled ice sheet and subglacial hydrology modeling
Abstract: Subglacial freshwater is known to exist widespread beneath the Antarctic Ice Sheet and can impact ice flow via two main mechanisms: (1) subglacial water can reduce the frictional drag that opposes grounded ice sliding; (2) subglacial water that discharges across the grounding line and into sub-ice shelf ocean cavities can locally enhance ice shelf melt near deep grounding line points. To quantify the relative contributions of these coupled forcing processes to mass loss and retreat of vulnerable Antarctic subglacial basins, we develop a coupled ice sheet/shelf and subglacial hydrology modeling framework and use it to project the future evolution of the Aurora Subglacial Basin (ASB) and Amundsen Sea Embayment (ASE) in East and West Antarctica, respectively. In both basins, the coupled ice-hydrology interactions resolved here accelerate grounding line retreat of major outlet glaciers by up to 30 years and enhance the global sea level contribution of these sectors by up to 30%; however, the relative roles of the two ice-hydrology interaction processes in driving this enhanced retreat and mass loss differ substantially between basins and climate forcing scenarios. The results presented here demonstrate the importance of resolving ice-hydrology interactions in future projections of the Antarctic Ice Sheet and that future Antarctic sea level assessments that do not take these interactions into account might be severely underestimating ice sheet mass loss.