EAPS

Title: Marine ice sheet dynamics

Abstract: Marine ice sheets are continental-scale masses of glacier ice that rest on beds that lie below sea level. Because ice floats, this configuration is susceptible to a buoyancy-driven instability, known as the marine ice sheet instability, that can lead to rapid discharge of grounded ice to the ocean and high rates of sea level rise. This potential for collapse makes the West Antarctic Ice Sheet—the only extant marine ice sheet—the largest source of uncertainty in future sea level rise and a key player in abrupt changes in past sea level. Constraining the past and forecasting the future behavior of marine ice sheets is challenging because of the complex rheology of glacier ice and interactions between the ice sheets, oceans, atmosphere, and the solid earth. These factors help drive rich dynamical behavior that has only recently been brought into greater focus through improved observations and an increasingly sophisticated understanding of glacier mechanics. In this talk, I will give a broad introduction to marine ice sheet dynamics followed by a more focused discussion on the mechanics of lateral shear margins and ice-shelf buttressing, two of the most important resistances to ice flow that have the potential to reshape our understanding of marine ice sheet behavior and sea level rise.