Speaker: Lindsay Prothro, Geology program, Texas A&M Corpus Chrsiti
Title: Grounding Zone Processes at the Limits of Marine Ice Sheet Stability
Host: Benjamin Keisling
Abstract: Marine-based ice sheets are particularly sensitive to environmental change, yet the processes governing their contemporary retreat remain difficult to constrain. The grounding zone, where grounded ice transitions to a floating ice shelf, is a critical part of this system. Here, ice dynamics evolve with oceanographic forcings and sediment transport processes to regulate ice sheet stability.
In this talk, I present sedimentological, geophysical, and micropaleontological observations from the Antarctic continental shelf that capture the evolution of grounding zone processes during past ice sheet retreat, from full ice sheet expansion to the last vestiges of ice shelves pinned to shallow submarine banks. At both early and late stages of retreat, ice sheets are subject to distinct, yet equally significant sources of instability, each with their own geomorphological or sedimentological signatures. These observations provide a framework for interpreting grounding zone behavior and its role in marine ice sheet stability across a range of timescales.