Geologic data provide crucial insights into Antarctic Ice Sheet dynamics. For example, glacial landforms imprinted on the seafloor mark the ‘footprint’ of marine-based ice sheets larger than today. On land, progressive exposure of mountain peaks emerging from the ice sheet reveal past ice elevation changes. My research analyzes geologic datasets and uses numerical ice sheet simulations to link these marine and terrestrial geologic records in space and time to make larger-scale inferences about continent-wide ice sheet evolution.
During the Last Glacial Maximum, ~20,000 years ago, the Antarctic Ice Sheet was much larger and thicker than today, and extended to the continental shelf break in many places before receding to the modern configuration. Glacial landforms and sediments associated with ice advance and retreat are preserved on the seafloor. These features tell us that within the Ross Sea, ice-sheet retreat was influenced by regional topography and seafloor geology (Halberstadt et al., 2016), as well as subglacial meltwater (Simkins et al., 2017) and properties of the unconsolidated sediment underlying ice streams (Halberstadt et al., 2018).
Read more about Ross Sea deglacial dynamics reconstructed from geologic data:
NSF OPP Postdoctoral Research Fellowship: High-resolution nested Antarctic Ice Sheet modeling to reconcile marine and terrestrial geologic data
This work integrates both marine and terrestrial geologic datasets with numerical simulations to investigate Antarctic Ice Sheet behavior (and contribution to global sea level) throughout the last deglaciation, ~20,000 years ago until present. Specifically, this research will address two issues regarding the relationship between simulations and data and their use in reconstructing past ice-sheet behavior:
Comparison between model simulations and exposure age data is improved through high-resolution nested ice sheet modeling, which provides unprecedented context for exposure age data generally located in regions of complex topography.