EGU2020-1296, updated on 12 Jun 2020
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Investigating basal thaw as a potential driver of ice flow acceleration in Antarctica

Eliza Dawson1, Dustin Schroeder1,2, Winnie Chu1, Elisa Mantelli3, and Helene Seroussi4
Eliza Dawson et al.
  • 1Dept. of Geophysics, Stanford University
  • 2Dept. of Electrical Engineering, Stanford University
  • 3Atmospheric and Oceanic Sciences Program, Princeton University
  • 4NASA Jet Propulsion Lab

Glacial thermal processes exert a fundamental control on ice flow, governing viscosity and frozen-to-thawed transitions at the ice-bed interface. Across Antarctica, frozen bed regions characterized by numerical models and geophysical observations, can also reduce ice flow by increasing basal traction. Some frozen bed regions can separate or confine fast-flowing glaciers and ice streams. Others separate inland catchments with thawed beds from the grounding zone of marine ice-sheet sectors. If regions with frozen bed experienced thawing, such a transition may lead to ice-sheet acceleration, reconfiguration, or retreat. To investigate the potential impact of such a thermal transition, we use the JPL/UCI Ice Sheet System Model (ISSM) to identify vulnerable regions across Antarctica that are close to the basal melting point. We assess the impact of thawing these regions by quantifying resulting volume changes and surface expressions. This allows us to identify the areas of the ice sheet where the thermal regime at the ice-bed interface has the largest potential impact on ice-sheet stability and sea-level contribution. We also examine the potential basal temperature and thaw-propagation thresholds governing this process. We then compare the ISSM results to a selection of ice-penetrating radar sounding observations to refine our constraints of the configuration, distribution, and extent of these thermally critical areas.

How to cite: Dawson, E., Schroeder, D., Chu, W., Mantelli, E., and Seroussi, H.: Investigating basal thaw as a potential driver of ice flow acceleration in Antarctica, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1296,, 2019

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Presentation version 2 – uploaded on 04 May 2020
Small revisions to poster text
  • CC1: Comment on EGU2020-1296, Martin Ross, 05 May 2020

    Nice work Eliza! I'm not a modeler, but I'm interested in understanding thermal transitions and thermomechanical feedback on ice sheet reconfiguration, especially for the Laurentide Ice Sheet. I'll be following this research!  

Presentation version 1 – uploaded on 02 May 2020 , no comments