EGUsphere EGUsphere EGUsphere EGUsphere Copernicus Publications Göttingen, Germany 10.5194/egusphere-2026-5815 Towards bridging the gap between Antarctic subglacial boundary conditions and ice-sheet model parameterization MacKie Emma J. https://orcid.org/0000-0002-6303-5249 1 Li Lu https://orcid.org/0000-0001-6165-2828 2 3 4 Halberstadt Anna Ruth W. https://orcid.org/0000-0003-2582-7074 5 Jamieson Stewart S. R. 6 Law Robert https://orcid.org/0000-0003-0067-5537 7 Lowe Maximilian https://orcid.org/0000-0002-0313-4253 8 9 McCormack Felicity S. https://orcid.org/0000-0002-2324-2120 10 Paxman Guy J. G. https://orcid.org/0000-0003-1787-7442 6 Aitken Alan R. A. https://orcid.org/0000-0002-6375-2504 2 3 Dawson Eliza 11 Ely Jeremy https://orcid.org/0000-0003-4007-1500 7 Field Michael https://orcid.org/0009-0008-4044-1755 1 Halpin Jacqueline A. https://orcid.org/0000-0002-4992-8681 3 12 Hansen Dougal 13 Martos Yasmina M. 14 15 Nowicki Sophie https://orcid.org/0000-0001-6328-5590 16 Reading Anya https://orcid.org/0000-0002-9316-7605 3 17 Shao Niya 1 Stål Tobias https://orcid.org/0000-0002-4323-6748 3 17 Tinto Kirsty J. 18 Venturelli Ryan https://orcid.org/0000-0001-9548-0382 19 Department of Geological Sciences, University of Florida, Gainesville, FL, 32611, USA School of Earth and Oceans, The University of Western Australia, Perth, Western Australia, 6009, Australia Australian Centre for Excellence in Antarctic Science Mineral Resources, Commonwealth Scientific and Industrial Research Organisation, Kensington, Western Australia, 6151, Australia Department of Earth and Planetary Sciences, University of Texas at Austin, Austin, TX, 78712, USA Department of Geography, Durham University, Durham, DH1 3LE, UK School of Geography and Planning, University of Sheffield, S10 2TN, UK Institute of Geosciences, Kiel University, Kiel, 24118, Germany British Antarctic Survey, Cambridge, CB3 0ET, UK Securing Antarctica’s Environmental Future, School of Earth, Atmosphere and Environment, Monash University, Kulin Nation, Victoria, 3800, Australia Georgia Institute of Technology, School of Earth and Atmospheric Sciences, Atlanta, GA, 30332, USA Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7004, Australia Department of Earth, Environmental, and Planetary Sciences, Washington University, St. Louis, MO, 63130, USA NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA Department of Astronomy, University of Maryland, College Park, MD, 20742, USA Department of Earth Sciences, University at Buffalo, Buffalo, NY, 14260, USA School of Natural Sciences, Physics, University of Tasmania, Hobart, Tasmania, 7001, Australia Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, 10964, USA School of Earth, Space and Planets, Colorado School of Mines, Golden, CO, 80401, USA 03 11 2026 2026 1 60 Copyright: © 2026 Emma J. MacKie et al. 2026 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-5815/ The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-5815/egusphere-2026-5815.pdf

The geology of Antarctica exerts a first-order control on ice-sheet dynamics by shaping the subglacial landscape and regulating basal friction, thermal profile, hydrology, and sediment distribution. These bed conditions influence where ice flows, how fast it moves, and how it responds to a changing climate. Yet most ice-sheet models incorporate geologic information only indirectly, typically as smoothed topography and simplified representations of basal processes. This incomplete capturing of geological information in ice-sheet models can be attributed to observational gaps, an incomplete community understanding of subglacial processes, and the need to simplify processes in ice-sheet models. As such, there is an opportunity to enhance communication and translation between geology and modeling disciplines, which will help improve our understanding of the thresholds and instabilities in Antarctic ice-sheet dynamics. Here, we discuss key subglacial geological conditions and processes and how they are used (or not used) in ice-sheet models. We highlight the disconnect between geological and physical interpretations of subglacial conditions and discuss possible strategies that will help bridge the gap between these disciplines as part of investigations of changing ice-sheet behavior.

 National Science Foundation 2324092 National Science Foundation 2002346 Australian Research Council SR200100008 Australian Research Council DP250101122 Australian Research Council SR200100005