Ehrenfeucht et al. (2025) Impacts of bed topography resolution on sea-level rise projections from coupled subglacial hydrology and ice dynamics for Thwaites Glacier, Antarctica

Identification

• Journal: Open MIND
• Year: 2025
• Date: 2025-10-13
• Authors: Ehrenfeucht, Shivani, Dow, Christine
• DOI: 10.5061/dryad.xd2547dvb

Research Groups

• Potsdam Institute for Climate Impact Research
• University of Waterloo

Short Summary

This study investigates the impact of bed topography resolution on sea-level rise projections from coupled subglacial hydrology and ice dynamics for Thwaites Glacier, West Antarctica. It finds that specific bed topography is a first-order control on accumulated mass loss, but final sea-level rise does not scale with bed resolution, and coupling between hydrology and ice dynamics accelerates mass loss.

Objective

• To assess how different resolutions of bed topography, particularly when coupled with subglacial hydrology and ice dynamics models, influence projections of glacier evolution and sea-level rise for Thwaites Glacier, West Antarctica.

Study Configuration

• Spatial Scale: Thwaites Glacier, West Antarctica. Bed topography resolutions of 100 meters, 500 meters, and 5 kilometers.
• Temporal Scale: Simulations project glacier evolution until the year 2300 (approximately 285 years from an implied start around 2015).

Methodology and Data

• Models used: Ice-sheet and Sea-level System Model (ISSM), Glacier Drainage System Model (GlaDS). GlaDS is implemented within ISSM.
• Data sources: Model outputs from 9 simulations varying bed resolution and subglacial hydrology representation (synchronous coupling, steady-state GlaDS effective pressure, or perfect connectivity to the ocean). Initial conditions derived from inversion and thermal model steps. Bed topography data (interpolated from radar surveys).

Main Results

• The specific bed topography exerts a first-order control on accumulated ice mass loss.
• Final sea-level rise projections do not scale directly with the resolution of the bed topography.
• Coupling between subglacial hydrology and ice dynamics results in faster ice mass loss.
• Current projections may underestimate uncertainty linked to unresolved bed features, underscoring the importance of continued high-resolution topography mapping.

Contributions

• Highlights the critical importance of high-resolution bed topography mapping for accurate ice sheet modeling and sea-level rise projections.
• Demonstrates that the specific bed topography, rather than merely its resolution, is a primary driver of accumulated ice mass loss.
• Shows that dynamic coupling between subglacial hydrology and ice dynamics significantly accelerates ice mass loss.
• Suggests that current sea-level rise projections may underestimate uncertainties due to unresolved subglacial features.

Funding

• Natural Sciences and Engineering Research Council: RGPIN-03761-2017
• NSERC Canada Research Chairs: CRC 950-231237

Citation

@article{Ehrenfeucht2025Impacts,
  author = {Ehrenfeucht, Shivani and Dow, Christine},
  title = {Impacts of bed topography resolution on sea-level rise projections from coupled subglacial hydrology and ice dynamics for Thwaites Glacier, Antarctica},
  journal = {Open MIND},
  year = {2025},
  doi = {10.5061/dryad.xd2547dvb},
  url = {https://doi.org/10.5061/dryad.xd2547dvb}
}