Self-regulating subglacial hydrology undermines bed-drying interventions in East Antarctica

[Geoengineering News]

https://essopenarchive.org/doi/abs/10.22541/essoar.15007972/v1

Authors: Yu Wang, Rupert Gladstone, Michael Wolovick, Chen Zhao, Poul Christoffersen, Benjamin K. Galton-Fenzi, and John Moore

27 August 2026

https://doi.org/10.22541/essoar.15007972/v1

Abstract

The Antarctic Ice Sheet may contribute multiple meters of global sea-level rise in coming centuries. Targeted geoengineering interventions, such as subglacial water extraction (’bed-drying’), have been proposed to increase basal friction and slow the retreat of marine-terminating glaciers. However, the efficacy of such interventions remains unquantified. Here, we use a fully coupled ice-hydrology model to evaluate bed-drying in the vulnerable Wilkes Subglacial Basin, East Antarctica. We show that removing basal water has minimal impact on mitigating sea-level rise and can paradoxically accelerate ice mass loss. Under natural conditions, abundant meltwater sustains efficient subglacial channels that act as pressure sinks, enhancing basal friction. Bed-drying starves and collapses this channelized network, forcing residual water into an inefficient, pressurized distributed sheet that artificially lubricates the bed. Our simulations suggest that successful interventions would require highly dynamic, spatially optimized extraction strategies, while a bad strategy could lead to instabilities and glacier surging. Ultimately, disrupting the intrinsic self-regulating mechanisms of subglacial drainage carries systemic glaciological risks.

Source: ESS Open Archive