Subglacial Freshwater Drainage Increases Simulated Basal Melt of the Totten Ice Shelf

Subglacial freshwater discharge from beneath Antarctic glaciers likely has a strong impact on ice shelf basal melting. However, the difficulty in directly observing subglacial flow highlights the importance of modeling these processes. We use an ocean model of the Totten Ice Shelf cavity into which we inject subglacial discharge derived from a hydrology model applied to Aurora Subglacial Basin. Our results show (a) discharge increases melting in the vicinity of the outflow region, which correlates with features observed in surface elevation maps and satellite-derived melt maps, with implications for ice shelf stability; (b) the change in melting is driven by the formation of a buoyant plume rather than the addition of heat; and (c) the buoyant plume originating from subglacial discharge-driven melting is far-reaching. Basal melting induced by subglacial hydrology is thus important for ice shelf stability, but is absent from almost all ice-ocean models.

Automated summary

Subglacial freshwater discharge from beneath Antarctic glaciers has a significant impact on ice shelf basal melting. The difficulty in directly observing this process highlights the importance of modeling. By injecting subglacial discharge into an ocean model, we show that it increases melting in the outflow region, driven by the formation of a buoyant plume rather than heat addition, and has far-reaching effects. Subglacial hydrology-induced basal melting is crucial for ice shelf stability but often overlooked in ice-ocean models.