Oceanic heat flux, on-shelf flow and basal melting of the Totten Glacier, East Antarctica

• Main Authors: Gwyther, DE, Galton-Fenzi, B, Hunter, JR, Roberts, Jason
• Format: Conference Object
• Language: English
• Published: Australian Antarctic Division and Antarctica New Zealand 2013
• Subjects: Earth Sciences; Oceanography; Physical Oceanography; Antarctic; East Antarctica; The Antarctic; Totten Glacier; Antarc*; Antarctica; Ice Sheet; Ice Shelf; Totten Ice Shelf
• Online Access: http://ecite.utas.edu.au/90793

The Totten glacier and ice stream drains a large proportion of the Antarctic Ice Sheet, much of it grounded below sea level and susceptible to rapid mass loss. Increased basal melting reduces the buttressing effect of the ice shelf, leading to accelerated glacial flow and thinning. The state of the grounded ice sheet is therefore susceptible to changes in ocean heat flux and circulation. The Totten glacier has recently been observed to be thinning (at 1.9 m/yr). It is believed that the change exhibited by the Totten glacier is from changes in oceanic forcing - but the details, extent and magnitude of the interaction is unknown. Here we present a model, based on the Regional Ocean Modelling System, that has been developed to simulate the interaction between the Totten ice shelf and the ocean, with the aim of pinpointing causal factors of basal melting. Publicly available bathymetry and ice thickness datasets provide the geometry while the model is forced by currents, tides, buoyancy fluxes and wind on the surface and lateral boundaries. Analysis of model output shows basal melt rates in agreement with glaciological estimates. Ocean currents simulated by the model supply significant heat across the continental shelf break and into the topographic basin in front of the ice shelf. Therefore this study links basal melt of the Totten ice shelf to ocean heat transport. This is the first such modelling study of this region, and will provide valuable information for directing future observational missions.