Oceanic heat flux, on-shelf flow and basal melting of the Totten Glacier, East Antarctica
Oceanic heat flux, on-shelf flow and basal melting of the Totten Glacier, East Antarctica
Authors
David E. Gwyther
Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia
Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001
Ben Galton-Fenzi
Australian Antarctic Division, Hobart, Tasmania, Australia
Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001
John Hunter
Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001
Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia
Jason Roberts
Australian Antarctic Division, Hobart, Tasmania, Australia
Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001
Abstract
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.
