Ice Flow Along an I.A.G.P. Flow Line and Interpretation of Data From an Ice Core in Terre Adélie, Antarctica

Abstract An ice core has been obtained to the bedrock about 300 m deep in Terre Adélie, 5 km inland from the coast. Stable isotopes and gas content have been measured over the length of the core. The results have been interpreted in terms of the temperature and elevation of origin of the ice further inland on the ice sheet from the data obtained along an 800 km traverse towards Dome “C”, and from Dome “C”, at an elevation of about 3 200 m. The flow of the ice from Dome “C“ to the coast has been modelled to determine the ages and particle trajectories of the ice for present conditions. It has been found that the upper isotope and gas-content values in the core can be matched with the present regime using a base for ice flow above the present bed which is suggested by moraine in the ice core. The ice in the layer from the 200 m depth, where the age is apparently more than 5 000 years, to the 250 m depth, appears to have originated from conditions which differ substantially from those existing on the present inland ice-sheet surface. The results give an indication of a colder climate and greater ice-sheet thickness in the past.