50 years of ice-front changes between the Adelie and Banzare Coasts, East Antarctica

Ice-front change may well be a sensitive indicator of regional climate change. We studied the coastal sector of Wilkes Land, East Antarctica, along the Adelie and Banzare Coasts, extending from Buchanan Bay (67degrees05' S, 144degrees30' E) to Porpoise Bay (67degrees S, 128degrees E). The glaciers in this area drain the northern part of Dome C (area 270 000 km(2)). A comparison of maps, photographs and satellite images, dated several years apart, led to an estimation of the fluctuations of 18 ice fronts over the 50 years 1947-97. The area of the floating glaciers in 1963 was 3035 km(2), and in 1989, 2785 km(2). The main glaciers in the area are Zelee, Astrolabe, du Francais, Commandant Charcot and Pourquoi Pas for the Adelie Coast, and Dibble, May, Sandford and Frost Glaciers for the Clarie and Banzare Coasts. Most of the floating glaciers have shown cyclical behaviour without a marked trend, but a general reduction since 1947. The reduction in the area of floating glaciers since the 1950s may be linked to changes in ice-ocean interaction, as noted for the floating glaciers of the George V Coast and the Cape Adare area, and sea-ice extent. The calving behaviour of the main glacier tongues is characterized by an accumulation of icebergs projecting from the coast to form iceberg tongues, held in place by grounding and joined together by annual or perennial fast ice.