FORM, STRUCTURE AND STABILITY OF THE MARGIN OF THE ANTARCTIC ICE-SHEET, VESTFOLD HILLS AND BUNGER HILLS, EAST ANTARCTICA

Studies of glacier margins have suggested that form and structure can be used to infer mass balance condition and stability. This paper exam ines this idea by investigating the form and structure of the Antarcti c ice sheet at two coastal eases in East Antarctica. Two principal for ms of the margin of the ice sheet in the Vestfold and Bunger hills tha t are discussed are ice cliffs and gently-sloping ice margins with an inner moraine. The form of the ice margins in both areas is primarily related to the accumulation of drift snow and superimposed ice and not to mass balance condition. It is concluded that the form and structur e of ice margins are ambiguous indicators of mass balance condition an d stability and that a change in mass budget is probably neither a suf ficient nor a necessary condition for a change in the morphology of ic e margins. Although we argue that the form and structure of the ice ma rgins tells us little about stability, interpretation of the Holocene history and geomorphology of the eases suggests that the ice margins h ave been stable at least throughout the Holocene and that this conditi on of overall stability continues today.