Summary

Past changes in East Antarctic Ice Sheet (EAIS) volume are poorly known and diffi cult to measure, yet are critical for predicting the response of the ice sheet to modern climate change. In particular, it is important to identify the sources of sea-level rise since the Last Glacial Maximum (LGM), and ascertain the present-day stability of the world’s largest ice sheet. We present altitudinal transects of 10Be and 26Al exposure ages across the Framnes Mountains in Mac. Robertson Land that allow the magnitude and timing of EAIS retreat to be quantifi ed. Our data show that the coastal EAIS thinned by at most 350 m in this region during the past 13 k.y. This reduction in ice-sheet volume occurred over an ~5 k.y. period, and the present icesheet profi le was attained ca. 7 ka, in contrast to the West Antarctic Ice Sheet, which continues to retreat today. Combined with regional offshore and terrestrial geologic evidence, our data suggest that the reduction in EAIS volume since the LGM was smaller than that indicated by contemporary ice-sheet models and added little meltwater to the global oceans. Stability of the ice margin since the middle Holocene provides support for the hypothesis that EAIS volume changes are controlled by growth and decay of Northern Hemisphere ice sheets and associated global sea-level changes.

Authors:Mackintosh A. White D. Fink D. Gore D.B. Pickard J. Fanning P.C. Published in: 2007 Category 1: Peer-reviewed literature Program area: Geosciences
Mackintosh A., White D., Fink D., Gore D.B., Pickard J., Fanning P.C. (2007) Exposure ages from mountain dipsticks in Mac. Robertson Land, East Antarctica, indicate little change in ice-sheet thickness since the Last Glacial Maximum, Geology 35(6). 551-554;

Related projects

Subsurface investigations of Marine Plain GORE, Prof. Damian Vestfold Hills, Davis, Marine Plain Mule Peninsula ASPA, Australia (or home country)
Glacial history of the Framnes Mountains, East Antarctica. GORE, Prof. Damian Mawson, Framnes Mountains
on