Geology 35, 551–554 (2007)

Credit: PUNCHSTOCK

The East Antarctic Ice Sheet has changed relatively little in volume since the Last Glacial Maximum and has been stable for thousands of years, according to a new study.

Andrew Mackintosh at the Victoria University of Wellington and colleagues dated rock exposure ages and positions across the Framnes Mountains in East Antarctica to calculate the extent and timing of ice sheet retreat since the Last Glacial Maximum. The mountain range, which runs north to south perpendicular to the ice sheet margin, extends more than 400 m above the present-day ice sheet surface and contains rocks that were deposited sequentially as the ice retreated. From their analyses, the researchers found that the coastal ice sheet has thinned, at most, by 200 to 350 m in the past 13,000 years and has remained essentially unchanged for the past 7,000 years.

Retreat of the ice sheet during this period was driven largely by rising sea levels rather than by changes in temperature or precipitation, say the researchers. The study suggests that a dramatic rise in sea level caused by melting of the West Antarctic Ice Sheet or in Greenland could pose a future risk to the world's largest ice sheet.