Antarctic ice sheet on brink of change

A project to map part of the West Antarctic Ice Sheet has shown that the region may be on the threshold of change.

Scientists from the University have mapped the ice-covered, largely unexplored landscape from the air.

They uncovered a deep sub-glacial basin close to the edge of the ice sheet near the Weddell sea.

The basin measures 100 by 200 km - about the size of Wales - and is well below sea level, nearly 2km deep in places.

The ice sheet, currently grounded above the deep basin, may be more unstable than previously thought and could quickly undergo ice loss.

Hidden landscape

Researchers surveyed the thickness of two ice streams to determine the underlying landscape.

Their measurements reveal a steep slope and a large subglacial basin upstream of where the West Antarctic Ice Sheet meets the Weddell Sea.

The study was carried out in a collaboration led by the University of Edinburgh with British Antarctic Survey and the Universities of Aberdeen, Exeter and York.

Climate change

In a related study models predict that the Weddell Sea region may experience warmer ocean conditions at the end of the 21st century.

Pulses of warm ocean water that could reach far beneath the Ice Shelf and affect its stability.

Scientists say this could provide the trigger for ice sheet change.

This is a significant discovery in a region of Antarctica that at present we know little about. The area is on the brink of change, but it is impossible to predict what the impact of this change might be without further work enabling better understanding of how the West Antarctic Ice Sheet behaves.

Professor Martin Siegert

School of GeoSciences

This article was published on May 9, 2012