In a study published in Geophysical Research Letters, a team led by Duncan Wingham of University College London showed that the 5,400-square-kilometre glacier, one of the largest in Antarctica, has lost as much as 90 metres in height since 1994 and it’s surface is now dropping at a rate of up to 16 metres a year. The new figures have reduced estimates for the glacier’s lifespan from 600 years to only 100 years.

The centre of the glacier is showing the most rapid ice loss, suggesting that it may soon break up, which would, in turn, affect the ice sheet farther inland. The scientists suggest that the current melting will add around three centimetres to global sea level, but that the ice trapped behind it would contribute as much as 30 centimetres.

‘Because the Pine Island Glacier contains enough ice to almost double the Intergovernmental Panel on Climate Change’s best estimate of 21st-century sea-level rise, the manner in which the glacier will respond to accelerated thinning is a matter of great concern, said Andrew Shepherd of the University of Leeds, one of the paper’s co-authors.

October 2009