Newcastle University

Despite a world-wide effort to understand the changes being brought about by climate change, the question over how fast the ice caps are melting remains largely unanswered.

Now an international team of experts are leading an investigation which could finally give a definitive answer about the impact Antarctica is having on sea level change globally.

Newcastle and Bristol universities have been awarded £760,000 by the Natural Environment Research Council (NERC) to investigate the changing mass of the Antarctic Ice Sheet.

Using a combination of satellite observations, Global Positioning System (GPS) data and climate model output, the team hopes to be able to determine the evolution of the mass of the Antarctic ice sheet over the last 20 years.

Dr Matt King, Reader in Polar Geodesy who is leading the Newcastle University side of the project, explained: “There are now lots of measurements that tell us something about the recent state of the Antarctic Ice Sheet, but none of those measurements gives the complete picture.

“The project aims to bring together the strengths of every data set to gain the most accurate estimate of Antarctica's contribution to sea level as a whole, as well as identify which regions are changing and which are not.”

The team, which includes academics from the University of Bristol and partners from the Netherlands and USA, aims to tackle the controversy around how well we understand recent ice-mass loss.

“Here at Newcastle University we are using GPS data to measure the motion of the bedrock surrounding the ice and poking out from amongst it on mountain outcrops,” explains Dr King.

“Because the ice sitting on the Antarctic continent compresses the bedrock like a spring, measuring its motion tells us something about changes in the mass of ice sitting on top.  To do this requires measurements with accuracies of better than one millimetre-per-year – the thickness of a fingernail.

“There is also a much slower response from the solid Earth to the changing ice mass - due to the flow of molten rock within the Earth's mantle more than 100km below the surface.

“This change lasts thousands of years and also causes the surface to move, so the same GPS measurements, incredibly, also tell us something about ice mass change since the last Ice Age 20,000 years ago, all the way to the present.”

The project is being led by Professor Jonathan Bamber of the University of Bristol.