Scientists help map Antarctic ice sheets (11/3/2007)

Newcastle University scientists are joining the race to discover how climate change is affecting Antarctic ice sheets.

Researcher David Barber will spend four months installing GPS signal receivers on two huge plateaus of ice that cover the sea, so that their movements can be monitored by satellite.

These measurements will enable other members of the project team in Newcastle, led by Dr Matt King (pictured), to calculate how much the ice sheets rise and fall with the tides. This will pave the way for much more accurate measurements of the thickness of the ice sheets, so that scientists will know whether and how fast the ice is melting.

David flies out to west Antarctica on 6 November and over the next few weeks will plant about 15 receivers on the vast Ronne ice shelf, which is about the same size as France.

He will then plant receivers on the smaller Larsen ice sheet, which featured in the opening scenes of the climate change disaster movie, The Day After Tomorrow, in which Hollywood special effects made it appear as if the ice sheet cracked as it was being drilled.

Matt said: 'The Larsen sheet is quite famous because a couple of years ago, a chunk about half the size of Cumbria and a few hundred metres thick broke off in a matter of days - you could say that the real life scenario has exceeded Hollywood's expectations!'

As a result, there was a very small increase in sea level, but scientists need to know the condition of the ice sheet across its whole expanse, said Matt.

'Satellite measurements have helped us make great progress in mapping the entire ice sheet, but we still don't actually know how quickly the ice sheets are melting, if at all, but it is important that we find out and monitor the situation so that we can anticipate any rise in sea level.

'The tides are very large in this part of the world - perhaps eight to ten metres - and we need to know how this affects the ice sheets lying on top of the sea before we can measure their thickness.

The research project is being carried out by the School of Civil Engineering and Geosciences at Newcastle University and is being funded by the Natural Environment Research Council. Support for the project is being provided by the British Antarctic Survey and the Earth and Space Research organisation, Oregon, USA.

Once the effects of the tides have been taken into account, the picture will be much clearer. Upwards movement will mean a thickening of the ice and downwards thinning. Seasonal variations are normal but scientists will be looking for long-term changes.

David said: 'Using satellites, we can now measure any movement on the Earth's surface to an accuracy of a few millimetres. This is a very good way to measure small annual changes in the thickness of ice but you have to know about other movements, such as those caused by tides, first.'

David, who lives in North Shields, will fly out from RAF from Brize Norton in Oxfordshire to the Ascension Islands and then on to the Falklands. From there, he will fly to the British Antarctic Survey base at Rothera, in West Antarctica.

Staff from the Survey base will assist David on his project, which will involve flying to various points on the two ice shelves and installing the receivers, along with solar panels and wind turbine generators to power them.

David expects to be in the Antarctic until February. Because it will be the summer time, temperatures at the base are likely to be only a few degrees below freezing point, although temperatures as low as -20C are possible on the inner edge of the Ronne ice shelf. A few of the GPS receivers will be left for the winter to be retrieved the following Antarctic summer, experiencing temperatures perhaps as low as -40C in the winter.

Note: This story has been adapted from a news release issued by Newcastle University

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