The contribution that key regions of the Antarctic ice sheet are making to global sea-level rise is a cause for concern according to Director of British Antarctic Survey (BAS), Professor Chris Rapley. Speaking this week at the AAAS in St Louis he summarised the latest understanding from one of the frozen continent's most remote and inhospitable corners.
Professor Rapley said, "Parts of the Antarctic ice sheet that rest on bedrock below sea level have begun to discharge ice fast enough to make a significant contribution to sea level rise. Understanding the reason for this change is urgent in order to be able to predict how much ice may ultimately be discharged and over what timescale. Current computer models do not include the effect of liquid water on ice sheet sliding and flow, and so provide only conservative estimates of future behaviour. Only five years ago, Antarctica was characterised as a slumbering giant in terms of climate change. I would argue that this is now an awakened giant and we should take notice."
In recent years glaciers in the Amundsen Sea sector of the West Antarctic ice sheet and two in East Antarctica have shown rapid thinning. Their common feature is that they all lie on rock well below sea level. The discharge in West Antarctica prompted scientists from BAS, US National Science Foundation and the University of Texas to embark on an airborne geophysical survey of the little visited area of the continent. Using two Twin Otter aircraft kitted out with a suite of survey instruments, the scientists collected data from the Pine Island and Thwaites glaciers and their catchments. These new results provide a quantum jump in our knowledge of the bed topography and internal layering of the ice sheet in the region, and will result in due course in much improved estimates of its future contribution to sea level worldwide.
Issued by the British Antarctic Survey Press Office.
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NOTES TO EDITORS:
In 2001 the Intergovernmental Panel on Climate Change (IPPC) predicted future sea level rise on the assumption that the Antarctic ice sheet would not make a significant contribution over the next one hundred years. Recent data from the Pine Island and Thwaites glaciers in Antarctica suggest that this area is making a contribution, but whether this is a short-term fluctuation, or a result of recent or ancient climate change, is an open question. Our ability to predict the future of this part of the West Antarctic ice sheet is limited and basic information such as the ice sheet thickness and conditions beneath the ice at bedrock are required to build numerical models that will allow robust prediction.
British Antarctic Survey is a world leader in research into global issues in an Antarctic context. It is the UK's national operator and is a component of the Natural Environment Research Council. It has an annual budget of around £40 million, runs nine research programmes and operates five research stations, two Royal Research Ships and five aircraft in and around Antarctica. More information about the work of the Survey can be found at: www.antarctica.ac.uk
Chris Rapley Prof Chris Rapley CBE is Director of the British Antarctic Survey (BAS). Prior to this he was for four years the Executive Director of the International Geosphere-Biosphere Programme (IGBP) at the Royal Swedish Academy of Sciences in Stockholm. This followed an extended period as Professor of Remote Sensing Science and Associate Director of University College London's Mullard Space Science Laboratory. He has a first degree in physics from Oxford, a M.Sc. in radioastronomy from Manchester University, and a Ph.D. in X-ray astronomy from University College London. He has been a Principal Investigator on both NASA and European Space Agency satellite missions and is a member of the NASA JPL Cassini mission Science Team. He has been a member of numerous national and international committees and boards including Vice President of the Scientific Committee for Antarctic Research and Chair of the International Council for Science's (ICSU) International Polar Year 2007-2008 (IPY) Planning Group. He is currently a member of the European Polar Board's Executive and ICSU - World Meteorological Organisation (WMO) Joint Committee for IPY. He is a Fellow of St Edmund's College Cambridge, and is an Honorary Professor at University College London and at the University of East Anglia.
The International Geosphere-Biosphere Programme, IGBP, is an international scientific research programme that networks scientists from around the world to conduct interdisciplinary Earth System science and global change research. www.igbp.net
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