Cold war thaw fuels Arctic study

六月 7, 1996

The thaw in the cold war has led to pioneering glaciology research in the Russian Arctic that aims to produce better predictions of the effects of global warming.

The centre for glaciology at the University of Wales, Aberystwyth, has won more than Pounds 1 million since 1994 to study the link between glaciers and climate change. Around half has come from the Natural Environmental Research Council, which along with INTAS, the international body promoting co-operation with scientists in the former Soviet Union, has provided substantial grants for collaborative field work on the Russian ice caps.

The Aberystwyth centre was founded to tackle the scientific problems of global sea-level rise and climate change, and carries out studies of the past, present and future behaviour of Arctic glaciers, permanent but mobile ice masses formed from compacted snow.

These glaciers are likely to be particularly sensitive to the greenhouse effect, with computer models predicting that the Arctic will warm significantly more than lower latitudes.

Centre director, Julian Dowdeswell, says scientists already know that glaciers in many areas of the Arctic, from the north of Canada to Spitsbergen and the Russian Arctic, have been decaying since the end of the "Little Ice Age" around a century ago.

"We know that sea levels have risen by about two millimetres per year over the past 100 years, and if that amount of water has been decanted since the end of the Little Ice Age, we would expect it to increase as warming continues," said Professor Dowdeswell.

If glaciers were to melt completely, sea levels would rise by 70 metres, and if even a small proportion of their total mass melts, sea levels could rise globally by between 20 and 30cm during the next 50 years, said Professor Dowdeswell.

The prospect of Arctic melting makes the links between glaciers, climate change and sea level of interest both to scientists and to the global population over the space of a single lifetime. "If the sea level does rise, we have to estimate the useful life of, for example, the Thames Barrier, which might have to be reconstructed."

It is likely that small glaciers and ice sheets will continue to melt in a warming world, and scientists have to consider events that could occur under extreme conditions, such as a depression over the North Sea, which itself causes a rise in the sea's surface, combined with a high spring tide and storm waves.

The International Panel for Climate Change produces various estimates of the effects of global warming, but until now, these have been unable to include data from the Russian Arctic, an area which has been closed to western scientists since the 1920s.

There are almost 100,000 square kilometres of glacier ice on the archipelagos of the Eurasian Arctic, but maps of the Russian area are very poor, partly for military reasons. While the Antarctic and Greenland are the world's major ice cap areas, the Arctic represents a significant proportion of the remainder, and it is important to know as much as possible about it, says Professor Dowdeswell.

A formal link between the Royal Society and the Russian Academy of Sciences paved the way for high- resolution satellite images of caps. The NERC and INTAS support then allowed the Aberystwyth researchers to take part in an airborne project, using the radar on a Russian helicopter to measure the ice, with some of the team also involved in field investigations on the ground with Russian and US colleagues.

The deepest ice measured was over 400 metres thick. The findings are being incorporated into the centre's computer modelling studies, reconstructing the sensitivity of the ice on Franz Josef Land to climate change over the past 18,000 years. The researchers hope this will underpin more accurate predictions of the effects of global warming.

The centre has had encouraging results testing its computer models of past activity against the actual geological record, and is planning another Russian expedition next year to build up more data.

Professor Dowdeswell was chief scientist on the first Arctic research cruise of the James Clark Ross, the UK's new ice-strengthened research ship.

The voyage mapped the glacier-influenced continental slope of the polar North Atlantic, using a state-of-the-art long-range sonar system to produce an image of the sea floor comparable to aerial photographs of land.

Ice within major troughs and fiords has deposited debris to the edge of the continental shelf, and that has formed huge sedimentary fans. The centre's research shows that the cyclical nature of these sediment deposits is driven by long-term changes in the Arctic climate, and this can now be used to reconstruct the climate changes in a bid to improve predictions.

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