15 July 1998

Antarctic Voyagers To Skate On Thin Ice

A major Australian expedition to the Antarctic is about to get underway to study "polynyas" - areas of open water and thin ice that occur near the coast in regions otherwise covered by pack ice.

The 54-member expedition of biologists, glaciologists, oceanographers and meteorologists is part of Australia's research contribution to the International Year of the Ocean.

Senator Ian Macdonald, Australian Parliamentary Secretary for the Antarctic described the expedition as necessary because "understanding all the processes occurring within the polynyas is important in understanding other global climate issues".

A key issue for the research is exploring whether or not the polynyas might be in part caused by the katabatic winds sweeping down from the Mertz Glacier - explaining the ice-free conditions around the coast of Adelie Land.

Antarctic Bottom Water will be another item investigated by this research voyage. This dense water is created as ice forms. This then sinks, trapping oxygen and other gasses, which are then spread throughout the world's oceans. Previous research by the Co-operative Research Centre for Antarctica and the Southern Ocean estimates the volume of the worlds oceans formed this way may be as much as 25 percent.

Biologists onboard the Aurora Australis for the voyage will also look at the polynya's impact on birds, seals, whales and krill. The expedition is due back to Hobart in September this year.