Huge iceberg breaks off Antarctica

Scientists say a vast iceberg weighing billions of tonnes which broke off the Antarctic continent this month poses a potential threat to the circulation of the world's oceans.

They say the 2,500 square kilometre iceberg, floating south of Australia, could block an area that produces a quarter of the world's dense and very cold seawater, known as bottom water.

This water drives ocean currents, and scientists say weather patterns could be affected in decades to come.

Dr Neal Young is a glaciologist at the Antarctic Climate and Ecosystems Co-operative Research Centre in Tasmania.

First broadcast 26 February 2010