December 31, 2008

Sub to explore melting Antarctic glacier

British scientists plan to use a yellow submarine to explore beneath a giant melting Antarctic glacier whose collapse could raise sea levels 4 inches.

The scientists hope to find out why Pine Island Glacier, flowing west-northwest along the south side of the Hudson Mountains into Pine Island Bay, Amundsen Sea, is melting so quickly at its base, said the British Antarctic Survey, Britain's national Antarctic operator.

The 23-foot-long, robotic yellow submarine, nicknamed Autosub, will map out the glacier's underside, about two-thirds of a mile under water, while measuring changes in water temperature, pressure and salt content.

The glacier is thinning and accelerating, which means more ice is melting into the oceans and contributing to sea-level rise, lead researcher Adrian Jenkins told The Daily Telegraph.

We believe that something about the ocean around where the glacier ice moves from being grounded to floating has changed and this is driving the thinning and accelerating ice flow, he said.

Autosub, which has a maximum range of 248 miles and is powered by 5,000 ordinary D-cell batteries, will navigate its way for 40 miles underneath the glacier until it reaches land -- a journey that will take 20 hours, the newspaper said.

Using on-board sonar the sub will also create a three-dimensional map for scientists to see areas beneath the glacier that are most prone to melting.