Two icebreaking ships have become the first surface vessels to traverse the Canada Basin, the ice-covered sea between Alaska and the North Pole.
The scientists aboard the ships were engaged in oceanography, marine geology and geophysics observations in the unexplored region to better understand the Arctic's role in climate change
The Swedish vessel Oden and the U.S. Coast Guard's Healy completed the historic trek in September.
Although the same area had been crossed by submarines, the central Arctic Ocean is Earth's least explored ocean area by surface ships due to floating sea ice that, in some areas, is more than 10 feet thick.
Jim Swift of the Scripps Institution of Oceanography said the Canada Basin crossing was made possible because of a reduction in the Arctic Ocean's ice cover.
"Some indications have shown the ice volume in the Arctic Ocean has reduced nearly 40 percent since the time submarine transects began more than 40 years ago," said Swift. "There is some scientific debate about the actual percentage, but there is no doubt of the thinning in many areas of the region."
Other expedition scientists were from Sweden, Finland, Canada, Germany, Norway and Denmark.
Copyright 2005 by United Press International
Explore further: Sea ice strongly linked to climate change in past 90 000 years