Explorers to measure Arctic sea ice

LONDON, March 1 (UPI) -- Three British explorers measuring the depth of Arctic sea ice say they will don survival suits and swim with their gear when they encounter open water.

The team, led by Pen Hadow, began their 620-mile journey Saturday hundreds of miles north of Canada with a goal to finish by late May, the BBC reported Sunday.

Their mobile radar unit constantly measures the thickness of the ice and will provide data to help scientists determine how rapidly the ice is thinning, Hadow said. Some climate-change scientists have predicted the first Arctic ice-free summer may arrive as soon as 2013.

"If, as scientists tell us, the ice is thinning quickly, then it should set alarm bells ringing around the world," said the 46-year-old Hadow. The British Arctic Survey Group also includes Ann Daniels, 44 and Martin Hartley, 40.

In 2003, Hadow, from Hexworthy, Devon, became the first person to trek solo from Canada to the North Pole.