Agence France-Presse: Three British explorers have set out on a 90-day skiing expedition to the North Pole, measuring sea ice thickness the whole way to find out exactly how fast it is disappearing, according to the Catlin Arctic Survey. The data gathered will complement satellite and submarine observations and help ice modelling of the polar ice by experts, including Wieslaw Maslowski, who recently predicted the Arctic Ocean could be ice free as early as 2013, the London-based survey said in a …