Agence France-Presse: A British explorer said Tuesday he would go ahead next year with a pioneering expedition to measure the thickness and density of the rapidly shrinking Arctic Ocean ice cap. Pen Hadow and two other British explorers will set off in February for a four-month, 1,200-kilometre (750-mile) trek to the North Pole to take samples of ice, snow and air. The trip had been due to start in February this year but was postponed to allow the expedition’s scientific remit to be …