 It was estimated in May, 2007 to be between thick, on average.The freed segment of the ice shelf, known as Ayles Ice Island, drifted southwesterly for two years, and in January 2007 accelerated into the open Arctic Ocean, causing concern for oil rig operators in the Beaufort Sea north of Prudhoe Bay, Alaska.In August 2007, however, the island became wedged into the Sverdrup Inlet of the Queen Elizabeth Islands.