North Pole Since 2002, the Russians have also annually established a base, Barneo, close to the Pole. This operates for a few weeks during early spring. Studies in the 2000s predicted that the North Pole may become seasonally ice-free because of Arctic ice shrinkage, with timescales varying from 2016 to the late 21st century or later. The sea depth at the North Pole has been measured at by the Russian Mir submersible in 2007 and at 4,087 m (13,410 ft) by USS "Nautilus" in 1958. The nearest land is usually said to be Kaffeklubben Island, off the northern coast of Greenland about
North Pole on a runway prepared on the ice) or by icebreaker have become relatively routine, and are even available to small groups of tourists through adventure holiday companies. Parachute jumps have frequently been made onto the North Pole in recent years. The temporary seasonal Russian camp of Barneo has been established by air a short distance from the Pole annually since 2002, and caters for scientific researchers as well as tourist parties. Trips from the camp to the Pole itself may be arranged overland or by helicopter. The first attempt at underwater exploration of the North Pole was made on 22