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
Ice cap climate Mountains, the Caucasus, and the Alps. Mars, like Earth, has ice caps at its poles. In addition to frozen water, Mars ice caps also have frozen carbon dioxide, commonly known as dry ice. In addition, Mars has seasons similar to Earth. The North Pole of Mars has a permanent water ice cap and a winter-only dry ice cap. On the south pole, both the water and carbon dioxide are permanently frozen. Europa, a moon of Jupiter, is covered with a permanent sheet of water ice, similar to Antarctica. Scientists theorize that it may have sub-glacial lakes similar to those seen