History of submarines few years before the US, and paralleled subsequent US development in this area. In the 1950s, nuclear power partially replaced diesel-electric propulsion. The sailing of the first nuclear-powered submarine, the USN ""Nautilus"" in 1955 was soon followed by similar British, French and Russian boats. Equipment was also developed to extract oxygen from sea water. These two innovations, together with inertial navigation systems, gave submarines the ability to remain submerged for weeks or months, and enabled previously impossible voyages such as the crossing of the North Pole beneath the Arctic ice cap by the USS "Nautilus" in 1958. Most of the
Ice cap climate an ice cap climate. However, this theory is disputed, and even proponents suggest there was an area of periodic melting near the equator. The two major areas with ice cap climates are Antarctica and Greenland. Some of the most northern islands of Canada and Russia also have ice cap climates. In addition, a large portion of the Arctic Ocean near the North Pole remains frozen year round, effectively making it an icecap climate. The Arctic Ocean is located in the Arctic region. As a result, the northern polar ice cap is the frozen part of that ocean's surface. The only