Arctic Ocean. The Arctic Ocean lies to the north of Europe, Asia, and North America, and surrounds the North Pole; it is usually defined as the water area within the Arctic Circle. Physiographically, the Norwegian Sea and Greenland Sea, situated between Norway and Greenland, belong to the same basin as the Arctic Ocean. If the Arctic Ocean be regarded as lying wholly within the Arctic Circle, then it is almost land-locked between that circle and the parallel of 70° N. It communicates with the Pacific by Behring Strait, and with the Atlantic through Davis Strait and the wide sea between Norway and Greenland. The area of the ocean is about 5,500,000 sq. m., and into it there drain about 8,600,000 sq. m. of land. The coasts of Europe and Asia are low, and have several deep indent*tions, the principal being the White Sea and Gulf of Obi. The shores of North America are skirted by a most irregular assemblage of islands, forming numerous gulfs, bays, and channels. The principal rivers from Asia are the Lena, Yenesei, and Obi; from Europe, the Onega, Dwina, and Petchora; from America, the Mackenzie. The Arctic highlands are covered with an enormous depth of snow and ice. In some places this results in the formation of great glaciers, one of the most remarkable of which is the Humboldt Glacier, in 79° N. lat., on the west coast of Greenland. There are, however, no large, flat-topped tabular icebergs, like those of the southern hemisphere, within the Arctic Ocean; and this of itself is good evidence that there is no expanse of land towards the North Pole. The whole ocean is covered by immense ice-fields from 5 to 50 feet in thickness. During winter these are bound together by the severe frost, but these continuous masses break up during the summer months into floes and floe-bergs. Sometimes vast spaces of water and long lanes are formed between the floes and ice-fields, and these have, doubtless, given rise to the notions regarding an open Polar Sea which at one time prevailed. When these great floating ice-fields come together, the margins where they collide are piled up on each other, and thus is produced the well-known hummocky icefloes. When this hummocky ice is jammed against a shallow shore, and becomes fixed for long periods of time, the appearances are produced to which Nares gave the name of ' Palseocrystic Sea.' In the more open parts of the ocean the ice is, however, always in motion. Immense quantities of field and hummocky ice pass down each year between Spitzbergen and Greenland, and Greenland and Iceland. Parry reached a latitude of 82° 45', Markham reached 83° 20', and Lockwood (of Greely's expedition, 1882) 83° 24', the most northerly point yet attained. In 1850 M'Clure entered Behring Strait, and brought his crew home by Davis Strait, thus discovering the North-west Passage. In 1878 and 1879 Nordenskiold sailed from the Atlantic to the Pacific along the northern shores of Europe and Asia, thus discovering the North-east Passage. In 1893 Nansen set forth on his novel and adventurous expedition; hoping that his ship would be carried by the current, after being frozen in the ice, from the shores of Asia across or near the North Pole, and ultimately out into the open sea again off the coasts of Greenland. The ocean appears to be shallow to the north of Europe and Asia, the depth 500 miles to the north of the Lena being only 38 fathoms; but between Spitzbergen and the north of Greenland there is a deep opening into the frozen sea, where the depth is 2500 fathoms. Whales, seals, and walruses are now a much less plentiful source of wealth than they used to be. In winter the temperature of the air is sometimes as low as - 47° F., and in summer is usually a little above the freezing-point.
See books on Arctic exploration or special expeditions by Kane (1853), M'Clintock (1859), Blake (1874), Markham (1874, 1878, and 1881), Payer (1876), Nares (1878), Nordenskiold (1881), De Long (1882), Gilder (1883), Greely (1886), Nansen (1897), Peary (1898), and Dittmar (1901).