TILE ARCTIC OCEAN is the body of water en circling the North l'ole, and included between the northern boundaries of Europe. Asia, North America, Greenland. and the north Atlantic Ocean above the Arctic Circle, with which latter ocean it is in open connection, while it is in communication with the Pacific Ocean only through the narrow Bering Strait. It drains a vast area, including the northern parts of North America and of Asia. The great rivers, Obi, Yenisei, and Lena, in Asia. and the Mac kenzie, in Canada, empty into this ocean. Its area is estimated at between 4.000,000 and 5,000,000 square miles. How much of this area is covered by land is uncertain; but the con siderable depth of soundings taken by Arctic explorers would seem to indicate an extensive polar Sea. It is hardly probable that any im portant land areas exist in the region that stretches from the pole southward, to the north ern point of the archipelago above Greenland, to the mouth of the Mackenzie, to Bering Strait, to the northern point of Siberia. and to the northern point of Franz-Josef Land. The water region immediately surrounding the pole is covered with great fields of ice, which are frozen together in winter, hut become separated to a greater or less degree (especially at the edges where ice floes are formed) during the summer. This ice area is called the ice-pack, and it extends somewhat to the southward of latitude 75' N. above Bering Strait and the adjoining American and Asiatic coast, between the limits of longitude 160° E. and 130° IV.; to the west ward and eastward of this region the pack limit retreat* northward; and in longitude 120° AV., it is found at about latitude 78° N.: in longi tude 90' IV., at about latitude 78° N.; in longi
tude 85° \V,, at about latitude 81° N.; in longi tude 50' AV., at about latitude 83' N. On the east coast of Greenland the ice-pack descends to latitude 78° N., to retreat again to 82° or 83° N., north of Spitzbergen and Franz-Josef Land, where this latitude is preserved as far east as longitude 100° east of Greenwich, when the detour toward the south begins, which reaches its limit at about longitude 173° E. This ice is kept in sluggish motion, principally by the winds, in such a manner that a vessel lodged in the ice at a point north of Alaska, or even of Siberia. would gradually drift toward the pole and, passing beyond that, would con tinue southward until set free from the ice near Spitzbergen or Greenland. Naneen made such a drift in 1893-96. The depth of the Arctic Ocean is variable, being very shoal (only a few hundred feet deep) north of western North America and eastern Asia, where, however, meas urements have not been made above latitude 75° north, and very deep (7000 to 15,000 feet) near where its waters join the North Atlantic. Northward of the continent of Europe the depth is from 600 to 1200 feet, and northward of Spitz bergen and Franz-Josef Land 10.000 feet. The Arctic Geean is apparently affected by tides, in which the monthly variations are more important than are the semi-diurnal, but both these are masked by the influence of the winds and the ice. The assumption that a great portion of the Arctic Ocean has for a long time been covered with solid pack of ice has suggested for it the name of Paleoerystie Sea, or the Sea of Ancient Ice.