Terrain: central surface covered by a perennial drifting polar icepack that, on average, is about 3 m thick, although pressure ridges may be three times that thickness; the icepack is surrounded by open seas during the summer, but more than doubles in size during the winter and extends to the encircling landmasses; the ocean floor is about 50% continental shelf (highest percentage of any ocean) with the remainder a central basin interrupted by three submarine ridges (Alpha Cordillera, Nansen Cordillera, and Lomonosov Ridge)
major surface currents: two major, slow-moving, wind-driven currents (drift streams) dominate: a clockwise drift pattern in the Beaufort Gyre in the western part of the Arctic Ocean and a nearly straight line Transpolar Drift Stream that moves across the ocean from the New Siberian Islands (Russia) to the Fram Strait (between Greenland and Svalbard); sea ice that lies close to the center of the gyre can complete a 360 degree circle in about 2 years, while ice on the gyre periphery will complete the same circle in about 7-8 years; sea ice in the Transpolar Drift crosses the ocean in about 3 years
Definition: This entry contains a brief description of the topography.
Source: CIA World Factbook - This page was last updated on January 20, 2018
