II.

Boundaries and Size

The surface waters of the Arctic Ocean mingle with those of the Pacific Ocean through the Bering Strait, by way of a narrow and shallow channel, which has a depth of about 55 m (180 ft) and a width of about 65 km (40 mi). More importantly, the Arctic waters mix with those of the Atlantic Ocean across a system of submarine sills (shallow ridges) that span the great distances from Scotland to Greenland and from Greenland to Baffin Island at depths of about 500 to 700 m (1,640 to 2,300 ft). Except for the channels to the Atlantic and Pacific, the entire ocean is landlocked, surrounded by Russia, Norway, Greenland, Canada, and Alaska. Emptying into the Arctic Ocean are the Ob, Yenisey, and Lena rivers in Asia and the Mackenzie, Coppermine, and Back rivers in North America. The total surface area of the Arctic Ocean, including its major subdivisions—the North Polar Sea (the main portion), the Norwegian Sea, the North Sea, and the Barents Sea—is about 14 million sq km (5.4 million sq mi).