P-2+Ocean+Basins

Hydrologically, an oceanic basin may be anywhere on [|Earth] that is covered by [|seawater], but geologically ocean basins are large [|geologic basins] that are below [|sea level].



Ocean basins can be described as saucer-like depressions of the seabed. They vary in size from relatively minor features of the continental margin to vast structural divisions of the deep ocean. The largest ocean basins are 3 to 5 kilometers (2 to 3 miles) deep and stretch from the outer margins of the continents to the mid-ocean ridges. Ocean basins cover approximately 71 percent of Earth's surface or about 361 million square kilometers (140 million square miles). Their average depth is 5,000 meters (16,000 feet), and the total volume is about 1.35 billion cubic kilometers (322 million cubic miles). There are five major subdivisions of the world ocean: the Pacific Ocean, Atlantic Ocean, Indian Ocean, Southern Ocean, and Arctic Ocean. The Pacific, Atlantic, and Indian Oceans are conventional ocean basins and are bounded by the continental masses or by ocean ridges and currents; they merge below 40° South latitude in the Antarctic Circumpolar current, or west Wind Drift, at the Southern (or Antarctic) Ocean. In the North Polar Region, the nearly circular Arctic Ocean, almost landlocked except between Greenland and Europe, is considered the fifth ocean subdivision.

Read more: [|Ocean Basins - sea, depth, oceans, temperature, important, largest, system, marine, Pacific]