Atlantic Ocean Wallpaper

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions; with a total area of about 106.4 million square kilometres (41.1 million square miles). It covers approximately one-fifth of the Earth's surface. The first part of its name refers to the Atlas of Greek mythology, making the Atlantic the "Sea of Atlas". The oldest known mention of this name is contained in The Histories of Herodotus around 450 BC (I 202); see also: Atlas Mountains. Another name historically used was the ancient term Ethiopic Ocean, derived from Ethiopia, whose name was sometimes used as a synonym for all of Africa and thus for the ocean. Before Europeans discovered other oceans, the term "ocean" itself was to them synonymous with the waters beyond Western Europe that we now know as the Atlantic and which the Greeks had believed to be a gigantic river encircling the world; see Oceanus.

Atlantic Ocean bottom

The principal feature of the bathymetry (bottom topography) of the Atlantic Ocean is a submarine mountain range called the Mid-Atlantic Ridge. It extends from Iceland in the north to approximately 58° South latitude, reaching a maximum width of about 1,600 kilometres (1,000 mi). A great rift valley also extends along the ridge over most of its length. The depth of water over the ridge is less than 2,700 m (8,900 ft) in most places, and several mountain peaks rise above the water and form islands. The South Atlantic Ocean has an additional submarine ridge, the Walvis Ridge.

The Mid-Atlantic Ridge separates the Atlantic Ocean into two large troughs with depths averaging between 3,700 and 5,500 metres (12,000 and 18,000 ft). Transverse ridges running between the continents and the Mid-Atlantic Ridge divide the ocean floor into numerous basins. Some of the larger basins are the Blake, Guiana, North American, Cape Verde, and Canaries basins in the North Atlantic. The largest South Atlantic basins are the Angola, Cape, Argentina, and Brazil basins.

The deep ocean floor is thought to be fairly flat, although numerous seamounts and some guyots exist. Several deeps or trenches are also found on the ocean floor. The Puerto Rico Trench, in the North Atlantic, is the deepest at 8,605 meters (28,232 ft). The Laurentian Abyss is found off the eastern coast of Canada. In the South Atlantic, the South Sandwich Trench reaches a depth of 8,428 metres (27,651 ft). A third major trench, the Romanche Trench, is located near the equator and reaches a depth of about 7,454 metres (24,455 ft). The shelves along the margins of the continents constitute about 11% of the bottom topography. Several deep channels cut across the continental rise.

Ocean sediments are composed of terrigenous, pelagic, and authigenic material. Terrigenous deposits consist of sand, mud, and rock particles formed by erosion, weathering, and volcanic activity on land and then washed to sea. These materials are found mostly on the continental shelves and are thickest off the mouths of large rivers or off desert coasts. Pelagic deposits, which contain the remains of organisms that sink to the ocean floor, include red clays and Globigerina, pteropod, and siliceous oozes. Covering most of the ocean floor and ranging in thickness from 60 to 3,300 metres (200 to 11,000 ft), they are thickest in the convergence belts and in the zones of upwelling. Authigenic deposits consist of such materials as manganese nodules. They occur where sedimentation proceeds slowly or where currents sort the deposits

Atlantic Ocean Geography

The Atlantic Ocean is bounded on the west by North and South America. In the north and northeast, it is separated from the Arctic Ocean by the Canadian Arctic Archipelago, Greenland, Iceland, Jan Mayen, Svalbard, and mainland Europe. It connects to the Arctic Ocean through the Denmark Strait, Greenland Sea, Norwegian Sea, and Barents Sea. To the east, the boundaries of the ocean proper are Europe, the Strait of Gibraltar (where it connects with the Mediterranean Sea, one of its marginal seas, and, in turn, the Black Sea), and Africa. In the southeast, the Atlantic merges into the Indian Ocean, the border being defined by the 20° East meridian, running south from Cape Agulhas to Antarctica. While some authorities show the Atlantic Ocean extending south to Antarctica, others show it as bounded at the 60° parallel by the Southern Ocean. In the southwest, the Drake Passage connects it to the Pacific Ocean. A man-made link between the Atlantic and Pacific is provided by the Panama Canal. Beside those mentioned, other large bodies of water adjacent to the Atlantic are the Caribbean Sea, the Gulf of Mexico, Hudson Bay, the Arctic Ocean, the Mediterranean Sea, the North Sea, the Baltic Sea, and the Celtic Sea.

Covering approximately 22% of Earth's surface, the Atlantic Ocean is second only to the Pacific Ocean in size. With its adjacent seas it occupies an area of about 106,400,000 square kilometers (41,100,000 sq mi); without them, it has an area of 82,400,000 square kilometres (31,800,000 sq mi). The land area that drains into the Atlantic is four times that of either the Pacific or Indian oceans. The volume of the Atlantic Ocean with its adjacent seas is 354,700,000 cubic kilometers (85,100,000 cu mi) and without them 323,600,000 cubic kilometres (77,640,000 cu mi).

The average depths of the Atlantic, with its adjacent seas, is 3,339 meters (10,936 ft); without them it is 3,926 metres (12,881 ft). The greatest depth, 8,605 metres (28,232 ft), is in the Puerto Rico Trench. The width of the Atlantic varies from 2,848 kilometers (1,770 mi) between Brazil and Sierra Leone to over 6,400 km (4,000 mi) in the south.