The Atlantic Ocean
Size and Shape
The total area of the Atlantic Ocean is 82,441,500 sq km. It is thus half the size of the Pacific Ocean and accounts for nearly 1/6th part of the earth’s surface area. It extends from Greenland in the north to the Antarctic continent in the south. It resembles the shape of letter ‘S’. On the west, it is bounded by the Americas and on the east by Europe and Africa. In the south, it is open and may be considered to extend up to the continent of Antarctica. In the north, however, Greenland, Iceland and other smaller islands appear to enclose it.
The Atlantic Ocean has vast continental shelf and it spreads all along the coast. But its width varies from 80–110 km o the coast of Africa to 250–400 km other coast of North East America and north-west Europe. The most striking feature of the Atlantic Ocean is the presence of the mid-Atlantic Ridge. It extends from Iceland in the north to Bouvet Island in the south paralleling the ‘S’ shape of the ocean itself. It is about 14,000 km long and 4,000 m high. It divides the Atlantic Ocean into two deeper basins on either side. It becomes quite broad at 55° N and is known as Telegraph Plateau. Romanche deep near the equator divides this ridge into two parts. The northern part is known as Dolphin Ringe while the southern part is called Challenger Ridge.
Although it is a submarine ridge, yet some of its peaks project out of water in the form of islands. Azores, Pico and Cape Verde islands are its main examples. St. Paul near the equator has very sharp peak. Ascension, Tristan-da-Cunha, St. Helena and Gough and Bauvet islands in the south Atlantic are of volcanic origin. Bermuda is a coral island.
There are many deep areas between the coasts and the ridge of the Atlantic Ocean which are known as basins. They are usually 4,000 metres deep. Important basins of the Atlantic Ocean are the Labrador Basin, North American Basin, Guiana Basin, Brazil Basin, Argentine Basin, West European Basin, Angola Basin, and Agulhas Basin.
The Atlantic Ocean lacks in islands. In the North Atlantic, there are Newfoundland, British Isles and West Indies. In south Atlantic only Falkland islands are worth mentioning. Some smaller islands appear on the Mid-Atlantic Ridge which have already been discussed.
Troughs and Trenches
The Atlantic Ocean also lacks in troughs and trenches. According to Murray, there are 19 deeps with depth exceeding 5,500 metres. Only two are more than 7,000 metres deep. North Cayman and Puerto Rico are the two troughs and Romanche and South Sandwich are the two trenches in the Atlantic Ocean.
There are many marginal seas on the both sides of the Atlantic Ocean. Most of them are located on the continental shelf. Important seas are Ba Bay, Hudson Bay, North Sea, Baltic Sea, Gulf of Mexico, Mediterranean Sea, and Caribbean Sea. All of them are in the North Atlantic.