Prepare a map of Atlantic Ocean floor mentioning ocean basins and the mid-Atlantic ridge.

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The Atlantic Ocean covers about l/6th of the earth's total surface. On the east it is bounded by Europe and Africa, on the west by both North America and South America, in the north by Greenland, Iceland and other smaller islands and in the south it is open upto Antarctica.

Continental Shelf : Continental shelf occurs all around the Atlantic Ocean but it varies in width. It is wider in the north than in the south.

Seas : There are numerous marginal seas on both Sides of the Atlantic Ocean. Most of them are located in shelves like Hudson Bay, the Baltic Sea and the North Sea.

Fig. 13.9 : Topographic Features of the Atlantic Ocean.

Ridge : Special feature of the Atlantic Ocean is the Mid-Atlantic Ridge. It extends from north to south parallel to the ‘S’ shape of the ocean itself. It divides the Atlantic into two deeper basins on either side. The ridge is about 1400 km long and about 4000 metres high. The slopes on both sides are very gentle. It rises as a series of steps.

Islands : The ridge has many peaks projecting themselves above the water surface. Such a island is Pico Island of Azores. Cape Verde Island of Bermuda is a coral island. Ascension, Tristan Dacunha, St. Helena, Gough are volcanic islands.

Trough and Trenches : The Atlantic Ocean lacks in trough and trenches. North Gayman and Puerto Rico are the two troughs and Ramanche and South Sandwich are the two trenches in the Atlantic Ocean.