Atlantic Ocean

Atlantic Ocean, the name given to that vast body of water that separates the Old World from the New, its north and south limits being the Arctic and Antarctic circles. It thus has a length of 9,000, an average breadth of 2,700, a shore line of over 50,000 miles, and an area of 25,000,000 square miles. The widest stretches from land to land are just under 4,000 miles between Florida and Morocco, or Cape Horn and the Cape of Good Hope, and the narrowest breadth, between Norway and Greenland, is 900 miles, whilst from Cape Rocca to Sierra Leone the distance is 1,700 miles. The depth averages from three to five miles. Off St. Thomas soundings of 23,250 feet have been taken, but south of the Newfoundland Bank there seems to be a much deeper depression. Along the "Telegraphic Plateau" from Cape Clear to Cape Race the mean depth is no more than 11,000 or 12,000 feet, and the ocean becomes shallower as the Pole is approached. This fluid mass is influenced by two great surface currents, viz. the Gulf Stream, which issues from the Gulf of Mexico, at a temperature of from 10 to 30 degrees higher than the surrounding water, and strikes in a north-east direction, passing between Iceland and Norway, and the Equatorial Current, sweeping in the opposite direction from the African coast to Cape St. Roque, where it divides, one half entering the Caribbean Sea, and the other half taking a southerly direction along the Brazilian coast. A minor current, really a branch of the Gulf Stream, sets from the Azores towards Africa, and, curving round Cape Palmas, reaches the Bight of Benin. It is called the Guinea Current. Cold streams issuing from Davis's Strait and from the Polar Sea meet the Gulf Stream off the American coast in about 50° N. lat. and passing under it find their way to the equator. In the South Atlantic below Cape Horn a counter current to the Equatorial Current has a constant easterly direction. A large space of still water called the Sargasso Sea is enclosed between the Gulf Stream and the Equatorial Current. It is close packed with sea-weeds, especially with the Sargassum bacciferum, from which it gets its name. The Atlantic, apart from being affected by constant, periodical, and local winds, is liable to heavy gales in the temperate zones, and to cyclones and hurricanes at the equator. Fogs are prevalent at the points where the Gulf Stream meets colder currents, and icebergs drift as far south as 44° N., whilst in the southern hemisphere their range extends as high as the latitude of the Cape. Waves acquire a greater height and mass in this ocean than in any other. Off the Cape of Good Hope they are sometimes 40 feet high and a quarter of a mile broad. In the North Atlantic it is seldom that they exceed 25 feet.