Atlantic
Ocean, the second largest of the earth's four
oceans and the most heavily traveled. Only the Pacific Ocean is larger. It covers about twice the
area of the Atlantic Ocean. The Atlantic is
divided into two nominal sections: The part north of the equator is called the
North Atlantic; the part south of the equator, the South
Atlantic. The ocean's name is derived from Atlas, one of the
Titans of Greek mythology.
I BOUNDARIES AND SIZE The
Atlantic Ocean is essentially an S-shaped north-south channel, extending from
the Arctic Ocean in the north to the Antarctic continent in the south and
situated between the eastern coast of the American continents and the western
coasts of Europe and Africa. The Atlantic Ocean proper has a surface area of
about 82 million sq km (about 31,660,000 sq mi). Including its marginal
seas-the Gulf of Mexico-Caribbean Sea, the Arctic Ocean, and the North, Baltic,
Mediterranean, and Black seas-the total area is about 106,190,000 sq km (about
41 million sq mi).
The boundary between the North Atlantic and the
Arctic Ocean is arbitrarily designated as lying along a system of submarine
ridges that extend between the land masses of Baffin Island, Greenland, and Scotland. More
clearly defined is the boundary with the Mediterranean Sea at the Strait of Gibraltar
and with the Caribbean Sea along the arc of the Antilles.
The South Atlantic is arbitrarily separated from the Indian Ocean on the east
by the 20° east meridian and from the Pacific on the west along the line of
shallowest depth between Cape Horn and the Antarctic
Peninsula.
II MARINE RESOURCES The
Atlantic Ocean contains some of the world's most productive fisheries, located
on the continental shelves and marine ridges off the British Isles, Iceland,
Canada (especially the Grand Banks off Newfoundland), and the northeastern
United States. Upwelling areas, in which the nutrient-rich waters of the ocean
depths flow up to the surface, as in the vicinity of Walvis Bay off
southwestern Africa, also have abundant sea
life. Herring, anchovy, sardine, cod, flounder, and perch are the most
important commercial species. Tuna is taken off northwestern Africa and
northeastern South America in increasing
numbers. The catch per unit area is much higher in the Atlantic
than in the other oceans.
A remarkable example of plant life is found in the
Sargasso Sea, the oval section of the North Atlantic lying between the West
Indies and the Azores and bounded on the west and north by the Gulf Stream. Here extensive patches of brown gulfweed (Sargassum)
are found on the relatively still surface waters.
Actively mined mineral resources in the Atlantic include titanium,
zircon, and monazite (phosphates of the cerium metals), off the eastern coast
of Florida, and tin and iron ore, off the
equatorial coast of Africa. The continental
shelves and slopes of the Atlantic are
potentially very rich in fossil fuels. Large amounts of petroleum are already
being extracted in the North Sea and in the Caribbean Sea-Gulf of Mexico region; lesser amounts are extracted off
the coast of Africa in the Gulf
of Guinea.
