Mark Choate, age 9, of Des Moines, Iowa, for his question:
WHAT IS THE DIFFERENCE BETWEEN A SEA AND AN OCEAN?
Sometimes our use of language can be confusing. The words "sea" and "ocean" are good examples of this, since they are frequently used interchangeably. Technically, however, there is a big difference.
An ocean is a major body of water. The word "ocean" is included in the names of only five bodies of water in the world Atlantic, Pacific, Indian, Arctic and Antarctic. These are the earth's major bodies of salt water which extend between the continents. A sea, on the other hand, is much smaller than an ocean, but since it adjoins an ocean, or may be within an ocean, the confusion is only natural.
A sea can have rather indefinite borders, such 'as the Caribbean Sea, the Barents Sea and the Philippine Sea. Or it can be strictly defined, such as the Red Sea or the Black Sea.
Of the five oceans, the Pacific is by far the largest, covering some 64 million square miles. Also the deepest ocean, its average depth is about 13,000 feet, and its greatest known depth is 37,782 feet. About half the size of the Pacific, the Atlantic Ocean extends from the Arctic to the Antarctic regions, and from Europe and Africa on the east, to the Americas on the west.
The Indian Ocean, the third largest, lies south of the equator and forms two large indentations in the southern coast of Asia the Arabian Sea and the Bay of Bengal. The Antarctic Ocean, which some geographers consider merely part of the southern regions of the Atlantic, Indian and Pacific oceans, varies in width from 700 miles to 2,400 miles. The smallest ocean, the Arctic, encircles the North Pole and is about a tenth the area of the Pacific. Many geographers consider the Arctic a part of the Atlantic rather than aseparate body of water.
The five oceans cover about 70 percent of the earth's surface. When we include the seas, this becomes almost three¬quarters or 75 percent. The largest sea is the 1,145,100¬square mile Mediterranean, which is nearly landlocked between Europe, Asia and Africa. Connected in the west to the Atlantic Ocean by the narrow Strait of Gibraltar, its eastern outlet, to the Red Sea, is by way of the Suez Canal.
One of the largest, most beautiful seas in the world is the Caribbean. An extension of the Atlantic Ocean, it covers 750,000 square miles and is bounded by the coasts of Central and South America and the major islands of the West Indies. Named for the Carib Indians, who once lived on the smaller islands, the sea is famous for its blue crystal clear water.
The Sargasso Sea lies in the North Atlantic Ocean and no land boundaries of any kind mark off this body of water from the rest of the open ocean. Set apart only by the presence of marine plants which float on its surface, it derives its name from sargaco, one of the Portuguese words for seaweed. Early seafarers spread legends and myths about the region, establishing it as a monster ridden, seaweed¬blanketed trap from which no ship could escape. Of course, today the truth is known the Sargasso Sea's plant life may be dense, but it does not interfere with the movements of a ship.