Tina Erickson, age 13, of Willingboro, N.J., for her question:
WHO NAMED THE ATLANTIC OCEAN?
Ancient Romans named the Atlantic Ocean after the Atlas Mountains. Rising at the western edge of the Mediterranean Sea, these mountains marked the limits of the world as it was then known. Atlantic probably referred to the fact that the ocean lay beyond the Atlas range.
Although it ranks second in size to the Pacific Ocean, the Atlantic is regarded as the most important ocean for commerce since the world's leading and largest industrial countries lie along its coasts.
The Atlantic covers almost a third of the world's water surface and over a fifth of the entire surface of the world. The ocean's area is more than 41 million square miles.
Stretching from the Arctic ocean on the north to the Antarctic Ocean on the south, the Atlantic is about 9,000 miles long. The widest part, a distance of 4,150 miles, lies between Florida and Spain.
The eastern coastline of the Atlantic is 31,000 miles long while the western coastline measures 55,000 miles.
The ocean's average depth is about 14,000 feet. Water is less than 500 feet deep along the 300 mile wide continental shelf off North America, southern South America and most of Europe. Deep underwater valleys, however, go down to more than 18,000 feet. The deepest spot is called the Milwaukee Deep and it is 28,374 feet below the surface.
Phoenician traders were the first to explore the Atlantic. They did this about 700 B.C. They ventured through the Strait of Gibralter to trade along the coast of Spain and Morocco. They went as far south as southern Africa and as far north as the British Isles by about 600 B.C.
Vikings started exploring the Atlantic about A.D. 800. During the next 200 years they colonized Greenland and Iceland and most likely reached North America.
During the 1300s and 1400s, exploration of the Atlantic increased very quickly. In 1492, Christopher Columbus proved that ships could travel safely to distant places.
During the early 1500s, explorers from England, France, Portugal and Spain sailed through most of the Atlantic Ocean.
The first major study of the Atlantic Ocean's floor was made by oceanographers aboard the British research ship Challenger in 1873 and 1876. They reported in detail on the many deep sea plants and animals they found.
It wasn't until the 1930s that oceanographers started to measure the depth of the Atlantic with sonar, an electronic detecting device based on sound. Previously, ocean depths had been measured by lowering a cable of known length to the bottom.
By the mid 1960s, sonar and other electronic devices let map makers chart most of the Atlantic's floor.
Researchers on the United States research ship Glomar Challenger conducted the Deep Sea Drilling Project during the 1960s. They drilled 100 holes into the Atlantic floor and obtained fossils and minerals from more than 3,000 feet beneath the seabed.