|Lutgens, Frederick. Essentials of Geology. New York: MacMillan, 1992: 269.||"… approximately 360 million square kilometers (140 million square miles), or 71 percent, are represented by the oceans and mariginal seas."||360,000,000 km2|
|"Oceans and Seas." Academic American Encyclopedia. Vol. 14. Danbury, CT: Grolier, 1996: 325-332.||[I added up the numbers from a table in this source to obtain the result.]||361,060,000 km2|
|Erickson, Jon. The Mysterious Oceans. Blue Ridge Summit: Tab Books, 1988: vii.||"About 70 percent of the surface of the Earth is covered by oceans"||357,000,000 km2|
|Soule, Gardner. Wide Oceans. New York: Rand McNally, 1970: 15.||"The mathematical answer is approximately 139 million square miles."||360,008,310 km2|
|"Oceans." The World Book. Vol. 14. Chicago: World Book, 1997: 650-666.||"Ocean is the great body of water that covers more than 70 percent of the Earth's surface."||357,000,000 km2|
The planet Earth is a planet of oceans. The total area of the Earth is approximately 510 million square kilometers and the oceans cover about 71 percent of the Earth's surface, which is about 360 million square kilometers.
There are a total of 5 oceans, and they are the Arctic, Pacific, Atlantic, Indian, and the Antarctic Ocean. Out of these five, there are three major oceans, the Atlantic, Pacific, and the Indian Ocean. They account for 90 percent of the area covered by oceans. The Pacific Ocean is the largest of oceans, its area is 181 million square kilometers, which covers nearly a third of the Earth's surface. The Atlantic Ocean is the second largest, covering 94 million square kilometers, and the Indian Ocean is the third largest, covering about 74 million square kilometers.
The oceans' tremendous presence causes it to have a huge effect on the planet and our civilization. It is greatly responsible for the climate of the Earth. It regulates air temperature and supplies moisture for rainfall. The ocean also provides us with food, energy, minerals, and a cheap method of transportation. Without the oceans, the Earth wouldn't be able to sustain life.
Eric Cheng -- 1997