The Pacific Ocean

• The largest body of water on Earth is the Pacific Ocean; it covers more than one-third of the Earth's surface -- around 155 million square kilometers. The coastlines of all the nations that border the Pacific are about 135,663 kilometers long. The Pacific Ocean stretches from the Southern Ocean in the south, Australia and Asia in the east, the Arctic Ocean in the north and the Americas in the west. The Pacific Ocean received its name from the explorer Ferdinand Magellan who named the body of water the "Mar Pacifico," which means "peaceful sea" in Portuguese.
  
  

The Atlantic Ocean

• The second-largest body of water is the Atlantic Ocean. It covers a total of 106.4 million square kilometers and extends between the Americas and Eurasia and Africa in the west and east and the Southern Ocean and the Arctic Ocean to the south and north, respectively. 20 percent of the Earth's surface is covered by the Atlantic. The importance of the Atlantic Ocean increased during European exploration in the 15th and 16th centuries when explorers sought a trade route to India.
  
  

The Indian Ocean

• Covering 73.5 million square kilometers, the Indian Ocean is the Earth's third-largest body of water. It borders Asia to the east, The Indian subcontinent and parts of the Middle East to the north, Africa to the west and the Southern Ocean to the south. The Indian Ocean has been used for trade for nearly 3000 years, ever since ancient Mesopotamian cultures traded with Africa. Indonesians also crossed the Indian Ocean to settle in Madagascar, and Europeans used the body of water as they traveled from Europe to India to trade goods.
  
  

The Southern Ocean

• The Southern Ocean is a body of water which has the distinction of being the only ocean to completely encircle Antarctica. It covers a surface area of 20.3 million square kilometers, making it the fourth-largest body of water on Earth. Damage to the ozone layer over Antarctica has reduced the ocean's plankton population by 15 percent; this atmospheric "hole" has also caused genetic problems in marine life in the Southern Ocean.
  
  

The Arctic Ocean

• The Arctic Ocean is the fifth-largest ocean on Earth with a surface area of 14 million square kilometers; it is surrounded by North America, Eurasia and Greenland. During the summer months, the ocean can shrink up to 50 percent of its normal size as ice melts and flows into the Atlantic and Pacific Oceans to the south. The Arctic Ocean consists primarily of floating icebergs and stationary glaciers of ice.