How many oceans does the Earth have?

Today the Earth is generally said to have five oceans. They are the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Arctic Ocean, and the Southern Ocean. Together these great bodies of salt water cover the majority of our planet's surface. In truth, all of them are connected, forming one continuous global ocean, but for convenience we divide it into these five named regions.

For a long time, most people learned that there were only four oceans: the Pacific, Atlantic, Indian, and Arctic. The fifth, the Southern Ocean, is a recent addition to the list. It is the body of water that surrounds the continent of Antarctica. Although sailors and scientists had recognized it for many years, it was only in recent decades that major organizations officially recognized the Southern Ocean as a distinct, fifth ocean.

The Southern Ocean is special because it is not defined by surrounding land the way other oceans are. Instead, it is defined by a powerful current. A strong, cold current called the Antarctic Circumpolar Current flows in a continuous ring all the way around Antarctica. This current creates a real boundary in the water itself, with conditions inside it that differ from the oceans further north. That distinct nature is the main reason it earned recognition as its own ocean.

The five oceans are very different in size. The Pacific Ocean is by far the largest, so vast it covers roughly a third of the entire surface of the Earth. At the other end of the scale, the Arctic Ocean is the smallest and also the shallowest of the five. The Atlantic and Indian Oceans fall in between, while the Southern Ocean rings the bottom of the globe around Antarctica. Whether the count is four or five often simply depends on how recently someone learned their geography.

This article was written using information from Wikipedia.