How Many Oceans Are There in the World?

The answer is not as straightforward as your high school geography teacher would have you believe.

On a ferry in the Atlantic Ocean232323Ni/ShutterstockHow many oceans are there in the world, you ask?

(A) 1

(B) 4

(C) 5

(D) all of the above

The answer is…D.

So congratulations! Because technically, you couldn’t have gotten this question wrong even if you tried. You see, there is only one global ocean on the planet. It covers 71 percent of the Earth’s surface. The rest of the Earth is taken up by those comparatively small islands (aka continents) known as Africa, Antarctica, Asia, Australia, Europe, North America, and South America.

Historically, this vast global ocean was divided into the following four smaller oceans:

  • Atlantic
  • Pacific
  • Indian
  • Arctic

Of these, the first three are considered the “major” oceans, and the Arctic is considered somewhat of a “lesser” ocean. But in counting how many oceans there are, no one ever actually leaves the Arctic out of it. Besides, whether major or not, all four belong to that vast, global body of water that represents 97 percent of the Earth’s water supply (a mere 1 percent of the Earth’s water is freshwater).

So where does the fifth ocean come in? At the turn of the new millennium, the International Hydrographic Organization proposed that a new ocean be recognized: the Southern Ocean, which is now recognized by the U.S. Board on Geographic Names as extending from the coast of Antarctica to the line of latitude at 60 degrees South.

And get this: the Southern Ocean isn’t even the smallest of the five oceans making up the “world ocean.” That distinction goes to the Arctic. And there’s so much more below the surface–we haven’t discovered most of the species in the oceans, but the species we have found are beautiful.

Here are a few more ocean facts that might surprise you:

  • The deepest ocean (35,837 feet) and the largest ocean is the Pacific.
  • The coldest ocean is the Southern, ranging from 28° to 50º F.
  • The first ocean to have been crossed by both ship and plane is the Atlantic.
  • The most mysterious ocean is the Arctic, because of its extensive ice coverage and inhospitable climate (the air temperature can go as low as -60º F). Speaking of a mysterious ocean, here are 14 ocean mysteries scientists can’t explain.
  • The warmest ocean is the Indian, and this has limited its ability to sustain sea life (because the high temperature inhibits the growth of phytoplankton, which is a major food source for marine life). Another reason for the lack of marine life in the Indian Ocean is its low oxygen content.

Next, read on to learn the truth behind these 30 geography facts almost everyone gets wrong.

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Lauren Cahn
Lauren Cahn is a New York-based writer whose work has appeared regularly on Reader's Digest, The Huffington Post, and a variety of other publications since 2008. She covers life and style, popular culture, law, religion, health, fitness, yoga, entertaining and entertainment. Lauren is also an author of crime fiction; her first full-length manuscript, The Trust Game, was short-listed for the 2017 CLUE Award for emerging talent in the genre of suspense fiction.