All of Earth’s oceans are connected, but different parts have different names. The Old Farmer’s Almanac for Kids  takes a look at each name and its origin!
The Pacific Ocean (the largest) was named by Portuguese explorer Ferdinand Magellan in 1520. He was leading a fleet of ships from Spain, in search of a western route to the Spice Islands. In late November, his three remaining ships sailed into what Magellan described as a “beautiful, peaceful ocean.” Its name became Pacific, from the Latin word for peaceful.
The Atlantic Ocean is named after the Greek mythological figure Atlas, who was said to be strong and to carry the world on his back.
The Southern Ocean, once called the Antarctic Ocean, surrounds the continent of Antarctica and was renamed in 1999. This ocean’s large, strong, circumpolar current carries 150 times more water than all of the world’s rivers combined. When it flows near the strong currents in the Atlantic, Pacific, and Indian oceans, it mixes with their waters. The Southern Ocean’s fierce winds and storms, sea ice, and icebergs have made its waters the least explored in the world. Its currents, sea ice, and cold waters can affect climate everywhere.
The Arctic Ocean (the smallest) is named for the region around the North Pole. The word “arctic” comes from the ancient Greek arktos, or bear, for the bear constellations Ursa Major and Ursa Minor, which include Polaris, the North Star.
The Indian Ocean is named for the subcontinent of India, the name of which in turn comes from the Indus River. Early Persian explorers could not properly say the “s” in sindhu, the Sanskrit word for “river.” Their pronunciation of “hindu” later became “indos” and “indus” to invading Greeks and Romans, respectively.