The Atlantic Ocean was named long„ long in the past, before the New World was discovered. The ancient Mediterranean people were very scared of the vast ocean beyond the Straits of Gibraltar, which they called the Pillars of Hercules. Some people think that the ocean was named for the Atlas Mountains in North Africa. Others say that it was named for the island of Atlantis, which the ancients thought to be somewhere in the western ocean.
The Pacific Ocean was named in 1520 by Ferdinand Magellan on his voyage around the world. To Magellan it seemed Pacific, or peaceful, after the wild gales of the Atlantic. The Indian Ocean is named, of course, for the great subcontinent of India which dips down into its waters. The Arctic Ocean is named for the north polar regions and the Antarctic Ocean for the opposite, or south polar regions.