The Pacific Ocean is Earth’s largest ocean, covering more area than all of the planet’s land combined.
The Pacific stretches from Asia and Australia to the Americas, and from the Arctic Ocean southward to the Southern Ocean. Its name comes from the Portuguese navegador Ferdinand Magellan, who called it Mar Pacífico, meaning “peaceful sea,” after encountering relatively calm waters in 1520. Conditions across the ocean are not always peaceful, however, because it contains major storm, earthquake, and volcanic zones.
The Pacific includes the Mariana Trench, whose Challenger Deep is the deepest known point in Earth’s oceans. Much of its rim forms the Pacific Ring of Fire, a zone of frequent earthquakes and volcanoes associated with tectonic plate boundaries. The ocean also contains thousands of islands, including the many island groups of Polynesia, Micronesia, and Melanesia.