The Pacific Ocean is the largest of the Earth's oceanic divisions. Its name is derived from the Latin name Mare Pacificum, "peaceful sea", bestowed upon it by the Portuguese explorer Ferdinand Magellan. It extends from the Arctic in the north to Antarctica in the south, bounded by Asia and Australia in the west and the Americas in the east. At 169.2 million square kilometers (105.1 million square miles) in area, this largest division of the World Ocean – and, in turn, the hydrosphere – covers about 46% of the Earth's water surface and about 32% of its total surface area, making it larger than all of the Earth's land area combined."Pacific Ocean". Britannica Concise. 2006. Chicago: Encyclopædia Britannica, Inc. The equator subdivides it into the North Pacific Ocean and South Pacific Ocean. The Mariana Trench in the western North Pacific is the deepest point in the Pacific and in the world, reaching a depth of 10,911 metres (35,798 ft).

Overview

The ocean encompasses almost a third of the Earth's surface, having an area of 179.7 million square kilometres (69.4 million sq mi and 161 million cubic mi) significantly larger than Earth's entire landmass, with room for another Africa to spare Fact: date=September 2008. Extending approximately 15,500 kilometres (9,600 mi) from the Bering Sea in the Arctic to the icy margins of Antarctica's Ross Sea in the south (although the Antarctic regions of the Pacific are sometimes described as part of the circumpolar Southern Ocean), the Pacific reaches its greatest east-west width at about 5°N latitude, where it stretches approximately 19,800 kilometres (12,300 mi) from Indonesia to the coast of Colombia and Peru - halfway across the world, and more than five times the diameter of the Moon. The western limit of the ocean is often placed at the Strait of Malacca. Fact: date=September 2008 The lowest point on earththe Mariana Trenchlies 10,911 metres (35,797 ft) below sea level. Its average depth is 4,280 metres (14,000 ft).

The Pacific contains about 25,000 islands (more than the total number in the rest of the world's oceans combined), the majority of which are found south of the equator. Including partially submerged islands, the figure is substantially higher.

The Pacific Ocean is currently shrinking from plate tectonics, while the Atlantic Ocean is increasing in size, by roughly 2-3 cm/yr on 3 sides, roughly averaging 0.5 sq km a year, though global warming is counteracting this process and may even reverse the shrinkage for a while.