The Pacific Ocean is the largest of the Earth's oceanic divisions. 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 kilometres (65.3 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. The equator subdivides it into the North Pacific Ocean and South Pacific Ocean.