Pacific Ocean

views updated May 18 2018

Pacific Ocean Largest and deepest ocean in the world, covering c.33% of the Earth's surface and containing more than 50% of the Earth's seawater. The Pacific extends from the Arctic Circle to Antarctica, and from North and South America in the e to Asia and Australia in the w. The e Pacific region is connected with the Cordilleran mountain chain, and there is a narrow continental margin. The ocean is ringed by numerous volcanoes, known as the Pacific ‘Ring of Fire’. There are a number of large islands in the Pacific, most of which are in the s and w. The major ones are New Zealand, and the Japan and Malay archipelagos. The principal rivers that drain into the ocean are the Columbia in North America, and the Huang He and Yangtze in Asia. The average depth of the Pacific is 4300m (14,000ft). The greatest-known depth is that of the Challenger Deep (sw of Guam in the Mariana Trench), which has a depth of 11,033m (36,198ft). The current pattern of the Pacific is made up of two gyres: n of the Equator are the North Equatorial Current, the Kuroshio Current, the North Pacific Drift and the California Current; s of the Equator are the South Equatorial Current, the East Australian Current and the Humboldt Current. The Equatorial Counter-Current separates the two gyres. Most fishing in the Pacific is done on the continental margins. Crab, herring, cod, sardine and tuna are the principal catch. Area: c.166,000,000sq km (64,000,000sq mi).