Total area: 165,384,000 km2; includes Arafura Sea, Banda Sea, Bellingshausen Sea, Bering Sea, Bering Strait, Coral Sea, East China Sea, Gulf of Alaska, Makassar Strait, Philippine Sea, Ross Sea, Sea of Japan, Sea of Okhotsk, South China Sea, Tasman Sea, and other tributary water bodies

Comparative area: slightly less than 18 times the size of the US; the largest ocean (followed by the Atlantic Ocean, Indian Ocean, and Arctic Ocean); covers about one-third of the global surface; larger than the total land area of the world

Coastline: 135,663 km

Climate: the western Pacific is monsoonal--a rainy season occurs during the summer months, when moisture-laden winds blow from the ocean over the land, and a dry season during the winter months, when dry winds blow from the Asian land mass back to the ocean

Terrain: surface in the northern Pacific dominated by a clockwise, warm water gyre (broad, circular system of currents) and in the southern Pacific by a counterclockwise, cool water gyre; sea ice occurs in the Bering Sea and Sea of Okhotsk during winter and reaches maximum northern extent from Antarctica in October; the ocean floor in the eastern Pacific is dominated by the East Pacific Rise, while the western Pacific is dissected by deep trenches; the world's greatest depth is 10,924 meters in the Marianas Trench

Natural resources: oil and gas fields, polymetallic nodules, sand and gravel aggregates, placer deposits, fish

Environment: endangered marine species include the dugong, sea lion, sea otter, seals, turtles, and whales; oil pollution in Philippine Sea and South China Sea; dotted with low coral islands and rugged volcanic islands in the southwestern Pacific Ocean; subject to tropical cyclones (typhoons) in southeast and east Asia from May to December (most frequent from July to October); tropical cyclones (hurricanes) may form south of Mexico and strike Central America and Mexico from June to October (most common in August and September); southern shipping lanes subject to icebergs from Antarctica; occasional El Nino phenomenon occurs off the coast of Peru when the trade winds slacken and the warm Equatorial Countercurrent moves south, which kills the plankton that is the primary food source for anchovies; consequently, the anchovies move to better feeding grounds, causing resident marine birds to starve by the thousands because of their lost food source

Note: the major choke points are the Bering Strait, Panama Canal, Luzon Strait, and the Singapore Strait; the Equator divides the Pacific Ocean into the North Pacific Ocean and the South Pacific Ocean; ships subject to superstructure icing in extreme north from October to May and in extreme south from May to October; persistent fog in the northern Pacific from June to December is a hazard to shipping; surrounded by a zone of violent volcanic and earthquake activity sometimes referred to as the Pacific Ring of Fire

NOTE: The information regarding Pacific Ocean on this page is re-published from the 1990 World Fact Book of the United States Central Intelligence Agency. No claims are made regarding the accuracy of Pacific Ocean Geography 1990 information contained here. All suggestions for corrections of any errors about Pacific Ocean Geography 1990 should be addressed to the CIA.