An ocean (from Greek Ωκεανός, Okeanos (Oceanus)) is a large body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface (an area of some 361,000,000 square kilometres (139,000,000 sq mi)) is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.
More than half of this area is over 3,000 metres (9,800 ft) deep. Average oceanic salinit...
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An ocean (from Greek Ωκεανός, Okeanos (Oceanus)) is a large body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface (an area of some 361,000,000 square kilometres (139,000,000 sq mi)) is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.
More than half of this area is over 3,000 metres (9,800 ft) deep. Average oceanic salinity is around 35 parts per thousand (ppt) (3.5%), and nearly all seawater has a salinity in the range of 30 to 38 ppt. Scientists estimate that 230,000 marine life forms of all types are currently known, but the total could be up to 10 times that number.
Though generally described as several 'separate' oceans, these waters comprise one global, interconnected body of salt water often referred to as the World Ocean or global ocean. This concept of a continuous body of water with relatively free interchange among its parts is of fundamental...
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