By – Jayanarayan Jayakumar Jithin Jose Shijo John Jacob Basim John P JacobIMPORTANCE OF OCEANS
OCEANS • AN OCEAN IS A MAJOR BODY OF SALINE WATER, AND A PRINCIPAL COMPONENT OF THE HYDROSPHERE. APPROXIMATELY 71% OF THE EARTHS SURFACE IS COVERED BY OCEAN, A CONTINUOUS BODY OF WATER THAT IS CUSTOMARILY DIVIDED INTO SEVERAL PRINCIPAL OCEANS AND SMALLER SEAS.
THE MAJOR OCEANS• The major oceanic divisions are defined in part by the continents, various archipelagos, and other criteria. These divisions are (in descending order of size):• Pacific Ocean, which separates Asia and Australia from the Americas• Atlantic Ocean, which separates the Americas from Eurasia and Africa• Indian Ocean, which washes upon southern Asia and separates Africa and Australia• Southern Ocean, sometimes considered an extension of the Pacific, Atlantic and Indian Oceans,  which encircles Antarctica.• Arctic Ocean, sometimes considered a sea of the Atlantic, which covers much of the Arctic and washes upon northern North America and Eurasia.
IMPORTANCE• Throughout history humans have been directly or indirectly influenced by the oceans. Ocean waters serve as a source of food and valuable minerals, as a vast highway for commerce, and provide a place for recreation. Increasingly, people are turning to the oceans for their food supply either by direct consumption or indirectly by harvesting fish that is then processed for livestock feed. It has been estimated that as much as 10% of human protein intake comes from the oceans. Nevertheless, the food-producing potential of the oceans is only partly realized. Other biological products of the oceans are also commercially used.
SHIPPING ROUTES:• The oceans provide convenient transport routes - which we take full advantage of. Around 90% of all trade between countries is carried by ships. These transport everything from food and fuel to construction materials, chemicals, and household items.
OXYGEN:• It’s not just ocean life that depends on phytoplankton. These tinymarine plants are estimated to produce over half the oxygen that we, andall other land animals, breathe. CO2 SINK: Ocean waters have the capacity to absorb vast amounts of the greenhouse-warming gas carbon dioxide (CO2), and thus have helped to buffer human-caused global warming and climate change. Indeed, nearly half the CO2 produced by human activities in the last 200 years has dissolved into the ocean.Phytoplankton also lock CO2 away. Like land plants, these microscopic algae use CO2 to grow. When they die, this CO2 sinks as organic matter to the bottom of the ocean, keeping it out of the atmosphere.
TEMPERATURE AND WEATHER CONTROL:• The surface layer of the ocean absorbs over half the heat reaching the Earth from the sun. By distributing this heat around the world, ocean currents - which flow for thousands of kilometres, both at the surface and far below - are extremely important in determining the climate of the world’s continents. For example, the Gulf Stream carries warm water from the Gulf of Mexico all the way to western Europe. This water warms the air above, which is then blown across to the land. As a result, northwest Europe is much warmer than other lands at the same latitude. Hurricanes and cyclones can be destructive when they hit land, but these tropical storms also help distribute heat from the tropics to higher latitudes through the atmosphere.
Water cycle: THE OCEANS ARE ALSO AN INTEGRAL PART OF THE WATER CYCLE. VAST AMOUNTS OF WATER EVAPORATE FROM THE OCEAN SURFACE, RISING INTO THE ATMOSPHERE AS WATER VAPOUR. WHEN THIS VAPOR COLLIDES WITH COLDER AIR, IT CONDENSES TO FORM CLOUDS AND RAIN.
LIFE• A wide variety of organisms, including algae, jellyfish, lobsters, fish, sea turtles, and whales, live in the ocean. Many of these organisms are threatened by pollution. Among the causes of this pollution are the discharge of municipal and industrial wastes, and the accidental spilling of oil from tankers and offshore oil rigs. A number of laws and international agreements ban or restrict the disposal of various pollutants into the ocean.
FOR MORE INFORMATION ,VISIT-• http://www.factmonster.com/ce6/sci/ A0860103.html• http://www.youtube.com/watch?v=83 UwUQxlqyI• http://wwf.panda.org/about_our_eart h/blue_planet/open_ocean/ocean_im portance/