- Education and Science
Oceans of the world
The 5 oceans
The world's oceans and seas together cover nearly 71% of the earth's surface. Since the oceans are a continuous body of water on the Earth's surface, it is not possible to have clearly demarcated borders between one ocean and another or any other adjacent water body for that matter. For the convenience of oceanographers and for other practical purposes like study and research, it is generally recognized that the huge body of water on the Earth's surface is divided into five oceans the Pacific Ocean, the Atlantic Ocean, and the Indian Ocean, the Arctic ocean and the southern ocean. The Pacific Ocean is the largest of the world's five oceans, followed by the Atlantic Ocean, Indian Ocean, Southern Ocean, and Arctic Ocean.
The Pacific Ocean
The Pacific Ocean is the largest ocean in the world. It is the body of salt water extending from the Antarctic region in the south to the Arctic circle in the north and lying between the continents of Asia and Australia on the west and North and South America on the east.
It occupies about one-third of the surface of the earth and is twice the size of the Atlantic Ocean and more than the whole land area of the globe. The area of pacific ocean is approximately 165.557 million sq km. It includes Bali Sea, Bering Sea, Bering Strait, Coral Sea, East China Sea, Gulf of Alaska, Gulf of Tonkin, Philippine Sea, Sea of Japan, Sea of Okhotsk, South China Sea, Tasman Sea, and other tributary water bodies.
The natural resources found in this ocean are oil and gas, polymetallic nodules, sand and gravel aggregates, placer deposits and fish. Many marine species are becoming endangered, which include the dugong, sea lion, sea otter, seals, turtles, and whales. There is also tremendous oil pollution in Philippine Sea and South China Sea which are a threat to the sea life.
There are many ports and terminals in the pacific ocean, some of which are Bangkok in Thailand, Hong Kong in China, Kao-hsiung in Taiwan, Los Angeles in US, Manila in Philippines, Pusan in South Korea, San Francisco in US, Seattle in US, Shanghai in China, Singapore, Sydney in Australia, Vladivostok in Russia, Wellington in New Zealand and Yokohama in Japan
The Pacific Ocean is a major contributor to the world economy. It provides low-cost sea transportation between East and West, large fishing grounds, offshore oil and gas fields, minerals, and sand and gravel for the construction industry.
The Pacific Ocean is surrounded by a zone of violent volcanic and earthquake activity sometimes referred to as the "Pacific Ring of Fire" and is also subject to to tropical cyclones. The Equator divides the Pacific Ocean into the North Pacific Ocean and the South Pacific Ocean.
Mariana Trench, is the deepest seafloor in the world with a depth of 10,911 m. It is located just east of the Mariana Islands. The Mariana Trench is an arc-shaped valley extending for 2,550 km. The Mariana is one of many deepwater ocean trenches formed by the geologic process of subduction.
Interesting Facts About Pacific Ocean
- Pacific Ocean covers about 46% of the Earth's water surface and about 32% of its total surface area.
- Pacific Ocean is larger than all of the Earth's land area combined.
- Mariana Trench in the western North Pacific, at a depth of 10,911 m, is the deepest point in the Pacific Ocean as well as the world. Its depth is more than the height of Mt.Everest.
- The average depth of Pacific Ocean is 4,280 meters (14,000 ft).
- There are more than 25,000 islands in the Pacific Ocean, the number being more than count of islands in the rest four oceans.
- The water temperatures in Pacific Ocean range from freezing in the pole-ward areas to about 30 °C (86 °F) near the equator.
- Pacific Ocean is the largest, the deepest as well as the oldest ocean in the world.
- The island of New Guinea, the second largest island in the world, is the largest landmass entirely within the Pacific Ocean.
- There are basically four types of islands in the Pacific Ocean - continental islands, high islands, coral reefs, and uplifted coral platforms.
- Pacific Ocean is connected with Arctic Ocean by the Bering Strait and with Atlantic Ocean by Drake Passage, Straits of Magellan and Panama Canal.
- Almost the entire rim of the Pacific basin is ringed with volcanoes and earthquake areas.
- The coral islands in Pacific Ocean, called atolls, are formed on the top of submerged volcanoes by coral polyps.
- Pacific Ocean is connected with Indian Ocean by passages in the Malay Archipelago and between Australia and Antarctica.
- The Great Barrier Reef in Pacific Ocean, off the coast of Australia, is the longest reef in the world.
The Atlantic Ocean
The Atlantic Ocean is the second largest ocean in the world. Hurricanes often form out in the open ocean during the summer and fall. The natural resources are gas and oil fields. The Atlantic Ocean has some of the most heavily trafficked sea routes.
The area of atlantic ocean is 76.762 million sq km which includes Baltic Sea, Black Sea, Caribbean Sea, Davis Strait, Denmark Strait, part of the Drake Passage, Gulf of Mexico, Labrador Sea, Mediterranean Sea, North Sea, Norwegian Sea, almost all of the ScotiaSea, and other tributary water bodies
The natural resources are oil and gas fields, fish, marine mammals like seals and whales, sand and gravel aggregates, placer deposits, polymetallic nodules and precious stones
There are many endangered marine species which include the manatee, seals, sea lions, turtles, and whales, the reason behind this being drift net fishing which is hastening the decline of fish stocks and municipal sludge pollution off eastern US, southern Brazil, and eastern Argentina. There is also oil pollution in Caribbean Sea, Gulf of Mexico, LakeMaracaibo, Mediterranean Sea, and North Sea; industrial waste and municipal sewage pollution in Baltic Sea, North Sea, and Mediterranean Sea
The ports and terminals in this sea are Alexandria in Egypt, Algiers in Algeria, Antwerp in Belgium, Barcelona in Spain, Buenos Aires in Argentina, Casablanca in Morocco, Colon in Panama, Copenhagen in Denmark, Dakar in Senegal, Gdansk in Poland, Hamburg in Germany, Helsinki in Finland, Las Palmas in Canary Islands, Spain, Le Havre in France, Lisbon in Portugal, London in UK, Marseille in France, Montevideo in Uruguay, Montreal in Canada, Naples in Italy, New Orleans in US, New York in US, Oran in Algeria, Oslo in Norway, Peiraiefs or Piraeus in Greece, Rio de Janeiro in Brazil, Rotterdam in Netherlands, Saint Petersburg in Russia, Stockholm in Sweden
The natural hazards in the atlantic ocean include icebergs in Davis Strait, Denmark Strait, and the northwestern Atlantic Ocean and have been spotted as far south as Bermuda and the Madeira Islands. Persistent fog and hurricanes can also be hazards
Kiel Canal and Saint Lawrence Seaway are two important waterways. Atlantic waters have high risk for piracy and armed robbery against ships, particularly in the Gulf of Guinea off West Africa, the east coast of Brazil, and the Caribbean Sea. Numerous commercial vessels have been attacked and hijacked both at anchor and while underway. hijacked vessels are often disguised and cargoes stolen. Crews have been robbed and stores or cargoes stolen
The lowest point in the atlantic ocean is the Milwaukee Deep in the Puerto Rico Trench which is 8,605 m deep
Puerto rico trench
Interesting facts about the Atlantic Ocean
- Of all the world's oceans, Atlantic Ocean is the youngest
- Atlantic Ocean receives water from about half the world's land area. Numerous rivers flow into the ocean.
- Atlantic Ocean was the first ocean to be crossed by ship and airplane.
- In South Atlantic, there is a wide stretch of ocean between the tips of South Africa and South America, which causes huge waves & continuous strong winds, known as the "Roaring Forties".
- The warm Gulf Stream of Atlantic Ocean keeps harbors in the Northern Europe away from ice, during winters.
- Sonar waves are used by scientists to map the floor of Atlantic Ocean.
- Puerto Rico Trench is the deepest point in Atlantic Ocean. It is about eight and a half thousand meters deep.
- The largest island in Atlantic Ocean is Greenland.
- The Cancun reef of Atlantic Ocean, is the world's second largest barrier reef, after the Great Barrier Reef of Australia.
- In World War II, the Queen Mary and Queen Elizabeth carried US troops across the Atlantic, to Europe.
- In the winter storms of the Atlantic waves can reach a great size and do untold damage to land.
- Atlantic Ocean causes the highest tides in the world, which occur in the Bay of Fundy, Canada, with a rise of around fifty feet in the spring tides.
- Atlantic Ridge, the underwater mountain range which runs 10,000 miles south from Iceland, is twice as wide as the AndesMountains.
- Diamonds are scooped from the sea bed off the coast of Namibia, in southern Africa.
- A triangular area in Atlantic Ocean, called The Bermuda Triangle, is held responsible for mysterious shipwrecks, disappearances and air crashes.
- Titanic, the largest ship in the world sank in Atlantic Ocean in 1912, after being hit by an iceberg on her maiden voyage to America.
- In 1938, a coelacanth, a type of fish that first appeared in the sea some 300 million years ago, was caught alive by the fishermen off the Southern coast of Africa. These fishes were thought to be extinct for more than 60 million years.
The Indian Ocean
The Indian Ocean is the third largest ocean in the world. It has an area of 68.556 million sq km, which includes AndamanSea, Arabian Sea, Bay of Bengal, FloresSea, Great Australian Bight, Gulf of Aden, Gulf of Oman, Java Sea, Mozambique Channel, Persian Gulf, Red Sea, SavuSea, Strait of Malacca, Timor Sea, and other tributary water bodies
The Indian Ocean’s endangered marine species include the dugong, seals, turtles, and whales. There is great oil pollution in the Arabian Sea, Persian Gulf, and Red Sea. The natural resources of the Indian Ocean are oil and gas fields, fish, shrimp, sand and gravel aggregates, placer deposits and polymetallic nodules.
There are a few ports and terminals in the Indian ocean, namly Chennai in India, Colombo in Sri Lanka, Durban in South Africa, Jakarta in Indonesia, Kolkata in India, Melbourne in Australia, Mumbai in India and RichardsBay in South Africa.
The natural hazards in the Indian Ocean are the occasional icebergs which pose navigational hazard.
The Indian Ocean provides major sea routes connecting the Middle East, Africa, and East Asia with Europe and the Americas. It carries a particularly heavy traffic of petroleum and petroleum products from the oilfields of the Persian Gulf and Indonesia. Its fish are of great and growing importance to the bordering countries for domestic consumption and export. Fishing fleets from Russia, Japan, South Korea, and Taiwan also exploit the Indian Ocean, mainly for shrimp and tuna. An estimated 40% of the world's offshore oil production comes from the Indian Ocean. Beach sands rich in heavy minerals and offshore placer deposits are actively exploited by bordering countries, particularly India, South Africa, Indonesia, Sri Lanka, and Thailand.
The territorial waters of littoral states and offshore waters have high risk for piracy and armed robbery against ships, particularly in the Gulf of Aden, along the east coast of Africa, the Bay of Bengal, and the Strait of Malacca. Numerous vessels, including commercial shipping and pleasure craft, have been attacked and hijacked both at anchor and while underway. Hijacked vessels are often disguised and cargoes stolen and crew and passengers are often held for ransom, murdered, or cast adrift
The lowest point in the Indian Ocean is the Java Trench which is 7,258 m deep.
Interesting facts about indian ocean
- The Indian Ocean is the warmest ocean in the world.
- Approximately 40% of the world's offshore oil production comes from the Indian Ocean.
- Fishing in IndiaOcean is restricted to subsistence level.
- The Indian Ocean is known as 'Ratnakara' in the ancient Sanskrit literature. Ratnakara means 'the maker (creator) of jewels'.
- The lowest point in Indian Ocean is Java Trench with a depth of 7, 258 m.
- The Island nations housed by the Indian Ocean are Madagascar (formerly Malagasy Republic), the world's fourth largest island; Comoros, Seychelles, Maldives, Mauritius and Sri Lanka.
- The Ocean was dominated by the United Kingdom in early 1800s, and after the decline of the British Empire, it was dominated by India and Australia.
The Southern Ocean
The Southern Ocean is formed by combining the southern portions of the Atlantic Ocean, Indian Ocean, and Pacific Ocean and is the fourth largest ocean of the world. The ocean is very deep, averaging between 4,000 and 5,000 meters. There are huge icebergs that serve as a natural hazard. Ultraviolet radiation has caused a reduction in marine life.
The area of southern ocean is 20.327 million sq km which includes Amundsen Sea, Bellingshausen Sea, part of the Drake Passage, RossSea, a small part of the ScotiaSea, Weddell Sea, and other tributary water bodies.
The natural resources available in this ocean are large and possible giant oil and gas fields on the continental margin, manganese nodules, possible placer deposits, sand and gravel, fresh water as icebergs, squid, whales, and seals - none exploited, krill, fish
Increased solar ultraviolet radiation is reducing marine productivity by as much as 15% and damaging the DNA of some fish. There is also large amount of incidental mortality of seabirds resulting from long-line fishing for toothfish. The now-protected fur seal population is making a strong comeback after severe overexploitation in the 18th and 19th centuries
The ports and terminals in southern ocean include McMurdo, Palmer, and offshore anchorages in Antarctica. A few ports or harbors exist on southern side of Southern Ocean. Ice conditions limit use of most ports to short periods in midsummer
The Southern Ocean is deep, 4,000 to 5,000 m over most of its extent with only limited areas of shallow water. The Antarctic continental shelf is generally narrow and unusually deep. The Antarctic icepack grows from an average minimum of 2.6 million sq km in March to about 18.8 million sq km in September
The lowest point in the southern ocean is at the southern end of the South Sandwich Trench which is 7,235 m deep.
Southern Sandwich Island
Huge icebergs with drafts up to several hundred meters form in this sea, also are available smaller bergs and iceberg fragments. Deep continental shelf is floored by glacial deposits varying widely over short distances. High winds and large waves can be seen much of the year.
Fisheries play an important role in this oceans economy, which include varieties of fish like krill, Patagonian toothfish. The drake Passage offers alternative to transit through the Panama Canal.
Interesting facts about the southern ocean
- Krill is the cornerstone of the Antarctic’s ecology. Seals, whales, penguins and many other seabirds depend on it for their basic food.
- The Wandering albatross, with a 3.5metre wingspan, is the largest seabird in the world. Satellite tracking has shown that the Wandering albatross can reach an amazing 88 km per hour and keep flying for days at a time at an average speed of over 30km per hour.
- Crabeater seals number 14-30 million, making them the commonest large mammals on Earth after humans.
- The total world population of Chinstrap penguins is estimated to be about 6.5 million and all but about 10,000 nest on the Antarctic Peninsula or the islands nearby.
- Many Antarctic invertebrates living in the Southern Ocean are scavengers, feeding on anything that has died and sunk to the seabed, such as a penguin carcass. They also feed on anything discarded and seal faeces are an important source of food!
- The total number of Emperor penguins is unknown because new colonies are still being discovered, but there may be 135,000 – 175,000 pairs breeding in approximately 40 sites around the Antarctic continent.
- Apart from seals, the baleen and toothed whales are the only mammals indigenous to the Antarctic. The majority of the toothed whales are far smaller than most of the baleen whales and so few of the toothed whales were ever hunted.
- The massive reduction in the stock of whales as a result of commercial whaling activities is the single largest human impact to the Southern Ocean ecosystem.
The Arctic Ocean
The Arctic Ocean is the smallest of the world's five oceansThe Northwest Passage and Northern Sea Route are two important seasonal waterways. The area of the arctic ocean is 14.056 million sq km, which includes Baffin Bay, Barents Sea, Beaufort Sea, ChukchiSea, East Siberian Sea, Greenland Sea, Hudson Bay, HudsonStrait, KaraSea, Laptev Sea, Northwest Passage, and other tributary water bodies
The natural resources of this ocean include sand and gravel aggregates, placer deposits, polymetallic nodules, oil and gas fields, fish, marine mammals. The endangered marine species include walruses and whales. The ecosystem is fragile and is slow to change and slow to recover from disruptions or damage. The thinning polar icepack is another threat to this ocean.
The ports and terminalsin this ocean are Churchill in Canada, Murmansk in Russia, Prudhoe Bay in US.
The polar climate is characterized by persistent cold and relatively narrow annual temperature ranges, winters are characterized by continuous darkness, cold and stable weather conditions, and clear skies, while summers are characterized by continuous daylight, damp and foggy weather, and weak cyclones with rain or snow.
The polar icepack is about 3 meters thick. The lowest point in the southern ocean is the FramBasin which is 4,665 m deep.
Economic activity is limited to the exploitation of natural resources, including petroleum, natural gas, fish, and seals.
Interesting facts about the Arctic ocean
- The Arctic Ocean is the smallest of the five oceans of the world. It's roughly 8% the size of the Pacific Ocean.
- The Arctic Ocean has a coastline of 45,389 km and has depth of 4,665 m (from basin).
- The economic activity from the ocean is limited to the utilization of natural resources, including petroleum, natural gas, fish, and seals.
- The Arctic Ocean's cold sheet of floating ice is resting place to seals, polar bears and arctic fox.
- The floating ice is around 16 million sq. km, which shrinks to 9 million sq. km. in summers.
- The Arctic Ocean's ice sheet is four times as large as the state of Texas.
- More fish live along the edges of the Arctic Ocean than anywhere else on the Earth.
- Its average winter temperature is minus 30 degrees Fahrenheit. However, during summers, the temperature can rise up to plus 50 degrees Fahrenheit.
- The Arctic is the only place on the Earth where polar bears live. It receives roughly 8 inches of rain every year.