The oceans are said to be the "source of life." The enormous, blue, calm oceans are the signatures of the planet earth. They cover nearly three-fourths of the surface of the earth. This is equal to 71 percent of the earth's entire surface or about 361 million sq km (140 million sq mi). Its average depth is 5000 m (16,000 ft), and its total volume is about 1,347,000,000 cu km (322,300,000 cu mi). This includes the Atlantic, Pacific, and Indian oceans. These oceans are bordered by the continental masses or by ocean ridges or currents. The ocean basins hold at immense amount of over 285 million cubic miles of water (1185 million cu. km.). This quantity of water developed from the Earth's interior as it cooled.
In order to understand the role water plays in our lives, you must know the chemistry of water itself. Each molecule of water is composed of two hydrogen atoms and one oxygen atom. The hydrogen atoms bond to the oxygen atom unevenly by sharing electrons. This is shown in figure 1-1. Important interactions take place because of the electron sharing. The oxygen atom tends to draw the electrons provided by the Hydrogen atoms closer to its nucleus, making an electrical separation and a polar molecule. The polar nature results in the hydrogen end (which has a positive charge) attracting the oxygen end (with a negative charge) of other nearby water molecules. This forms hydrogen bonds between other water molecules. These bonds are weak compared to the electron sharing bonds (6% as strong) and are easily broken and changed.
There are many different properties of the ocean water. Seawater is fresh water and dissolved solids in gases due to erosion and weathering of landmasses. In figure 1-3, it shows the electromagnetic spectrum and the transmission of light into fresh or salt water. Objects such as rocks are being dissolved by rainwater and flowing out to sea with the rivers. The gases come from... the atmosphere. As water is a universal solvent, many different compounds are dissolved in it. A 1kg sample of saltwater contains 35g of dissolved compounds, including inorganic salts, organic compounds from living organisms, and dissolved gasses. The amount of salt in more than 95 percent of the worlds oceans normally averages about from 33 to 37 parts per thousand, with and average of 35 parts per thousand. The northern subtropical portions of the Atlantic Ocean are very salty. They are at least 37.5 parts per thousand. The Pacific Ocean is less salty (34 ppt), and the arctic and Antarctic oceans art the least salty. The water is usually less salty where large amounts of freshwater are supplied by melting ice, rivers, or rainfall. The saltiest water is found in waters where there is a minimum of rainfall or river runoff, and a lot of evaporation. For example, the Persian Gulf and the red sea ...
Pacific Ocean
The Pacific Ocean is the largest of the world's five oceansArea:
total: 155.557 million sq kmnote: 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
Natural resources:
oil and gas fields, polymetallic nodules, sand and gravel aggregates, placer deposits, fishEnvironment - current issues:
endangered marine species include the dugong, sea lion, sea otter, seals, turtles, and whales; oil pollution in Philippine Sea and South China Sea
Ports and terminals:
Bangkok (Thailand), Hong Kong (China), Kao-hsiung (Taiwan), Los Angeles (US), Manila (Philippines), Pusan (South Korea), San Francisco (US), Seattle (US), Shanghai (China), Singapore, Sydney (Australia), Vladivostok (Russia), Wellington (NZ), Yokohama (Japan)Environment - current issues:
Pacific Ocean endangered marine species include the dugong, sea lion, sea otter, seals, turtles, and whales; oil pollution in Philippine Sea and South China SeaThe Pacific Ocean is a major contributor to the world economy and particularly to those nations its waters directly touch. It provides low-cost sea transportation between East and West, extensive fishing grounds, offshore oil and gas fields, minerals, and sand and gravel for the construction industry. In 1996, over 60% of the world's fish catch came from the Pacific Ocean. Exploitation of offshore oil and gas reserves is playing an ever-increasing role in the energy supplies of the US, Australia, NZ, China, and Peru. The high cost of recovering offshore oil and gas, combined with the wide swings in world prices for oil since 1985, has led to fluctuations in new drillings.
Geography - note:
The Pacific Ocean has major chokepoints 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; dotted with low coral islands and rugged volcanic islands in the southwestern Pacific OceanThe Pacific Ocean is the largest of the world's five oceans (followed by the Atlantic Ocean, Indian Ocean, Southern Ocean, and Arctic Ocean). Strategically important access waterways include the La Perouse, Tsugaru, Tsushima, Taiwan, Singapore, and Torres Straits. The decision by the International Hydrographic Organization in the spring of 2000 to delimit a fifth ocean, the Southern Ocean, removed the portion of the Pacific Ocean south of 60 degrees south.
Mariana Trench, depression in the floor of the Pacific Ocean, the deepest seafloor depression in the world. It is located just east of the Mariana Islands in the western part of the ocean basin. The Mariana Trench is an arc-shaped valley extending generally northeast to southwest for 2,550 km (1,580 mi); its average width is 70 km (40 mi). The Mariana is one of many deepwater ocean trenches formed by the geologic process of subduction
Natural resources:
The Pacific Ocean has oil and gas fields, polymetallic nodules, sand and gravel aggregates, placer deposits, fishNatural hazards:
The Pacific Ocean is surrounded by a zone of violent volcanic and earthquake activity sometimes referred to as the "Pacific Ring of Fire"; 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); cyclical El Nino/La Nina phenomenon occurs in the equatorial Pacific, influencing weather in the Western Hemisphere and the western Pacific; ships subject to superstructure icing in extreme north from October to May; persistent fog in the northern Pacific can be a maritime hazard from June to December..Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceansArea:
total: 76.762 million sq kmnote: 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 Scotia Sea, and other tributary water bodies
Natural resources:
oil and gas fields, fish, marine mammals (seals and whales), sand and gravel aggregates, placer deposits, polymetallic nodules, precious stonesEnvironment - current issues:
endangered marine species include the manatee, seals, sea lions, turtles, and whales; drift net fishing is hastening the decline of fish stocks and contributing to international disputes; municipal sludge pollution off eastern US, southern Brazil, and eastern Argentina; oil pollution in Caribbean Sea, Gulf of Mexico, Lake Maracaibo, Mediterranean Sea, and North Sea; industrial waste and municipal sewage pollution in Baltic Sea, North Sea, and Mediterranean SeaPorts and terminals:
Alexandria (Egypt), Algiers (Algeria), Antwerp (Belgium), Barcelona (Spain), Buenos Aires (Argentina), Casablanca (Morocco), Colon (Panama), Copenhagen (Denmark), Dakar (Senegal), Gdansk (Poland), Hamburg (Germany), Helsinki (Finland), Las Palmas (Canary Islands, Spain), Le Havre (France), Lisbon (Portugal), London (UK), Marseille (France), Montevideo (Uruguay), Montreal (Canada), Naples (Italy), New Orleans (US), New York (US), Oran (Algeria), Oslo (Norway), Peiraiefs or Piraeus (Greece), Rio de Janeiro (Brazil), Rotterdam (Netherlands), Saint Petersburg (Russia), Stockholm (Sweden)Natural hazards:
icebergs common in Davis Strait, Denmark Strait, and the northwestern Atlantic Ocean from February to August and have been spotted as far south as Bermuda and the Madeira Islands; ships subject to superstructure icing in extreme northern Atlantic from October to May; persistent fog can be a maritime hazard from May to September; hurricanes (May to December)Geography - note:
major chokepoints include the Dardanelles, Strait of Gibraltar, access to the Panama and Suez Canals; strategic straits include the Strait of Dover, Straits of Florida, Mona Passage, The Sound (Oresund), and Windward Passage; the Equator divides the Atlantic Ocean into the North Atlantic Ocean and South Atlantic OceanEconomy - overview:
The Atlantic Ocean provides some of the world's most heavily trafficked sea routes, between and within the Eastern and Western Hemispheres. Other economic activity includes the exploitation of natural resources, e.g., fishing, dredging of aragonite sands (The Bahamas), and production of crude oil and natural gas (Caribbean Sea, Gulf of Mexico, and North Sea).South Atlantic Flash
The Vela Incident (sometimes referred to as the South Atlantic Flash) was an unidentified "double flash" of light that was detected by an American Vela Hotel satellite on September 22, 1979.Some specialists who examined the data speculated that the double flash, characteristic of a nuclear explosion, may have been the result of a nuclear weapons test: "The conclusions of the Presidential panel (the Ad Hoc Panel) were reassuring, as they suggested that the most likely explanation of the Vela detection was a meteoroid hitting the satellite — in part because of the discrepancy in bhangmeter readings. Others who examined the data, including Defense Intelligence Agency (DIA), the national laboratories, and defense contractors reached a very different conclusion — that the data supported the conclusion that on 22 September 1979, Vela 6911 had detected a nuclear detonation.
Indian Ocean
The Indian Ocean is the third largest of the world's five oceansArea:
total: 68.556 million sq kmnote: includes Andaman Sea, Arabian Sea, Bay of Bengal, Flores Sea, Great Australian Bight, Gulf of Aden, Gulf of Oman, Java Sea, Mozambique Channel, Persian Gulf, Red Sea, Savu Sea, Strait of Malacca, Timor Sea, and other tributary water bodies
Environment - current issues:
The Indian Ocean endangered marine species include the dugong, seals, turtles, and whales; oil pollution in the Arabian Sea, Persian Gulf, and Red SeaNatural resources:
The Indian Ocean oil and gas fields, fish, shrimp, sand and gravel aggregates, placer deposits, polymetallic nodulesPorts and terminals:
Chennai (Madras; India), Colombo (Sri Lanka), Durban (South Africa), Jakarta (Indonesia), Kolkata (Calcutta; India) Melbourne (Australia), Mumbai (Bombay; India), Richards Bay (South Africa)Natural hazards:
The Indian Ocean occasional icebergs pose navigational hazard in southern reachesEnvironment - current issues:
The Indian Ocean endangered marine species include the dugong, seals, turtles, and whales; oil pollution in the Arabian Sea, Persian Gulf, and Red SeaGeography - note:
Major chokepoints in Indian Ocean include Bab el Mandeb, Strait of Hormuz, Strait of Malacca, southern access to the Suez Canal, and the Lombok StraitEconomy - overview:
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. Large reserves of hydrocarbons are being tapped in the offshore areas of Saudi Arabia, Iran, India, and western Australia. 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 Indian Ocean is the third largest of the world's five oceans (after the Pacific Ocean and Atlantic Ocean, but larger than the Southern Ocean and Arctic Ocean). Four critically important access waterways are the Suez Canal (Egypt), Bab el Mandeb (Djibouti-Yemen), Strait of Hormuz (Iran-Oman), and Strait of Malacca (Indonesia-Malaysia). The decision by the International Hydrographic Organization in the spring of 2000 to delimit a fifth ocean, the Southern Ocean, removed the portion of the Indian Ocean south of 60 degrees south latitude.
The Indian Ocean northeast monsoon (December to April), southwest monsoon (June to October); tropical cyclones occur during May/June and October/November in the northern Indian Ocean and January/February in the southern Indian Ocean
The Indian Ocean surface dominated by counterclockwise gyre (broad, circular system of currents) in the southern Indian Ocean; unique reversal of surface currents in the northern Indian Ocean; low atmospheric pressure over southwest Asia from hot, rising, summer air results in the southwest monsoon and southwest-to-northeast winds and currents, while high pressure over northern Asia from cold, falling, winter air results in the northeast monsoon and northeast-to-southwest winds and currents; ocean floor is dominated by the Mid-Indian Ocean Ridge and subdivided by the Southeast Indian Ocean Ridge, Southwest Indian Ocean Ridge, and Ninetyeast Ridge
The Indian Ocean lowest point: Java Trench -7,258 m
Transportation - note:
The International Maritime Bureau reports the territorial waters of littoral states and offshore waters as 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; crew and passengers are often held for ransom, murdered, or cast adrift.Southern OceanThe Southern Ocean as the fourth-largest of the five oceansThe Southern Ocean, also known as the Great Southern Ocean, the Antarctic Ocean and the South Polar Ocean Area:total: 20.327 million sq kmnote: includes Amundsen Sea, Bellingshausen Sea, part of the Drake Passage, Ross Sea, a small part of the Scotia Sea, Weddell Sea, and other tributary water bodies Natural resources:probable 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, fishEnvironment - current issues:increased solar ultraviolet radiation resulting from the Antarctic ozone hole in recent years, reducing marine primary productivity (phytoplankton) by as much as 15% and damaging the DNA of some fish; illegal, unreported, and unregulated fishing in recent years, especially the landing of an estimated five to six times more Patagonian toothfish than the regulated fishery, which is likely to affect the sustainability of the stock; large amount of incidental mortality of seabirds resulting from long-line fishing for toothfishnote: the now-protected fur seal population is making a strong comeback after severe overexploitation in the 18th and 19th centuries Ports and terminals:McMurdo, Palmer, and offshore anchorages in AntarcticaNote: few ports or harbors exist on southern side of Southern Ocean; ice conditions limit use of most to short periods in midsummer; even then some cannot be entered without icebreaker escort; most Antarctic ports are operated by government research stations and, except in an emergency, are not open to commercial or private vessels; vessels in any port south of 60 degrees south are subject to inspection by observers under Article 7 of the Antarctic Treaty; The Hydrographic Committee on Antarctica (HCA), a special hydrographic commission of International Hydrographic Organization (IHO), is responsible for hydrographic surveying and nautical charting matters in Antarctic Treaty area; it coordinates and facilitates provision of accurate and appropriate charts and other aids to navigation in support of safety of navigation in region; membership of HCA is open to any IHO Member State whose government has acceded to the Antarctic Treaty and which contributes resources and/or data to IHO Chart coverage of the area; members of HCA are Argentina, Australia, Brazil, Chile, China, Ecuador, France, Germany, Greece, India, Italy, NZ, Norway, Russia, South Africa, Spain, UK, and US (2007) Terrain: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, its edge lying at depths of 400 to 800 m (the global mean is 133 m); 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, better than a sixfold increase in area; the Antarctic Circumpolar Current (21,000 km in length) moves perpetually eastward; it is the world's largest ocean current, transporting 130 million cubic meters of water per second - 100 times the flow of all the world's riverslowest point: -7,235 m at the southern end of the South Sandwich Trench Natural hazards:huge icebergs with drafts up to several hundred meters; smaller bergs and iceberg fragments; sea ice (generally 0.5 to 1 m thick) with sometimes dynamic short-term variations and with large annual and interannual variations; deep continental shelf floored by glacial deposits varying widely over short distances; high winds and large waves much of the year; ship icing, especially May-October; most of region is remote from sources of search and rescueGeography - note:the major chokepoint is the Drake Passage between South America and Antarctica; the Polar Front (Antarctic Convergence) is the best natural definition of the northern extent of the Southern Ocean; it is a distinct region at the middle of the Antarctic Circumpolar Current that separates the cold polar surface waters to the south from the warmer waters to the north; the Front and the Current extend entirely around Antarctica, reaching south of 60 degrees south near New Zealand and near 48 degrees south in the far South Atlantic coinciding with the path of the maximum westerly windsDisputes - international:Antarctic Treaty defers claims, but Argentina, Australia, Chile, France, NZ, Norway, and UK assert claims (some overlapping), including the continental shelf in the Southern Ocean; several states have expressed an interest in extending those continental shelf claims under the United Nations Convention on the Law of the Sea (UNCLOS) to include undersea ridges; the US and most other states do not recognize the land or maritime claims of other states and have made no claims themselves (the US and Russia have reserved the right to do so); no formal claims exist in the waters in the sector between 90 degrees west and 150 degrees west
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