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Oceans
Pacific Ocean Background: The 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. The Pacific Ocean was named by legendary navigator Ferdinand Magellan. A native of Portugal, Magellan renounced his loyalty to that nation after King Emanuel rejected Magellan’s petition for a post within the royal navy. Magellan then left for Spain, which agreed to support Magellan’s claim of a western route to the Spice Islands through a seaway near the southern tip of South America. On September 20, 1519, Magellan and a crew of 270 men set sail from Spain on their around-the-world voyage in five small vessels including his flagship Trinidad, Concepcion, San Antonio, Victoria, and Santiago. It took the fleet, or at least the three remaining ships in the fleet, 38 days to navigate the strait around South America that was to bear Magellan’s name. During the last week of November, the fleet emerged into what Magellan described as a “beautiful, peaceful ocean.” Thus, it was named the Pacific Ocean (“pacific” meaning “peaceful.”) Upon entering the Pacific Ocean, Magellan mistakenly thought the Spice Islands were only a short voyage away. Nearly four months later, in March 1521, he and his crew finally reached what is known today as the Philippines. A few weeks later, he was fatally wounded after becoming involved in a dispute between warring Philippine tribes. Only one ship, Victoria, and 18 of Magellan’s original crew members returned to Spain, thereby completing the first circumnavigation of the globe. Although Magellan’s route proved impractical for the spice trade, his voyage has been called the greatest single human achievement on the seas. Geography: Location: Body of water between the Southern Ocean, Asia, Australia, and the Western Hemisphere. Area: Total: 155.557 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. Area - comparative: About 15 times the size of the US; covers about 28% of the global surface; larger than the total land area of the world. Coastline: 135,663 km Climate: Planetary air pressure systems and resultant wind patterns exhibit remarkable uniformity in the south and east; trade winds and westerly winds are well-developed patterns, modified by seasonal fluctuations; tropical cyclones (hurricanes) may form south of Mexico from June to October and affect Mexico and Central America; continental influences cause climatic uniformity to be much less pronounced in the eastern and western regions at the same latitude in the North Pacific Ocean; 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 landmass back to the ocean; tropical cyclones (typhoons) may strike southeast and east Asia from May to December. Depth: Its average depth is 4,637 meters (2.8 miles). It is home to the deepest known point in the ocean — the Mariana Trench off Guam — which plunges to a depth of about 10,924 meters (nearly 7 miles). Because of the depth of the Pacific Ocean, tsunamis (huge waves created by earthquakes) can reach speeds of 750 kilometers an hour, the same velocity as a jet airplane. Natural resources: One of the Pacific Ocean’s greatest assets is fish, including herring, salmon, sardines, snapper, swordfish, tuna, and shellfish. Pearls are harvested along Australia, Japan, Papua New Guinea, Nicaragua, Panama, and the Philippines. Natural hazards: In terms of natural hazards, the Pacific Ocean is surrounded by a zone of violent volcanic and earthquake activity (“The Ring of Fire”). Hurricanes may form south of Mexico and strike Central America and Mexico from June to October. The greatest typhoon frequency exists within the triangle from southern Japan to the central Philippines to eastern Micronesia. Environment - current issues: The Pacific Ocean’s endangered marine species include the dugong, sea lion, sea otter, seals, turtles, and whales. Current major environmental issues include oil pollution in the Philippine Sea and South China Sea. Geography - 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, dotted with low coral islands and rugged volcanic islands in the southwestern Pacific Ocean. Economy Economy - overview: The 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 half (60%) of the world’s total 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. Transportation 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). |
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Southern Ocean Back ground A large body of recent oceanographic research has shown that the Antarctic Circumpolar Current (ACC), an ocean current that flows from west to east around Antarctica, plays a crucial role in global ocean circulation. The region where the cold waters of the ACC meet and mingle with the warmer waters of the north defines a distinct border - the Antarctic Convergence - which fluctuates with the seasons, but which encompasses a discrete body of water and a unique ecologic region. The Convergence concentrates nutrients, which promotes marine plant life, and which in turn allows for a greater abundance of animal life. In the spring of 2000, the International Hydrographic Organization decided to delimit the waters within the Convergence as a fifth world ocean - the Southern Ocean - by combining the southern portions of the Atlantic Ocean, Indian Ocean, and Pacific Ocean. The Southern Ocean extends from the coast of Antarctica north to 60 degrees south latitude, which coincides with the Antarctic Treaty Limit and which approximates the extent of the Antarctic Convergence. As such, the Southern Ocean is now the fourth largest of the world's five oceans (after the Pacific Ocean, Atlantic Ocean, and Indian Ocean, but larger than the Arctic Ocean). It should be noted that inclusion of the Southern Ocean does not imply recognition of this feature as one of the world's primary oceans by the US Government. Location Body of water between 60 degrees south latitude and Antarctica Geographic co-ordinates 60 00 S, 90 00 E (nominally), but the Southern Ocean has the unique distinction of being a large circumpolar body of water totally encircling the continent of Antarctica; this ring of water lies between 60 degrees south latitude and the coast of Antarctica and encompasses 360 degrees of longitude Map references Antarctic Region Area Total: 20.327 million sq km ; note: 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 Area comparative Slightly more than twice the size of the US Coastline 17,968 km Climate Sea temperatures vary from about 10 degrees Celsius to -2 degrees Celsius; cyclonic storms travel eastward around the continent and frequently are intense because of the temperature contrast between ice and open ocean; the ocean area from about latitude 40 south to the Antarctic Circle has the strongest average winds found anywhere on Earth; in winter the ocean freezes outward to 65 degrees south latitude in the Pacific sector and 55 degrees south latitude in the Atlantic sector, lowering surface temperatures well below 0 degrees Celsius; at some coastal points intense persistent drainage winds from the interior keep the shoreline ice-free throughout the winter Terrain The Southern Ocean is deep, 4,000 to 5,000 meters 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 meters (the global mean is 133 meters); the Antarctic icepack grows from an average minimum of 2.6 million square kilometers in March to about 18.8 million square kilometers 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 rivers Elevation extremes Lowest point: -7,235 m at the southern end of the South Sandwich Trench ; highest point: sea level 0 m 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, fishes Natural hazards Huge icebergs with drafts up to several hundred meters; smaller bergs and iceberg fragments; sea ice (generally 0.5 to 1 meter 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 rescue Geography – 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 very 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 winds Ports and Terminals McMurdo, Palmer, and offshore anchorages in Antarctica ; note: 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 Antarctic Treaty observers (see Article 7); 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, Chile, China, France, Germany, Greece, India, Italy, NZ, Norway, Russia, South Africa, Spain, and the UK (2005) Transportation –note Drake Passage offers alternative to transit through the Panama Canal Atlantic Ocean Background The Atlantic Ocean is the second largest of the world's five oceans (after the Pacific Ocean, but larger than the Indian Ocean, Southern Ocean, and Arctic Ocean). The Kiel Canal (Germany), Oresund (Denmark-Sweden), Bosporus (Turkey), Strait of Gibraltar (Morocco-Spain), and the Saint Lawrence Seaway (Canada-US) are important strategic access waterways. The decision by the International Hydrographic Organization in the spring of 2000 to delimit a fifth world ocean, the Southern Ocean, removed the portion of the Atlantic Ocean south of 60 degrees south latitude. Location Body of water between Africa, Europe, the Southern Ocean, and the Western Hemisphere Geographic co-ordinates 0 00 N, 25 00 W Map references Political Map of the World Area Total: 76.762 million sq km ; note: 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 Area comparative Slightly less than 6.5 times the size of the US Coastline 111,866 km Climate Tropical cyclones (hurricanes) develop off the coast of Africa near Cape Verde and move westward into the Caribbean Sea; hurricanes can occur from May to December, but are most frequent from August to November Terrain surface usually covered with sea ice in Labrador Sea, Denmark Strait, and coastal portions of the Baltic Sea from October to June; clockwise warm-water gyre (broad, circular system of currents) in the northern Atlantic, counterclockwise warm-water gyre in the southern Atlantic; the ocean floor is dominated by the Mid-Atlantic Ridge, a rugged north-south centerline for the entire Atlantic basin Natural resources Oil and gas fields, fish, marine mammals (seals and whales), sand and gravel aggregates, placer deposits, polymetallic nodules, precious stones 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) Elevation extreme Lowest point: Milwaukee Deep in the Puerto Rico Trench -8,605 m ; highest point: sea level 0 m Ports 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) Transportation –note Kiel Canal and Saint Lawrence Seaway are two important waterways; significant domestic commercial and recreational use of Intracoastal Waterway on central and south Atlantic seaboard and Gulf of Mexico coast of US Indian Ocean Back ground 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. Location Body of water between Africa, the Southern Ocean, Asia, and Australia Geographic co-ordinates 20 00 S, 80 00 E Map references Political Map of the World Area Total: 68.556 million sq km ; note: 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 Area comparative About 5.5 times the size of the US Coast line 66,526 km Climate 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 Terrain 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 Natural resources Oil and gas fields, fish, shrimp, sand and gravel aggregates, placer deposits, polymetallic nodules Natural hazards Occasional icebergs pose navigational hazard in southern reaches Elevation extreme Lowest point: Java Trench -7,258 m ; highest point: sea level 0 m Geography –note Major chokepoints include Bab el Mandeb, Strait of Hormuz, Strait of Malacca, southern access to the Suez Canal, and the Lombok Strait Ports 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) Arctic Ocean Back ground The Arctic Ocean is the smallest of the world's five oceans (after the Pacific Ocean, Atlantic Ocean, Indian Ocean, and the recently delimited Southern Ocean). The Northwest Passage (US and Canada) and Northern Sea Route (Norway and Russia) are two important seasonal waterways. A sparse network of air, ocean, river, and land routes circumscribes the Arctic Ocean. Location Body of water between Europe, Asia, and North America, mostly north of the Arctic Circle Geographic co-ordinates 90 00 N, 0 00 E Map references Arctic Region Area Total: 14.056 million sq km ; note: includes Baffin Bay, Barents Sea, Beaufort Sea, Chukchi Sea, East Siberian Sea, Greenland Sea, Hudson Bay, Hudson Strait, Kara Sea, Laptev Sea, Northwest Passage, and other tributary water bodies Area comparative Slightly less than 1.5 times the size of the US Coastline 45,389 km Climate Polar climate characterized by persistent cold and relatively narrow annual temperature ranges; winters characterized by continuous darkness, cold and stable weather conditions, and clear skies; summers characterized by continuous daylight, damp and foggy weather, and weak cyclones with rain or snow Terrain Central surface covered by a perennial drifting polar icepack that, on average, is about 3 meters thick, although pressure ridges may be three times that thickness; clockwise drift pattern in the Beaufort Gyral Stream, but nearly straight-line movement from the New Siberian Islands (Russia) to Denmark Strait (between Greenland and Iceland); the icepack is surrounded by open seas during the summer, but more than doubles in size during the winter and extends to the encircling landmasses; the ocean floor is about 50% continental shelf (highest percentage of any ocean) with the remainder a central basin interrupted by three submarine ridges (Alpha Cordillera, Nansen Cordillera, and Lomonosov Ridge) Elevation extreme Lowest point: Fram Basin -4,665 m ; highest point: sea level 0 m Natural resources Sand and gravel aggregates, placer deposits, polymetallic nodules, oil and gas fields, fish, marine mammals (seals and whales) Natural hazards Ice islands occasionally break away from northern Ellesmere Island; icebergs calved from glaciers in western Greenland and extreme northeastern Canada; permafrost in islands; virtually ice locked from October to June; ships subject to superstructure icing from October to May Geography – note Major chokepoint is the southern Chukchi Sea (northern access to the Pacific Ocean via the Bering Strait); strategic location between North America and Russia; shortest marine link between the extremes of eastern and western Russia; floating research stations operated by the US and Russia; maximum snow cover in March or April about 20 to 50 centimeters over the frozen ocean; snow cover lasts about 10 months Ports and Terminals Churchill (Canada) Murmansk (Russia) Prudhoe Bay (US) Transportation –note Sparse network of air, ocean, river, and land routes; the Northwest Passage (North America) and Northern Sea Route (Eurasia) are important seasonal waterways
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