The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about 106,400,000 square kilometres (41,100,000 sq mi), it covers approximately twenty percent of the Earth's surface and about twenty-six percent of its water surface area. The first part of its name refers to Atlas of Greek mythology, making the Atlantic the "Sea of Atlas".
The oldest known mention of "Atlantic" is in The Histories of Herodotus around 450 BC (Hdt. 1.202.4): Atlantis thalassa (Greek: Ἀτλαντὶς θάλασσα; English: Sea of Atlas); see also: Atlas Mountains. The term Ethiopic Ocean, derived from Ethiopia, was applied to the southern Atlantic ocean as late as the mid-19th century.[1] Before Europeans discovered other oceans, the term "ocean" itself was synonymous with the waters beyond the Strait of Gibraltar that we now know as the Atlantic. The early Greeks believed this ocean to be a gigantic river encircling the world.
The Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between the Americas to the west, and Eurasia and Africa to the east. As one component of the interconnected global ocean, it is connected in the north to the Arctic Ocean (which is sometimes considered a sea of the Atlantic), to the Pacific Ocean in the southwest, the Indian Ocean in the southeast, and the Southern Ocean in the south. (Other definitions describe the Atlantic as extending southward to Antarctica.) The equator subdivides it into the North Atlantic Ocean and South Atlantic Ocean.
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The Atlantic Ocean is bounded on the west by North and South America. It connects to the Arctic Ocean through the Denmark Strait, Greenland Sea, Norwegian Sea and Barents Sea. To the east, the boundaries of the ocean proper are Europe; the Strait of Gibraltar (where it connects with the Mediterranean Sea –one of its marginal seas– and, in turn, the Black Sea) and Africa.
In the southeast, the Atlantic merges into the Indian Ocean. The 20° East meridian, running south from Cape Agulhas to Antarctica defines its border. Some authorities show it extending south to Antarctica, while others show it bounded at the 60° parallel by the Southern Ocean.[2]
In the southwest, the Drake Passage connects it to the Pacific Ocean. The man-made Panama Canal links the Atlantic and Pacific. Besides those mentioned, other large bodies of water adjacent to the Atlantic are the Caribbean Sea; the Gulf of Mexico; Hudson Bay; the Arctic Ocean; the Mediterranean Sea; the North Sea; the Baltic Sea and the Celtic Sea.
Covering approximately 22% of Earth's surface, the Atlantic is second in size to the Pacific. With its adjacent seas, it occupies an area of about 106,400,000 square kilometres (41,100,000 sq mi); without them, it has an area of 82,400,000 square kilometres (31,800,000 sq mi). The land that drains into the Atlantic covers four times that of either the Pacific or Indian oceans. The volume of the Atlantic with its adjacent seas is 354,700,000 cubic kilometers (85,100,000 cu mi) and without them 323,600,000 cubic kilometres (77,640,000 cu mi).
The average depth of the Atlantic, with its adjacent seas, is 3,339 metres (10,955 ft); without them it is 3,926 metres (12,881 ft). The greatest depth, Milwaukee Deep with 8,605 metres (28,232 ft), is in the Puerto Rico Trench. The Atlantic's width varies from 2,848 kilometres (1,770 mi) between Brazil and Sierra Leone to over 6,400 km (4,000 mi) in the south.[citation needed]
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Transatlantic travel played a major role in the expansion of Western civilization into the Americas. It is the Atlantic that separates the "Old World" from the "New World". In modern times, some idioms refer to the ocean in a humorously diminutive way as the Pond, describing both the geographical and cultural divide between North America and Europe, in particular between the English-speaking nations of both continents. Many British people refer to the USA and Canada as "across the pond", and vice versa.[3]
The principal feature of the bathymetry (bottom topography) is a submarine mountain range called the Mid-Atlantic Ridge.[4] It extends from Iceland in the north to approximately 58° South latitude, reaching a maximum width of about 1,600 kilometres (990 mi). A great rift valley also extends along the ridge over most of its length. The depth of water at the apex of the ridge is less than 2,700 metres (8,900 ft) in most places, the bottom of the ridge is three times as deep and of course several peaks rise above the water and form islands.[5] The South Atlantic Ocean has an additional submarine ridge, the Walvis Ridge.[6]
The Mid-Atlantic Ridge separates the Atlantic Ocean into two large troughs with depths from 3,700–5,500 metres (12,100–18,000 ft). Transverse ridges running between the continents and the Mid-Atlantic Ridge divide the ocean floor into numerous basins. Some of the larger basins are the Blake, Guiana, North American, Cape Verde, and Canaries basins in the North Atlantic. The largest South Atlantic basins are the Angola, Cape, Argentina, and Brazil basins.
The deep ocean floor is thought to be fairly flat with occasional deeps, abyssal plains, trenches, seamounts, basins, plateaus, canyons, and some guyots. Various shelves along the margins of the continents constitute about 11% of the bottom topography with few deep channels cut across the continental rise.
Ocean floor trenches and seamounts:
Ocean sediments are composed of:
On average, the Atlantic is the saltiest major ocean; surface water salinity in the open ocean ranges from 33 to 37 parts per thousand (3.3 - 3.7%) by mass and varies with latitude and season. Evaporation, precipitation, river inflow and sea ice melting influence surface salinity values. Although the salinity values are just north of the equator (because of heavy tropical rainfall), in general the lowest values are in the high latitudes and along coasts where large rivers enter. Maximum salinity values occur at about 25° north and south, in subtropical regions with low rainfall and high evaporation.
Surface water temperatures, which vary with latitude, current systems, and season and reflect the latitudinal distribution of solar energy, range from below −2 °C (28 °F). Maximum temperatures occur north of the equator, and minimum values are found in the polar regions. In the middle latitudes, the area of maximum temperature variations, values may vary by 7-8 °C (12-15 °F).
The Atlantic Ocean consists of four major water masses. The North and South Atlantic central waters make up the surface. The sub-Antarctic intermediate water extends to depths of 1,000 metres (3,300 ft). The North Atlantic Deep Water reaches depths of as much as 4,000 metres (13,000 ft). The Antarctic Bottom Water occupies ocean basins at depths greater than 4,000 meters.
Within the North Atlantic, ocean currents isolate the Sargasso Sea, a large elongated body of water, with above average salinity. The Sargasso Sea contains large amounts of seaweed and is also the spawning ground for both the European eel and the American eel.
The Coriolis effect circulates North Atlantic water in a clockwise direction, whereas South Atlantic water circulates counter-clockwise. The south tides in the Atlantic Ocean are semi-diurnal; that is, two high tides occur during each 24 lunar hours. In latitudes above 40° North some east-west oscillation occurs.
Climate is influenced by the temperatures of the surface waters and water currents as well as winds. Because of the ocean's great heat retention capacity, maritime climates are more moderate and have less extreme seasonal variations than inland climates. Precipitation can be approximated from coastal weather data and air temperature from water temperatures.
The oceans are the major source of the atmospheric moisture that is obtained through evaporation. Climatic zones vary with latitude; the warmest zones stretch across the Atlantic north of the equator. The coldest zones are in high latitudes, with the coldest regions corresponding to the areas covered by sea ice. Ocean currents influence climate by transporting warm and cold waters to other regions. The winds that are cooled or warmed when blowing over these currents influence adjacent land areas.
The Gulf Stream and its northern extension towards Europe, the North Atlantic Drift, for example, warms the atmosphere of the British Isles and north-western Europe, and the cold water currents contribute to heavy fog off the coast of eastern Canada (the Grand Banks of Newfoundland area) and Africa's north-western coast. In general, winds transport moisture and air over land areas. Hurricanes develop in the southern part of the North Atlantic Ocean.
The Atlantic Ocean appears to be the second youngest of the five oceans. It did not exist prior to 130 million years ago, when the continents that formed from the breakup of the ancestral super continent Pangaea were drifting apart from seafloor spreading. The Atlantic has been extensively explored since the earliest settlements along its shores.
The Vikings, the Portuguese, and the Spaniards were the most famous among early explorers. After Columbus, European exploration rapidly accelerated, and many new trade routes were established.
As a result, the Atlantic became and remains the major artery between Europe and the Americas (known as transatlantic trade). Scientific explorations include the Challenger expedition, the German Meteor expedition, Columbia University's Lamont-Doherty Earth Observatory and the United States Navy Hydrographic Office.
The Aethiopian Sea, Ethiopic Ocean or Ethiopian Ocean (Okeanos Aithiopos), is an old name for what is now called the South Atlantic Ocean, which is separated from the North Atlantic Ocean by a narrow region between Natal, Brazil and Monrovia, Liberia. The use of this term illustrates a past trend towards referring to the whole continent of Africa by the name Aethiopia. The modern nation of Ethiopia, in northeast Africa, is nowhere near the Ethiopic Ocean, which would be said to lie off the west coast of Africa. The term Ethiopian Ocean sometimes appeared until the mid-19th century.[citation needed]
The Atlantic has contributed significantly to the development and economy of surrounding countries. Besides major transatlantic transportation and communication routes, the Atlantic offers abundant petroleum deposits in the sedimentary rocks of the continental shelves. The Atlantic hosts the world's richest fishing resources, especially in the waters covering the shelves. The major fish are cod, haddock, hake, herring, and mackerel.
The most productive areas include Newfoundland's Grand Banks, the Nova Scotia shelf, Georges Bank off Cape Cod, the Bahama Banks, the waters around Iceland, the Irish Sea, the Dogger Bank of the North Sea, and the Falkland Banks. Eel, lobster, and whales appear in great quantities. Various international treaties attempt to reduce pollution caused by environmental threats such as oil spills, marine debris, and the incineration of toxic wastes at sea.
From October to June the surface is usually covered with sea ice in the Labrador Sea, Denmark Strait, and Baltic Sea. A clockwise warm-water gyre occupies the northern Atlantic, and a counter-clockwise warm-water gyre appears in the southern Atlantic. The Mid-Atlantic Ridge, a rugged north-south centerline for the entire Atlantic basin, first discovered by the Challenger Expedition dominates the ocean floor. This was formed by the vulcanism that also formed the ocean floor and the islands rising from it.
The Atlantic has irregular coasts indented by numerous bays, gulfs, and seas. These include the Norwegian Sea, Baltic Sea, North Sea, Labrador Sea, Black Sea, Gulf of Saint Lawrence, Bay of Fundy, Gulf of Maine, Mediterranean Sea, Gulf of Mexico, and Caribbean Sea.
Islands include Greenland, Iceland, Faroe Islands, Great Britain (including numerous surrounding islands), Ireland, Rockall, Newfoundland, Sable Island, Azores, Madeira, Bermuda, Canary Islands, Caribbean, Cape Verde, São Tomé and Príncipe, Annobón Province, Fernando de Noronha, Rocas Atoll, Ascension Island, Saint Helena, The Islands of Trindad, Tristan da Cunha, Gough Island (Also known as Diego Alvarez), Falkland Islands, Tierra del Fuego, South Georgia Island, South Sandwich Islands, and Bouvet Island.
The Atlantic harbors petroleum and gas fields, fish, marine mammals (seals and whales), sand and gravel aggregates, placer deposits, polymetallic nodules, and precious stones.
Icebergs are common from February to August in the Davis Strait, Denmark Strait, and the northwestern Atlantic and have been spotted as far south as Bermuda and Madeira. Ships are subject to superstructure icing in the extreme north from October to May. Persistent fog can be a maritime hazard from May to September, as can hurricanes north of the equator (May to December).
The United States' southeast coast has a long history of shipwrecks due to its many shoals and reefs. The Virginia and North Carolina coasts were particularly dangerous.
The Bermuda Triangle is popularly believed to be the site of numerous aviation and shipping incidents because of unexplained and supposedly mysterious causes, but Coast Guard records do not support this belief.
Hurricanes are also a natural hazard in the Atlantic, but mainly in the northern part of the ocean, rarely tropical cyclones form in the southern parts. Hurricanes usually form between June 1 and November 30 of every year. The most notable hurricane in the Atlantic would be Hurricane Katrina in the 2005 season.
Endangered marine species include the manatee, seals, sea lions, turtles, and whales. Drift net fishing can kill dolphins, albatrosses and other seabirds (petrels, auks), hastening the fish stock decline and contributing to international disputes.[13] Municipal pollution comes from the eastern United States, southern Brazil, and eastern Argentina; oil pollution in the Caribbean Sea, Gulf of Mexico, Lake Maracaibo, Mediterranean Sea, and North Sea; and industrial waste and municipal sewage pollution in the Baltic Sea, North Sea, and Mediterranean Sea.
In 2005, there was some concern that warm northern European currents were slowing down, but no scientific consensus formed from that evidence.[14]
On June 7, 2006, Florida's wildlife commission voted to take the manatee off the state's endangered species list. Some environmentalists worry that this could erode safeguards for the popular sea creature.
Marine pollution is a generic term for the entry into the ocean of potentially hazardous chemicals or particles. The biggest culprits are rivers and with them many agriculture fertilizer chemicals as well as livestock and human waste. The excess of oxygen-depleting chemicals leads to hypoxia and the creation of a dead zone.[15]
Marine debris, which is also known as marine litter, describes human-created waste floating in a body of water. Oceanic debris tends to accumulate at the center of gyres and coastlines, frequently washing aground where it is known as beach litter.
The states (territories in italics) with a coastline on the Atlantic Ocean (excluding the Baltic and Mediterranean Seas) are:
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List of U.S. states by date of statehood Admitted on December 10, 1817 (20th) |
Succeeded by Illinois |
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The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, bounded by Asia and Australia in the west, and the Americas in the east.
At 165.2 million square kilometres (63.8 million square miles) in area, this largest division of the World Ocean – and, in turn, the hydrosphere – covers about 46% of the Earth's water surface and about one-third of its total surface area, making it larger than all of the Earth's land area combined.[1] The equator subdivides it into the North Pacific Ocean and South Pacific Ocean, with two exceptions: the Galápagos and Gilbert Islands, while straddling the equator, are deemed wholly within the South Pacific.[2] The Mariana Trench in the western North Pacific is the deepest point in the world, reaching a depth of 10,911 metres (35,797 ft).[3]
The Pacific Ocean was sighted by Europeans early in the 16th century, first by the Spanish explorer Vasco Núñez de Balboa, who crossed the Isthmus of Panama in 1513 and named it Mar del Sur (South Sea). Its current name was given by Portuguese explorer Ferdinand Magellan during the Spanish expedition of world circumnavigation in 1521, who encountered favourable winds as he reached the ocean and called it Mar Pacifico in Portuguese, meaning "peaceful sea".[4]
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The Pacific Ocean encompasses approximately one-third of the Earth's surface, having an area of 165.2 million square kilometres (63.8 million square miles) —significantly larger than Earth's entire landmass, with room for another Africa to spare.
Extending approximately 15,500 kilometres (9,600 mi) from the Bering Sea in the Arctic to the northern extent of the circumpolar Southern Ocean at 60°S (older definitions extend it to Antarctica's Ross Sea), the Pacific reaches its greatest east-west width at about 5°N latitude, where it stretches approximately 19,800 kilometres (12,300 mi) from Indonesia to the coast of Colombia and Peru – halfway across the world, and more than five times the diameter of the Moon. The lowest known point on earth—the Mariana Trench—lies 10,911 metres (35,797 ft) below sea level. Its average depth is 4028~4188metres (14,000 ft).[1]
The Pacific Ocean is currently shrinking due to plate tectonics, while the Atlantic Ocean is increasing in size, by roughly an inch per year (2–3 cm/yr) on 3 sides, roughly averaging 0.2 square miles (0.5 km2) a year.
Along the Pacific Ocean's irregular western margins lie many seas, the largest of which are the Celebes Sea, Coral Sea, East China Sea, Philippine Sea, Sea of Japan, South China Sea, Sulu Sea, Tasman Sea, and Yellow Sea. The Strait of Malacca joins the Pacific and the Indian Oceans on the west, and Drake Passage and the Straits of Magellan link the Pacific with the Atlantic Ocean on the east. To the north, the Bering Strait connects the Pacific with the Arctic Ocean.
As the Pacific straddles the 180th meridian, the West Pacific (or western Pacific, near Asia) is in the Eastern Hemisphere, while the East Pacific (or eastern Pacific, near the Americas) is in the Western Hemisphere.
For most of Magellan's voyage from the Strait of Magellan to the Philippines, the explorer indeed found the ocean peaceful. However, the Pacific is not always peaceful. Many tropical storms batter the islands of the Pacific. The lands around the Pacific Rim are full of volcanoes and often affected by earthquakes. Tsunamis, caused by underwater earthquakes, have devastated many islands and in some cases destroyed entire towns.
The volume of the Pacific Ocean is approximately 622 million cubic km. Water temperatures in the Pacific vary from freezing in the poleward areas to about 30 °C (86 °F) near the equator. Salinity also varies latitudinally. The water near the equator is less salty than that found in the mid-latitudes because of abundant equatorial precipitation throughout the year. Poleward of the temperate latitudes salinity is also low, because little evaporation of seawater takes place in these frigid areas.
The motion of Pacific waters is generally clockwise in the Northern Hemisphere (the North Pacific gyre) and counter-clockwise in the Southern Hemisphere. The North Equatorial Current, driven westward along latitude 15°N by the trade winds, turns north near the Philippines to become the warm Japan or Kuroshio Current.
Turning eastward at about 45°N, the Kuroshio forks and some waters move northward as the Aleutian Current, while the rest turn southward to rejoin the North Equatorial Current. The Aleutian Current branches as it approaches North America and forms the base of a counter-clockwise circulation in the Bering Sea. Its southern arm becomes the chilled slow, south-flowing California Current.
The South Equatorial Current, flowing west along the equator, swings southward east of New Guinea, turns east at about 50°S, and joins the main westerly circulation of the Southern Pacific, which includes the Earth-circling Antarctic Circumpolar Current. As it approaches the Chilean coast, the South Equatorial Current divides; one branch flows around Cape Horn and the other turns north to form the Peru or Humboldt Current.
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The andesite line is the most significant regional distinction in the Pacific. It separates the deeper, mafic igneous rock of the Central Pacific Basin from the partially submerged continental areas of felsic igneous rock on its margins. The andesite line follows the western edge of the islands off California and passes south of the Aleutian arc, along the eastern edge of the Kamchatka Peninsula, the Kuril Islands, Japan, the Mariana Islands, the Solomon Islands, and New Zealand's North Island.
The dissimilarity continues northeastward along the western edge of the Andes Cordillera along South America to Mexico, returning then to the islands off California. Indonesia, the Philippines, Japan, New Guinea, and New Zealand lie outside the Andesite Line.
The Pacific Ocean takes up roughly one third of the Earth's surface, having an area of 179.7 million square kilometers. It contains about 25,000 islands (more than the total number in the rest of the world's oceans combined), the majority of which are found south of the equator, Including partially submerged islands. The ocean was mapped by a man named Abraham Ortelius; he called it Maris Pacifici because of Ferdinand Magellan, who sailed the Pacific during his circumnavigation from 1519 to 1522 and said that it was much more calm than the Atlantic.
The Pacific Ocean has several long seamount chains (which are chains of mountains submerging from the ocean seafloor) formed by hotspot volcanism. "The Ring of Fire" is the world's largest belt of explosive volcanism. It is named after the several hundred active volcanoes that sit above the various subduction zones (which are geological processes in which one edge of a crustal plate is forced sideways and downward into the mantle below another plate).
Within the closed loop of the Andesite Line are most of the deep troughs, submerged volcanic mountains, and oceanic volcanic islands that characterize the Pacific basin. Here basaltic lavas gently flow out of rifts to build huge dome-shaped volcanic mountains whose eroded summits form island arcs, chains, and clusters. Outside the Andesite Line, volcanism is of the explosive type, and the Pacific Ring of Fire is the world's foremost belt of explosive volcanism. The Ring of Fire is named after the several hundred active volcanoes that sit above the various subduction zones.
The Pacific Ocean is the only ocean which is almost totally bounded by subduction zones. Only the Antarctic and Australian coasts have no nearby subduction zones.
The Pacific Ocean developed from the Panthalassic Ocean following the breakup of Pangaea. There is no firm date for when the changeover occurred, as the replacement of the sea bed is a continuous process, though reconstruction maps often change the name from Panthalassic to Pacific around the time the Atlantic Ocean began to open.[5][6][7] The Panthalassic Ocean first opened 750 million years ago at the breakup of Rodinia,[7] but the oldest Pacific Ocean floor is only around 180 Ma old.[8]
The Pacific Ocean contains several long seamount chains, formed by hotspot volcanism. These include the Hawaiian – Emperor seamount chain and the Louisville seamount chain.
The largest landmass entirely within the Pacific Ocean is the island of New Guinea— the second largest island in the world. Almost all of the smaller islands of the Pacific lie between 30°N and 30°S, extending from Southeast Asia to Easter Island; the rest of the Pacific Basin is almost entirely submerged. During the Last glacial period, New Guinea was part of Australia so the largest landmass would have been Borneo–Palawan.
The great triangle of Polynesia, connecting Hawaii, Easter Island, and New Zealand, encompasses the island arcs and clusters of the Cook Islands, Marquesas Islands, Samoa, Society, Tokelau, Tonga, Tuamotu, Tuvalu and the Wallis and Futuna islands.
North of the equator and west of the International Date Line are the numerous small islands of Micronesia, including the Caroline Islands, the Marshall Islands and the Mariana Islands.
In the southwestern corner of the Pacific lie the islands of Melanesia, dominated by New Guinea. Other important island groups of Melanesia include the Bismarck Archipelago, Fiji, New Caledonia, the Solomon Islands and Vanuatu.
Islands in the Pacific Ocean are of four basic types: continental islands, high islands, coral reefs, and uplifted coral platforms. Continental islands lie outside the Andesite line and include New Guinea, the islands of New Zealand, and the Philippines. Some of these islands are structurally associated with nearby continents. High islands are of volcanic origin, and many contain active volcanoes. Among these are Bougainville, Hawaii, and the Solomon Islands.
The third and fourth types of islands are both the result of coralline island building. Coral reefs are low-lying structures that have built up on basaltic lava flows under the ocean's surface. One of the most dramatic is the Great Barrier Reef off northeastern Australia. A second island type formed of coral is the uplifted coral platform, which is usually slightly larger than the low coral islands. Examples include Banaba (formerly Ocean Island) and Makatea in the Tuamotu group of French Polynesia.
Important human migrations occurred in the Pacific in prehistoric times, most notably those of the Polynesians from the Asian edge of the ocean to Tahiti and then to Hawaii, New Zealand, and Easter Island.
The ocean was sighted by Europeans early in the 16th century, first by the Spanish explorer Vasco Núñez de Balboa who crossed the Isthmus of Panama in 1513 and named it as Mar del Sur (South Sea), and then by the Portuguese explorer Ferdinand Magellan, who sailed the Pacific on a Spanish expedition of world circumnavigation from 1519 to 1521. Magellan called the ocean Pacífico or "Pacific" because he encountered calm seas throughout his journey. Although Magellan himself died in the Philippines in 1521, Spanish navigator Juan Sebastian Elcano led the expedition back to Spain across the Indian Ocean and round the Cape of Good Hope, completing the first world circumnavigation in 1522.
In 1564, Spanish explorers crossed the ocean from Mexico led by Miguel López de Legazpi who sailed to the Philippines and Mariana Islands. For the remainder of the 16th century, Spanish influence was paramount, with ships sailing from Mexico and Peru across the Pacific Ocean to the Philippines, via Guam, and establishing the Spanish East Indies. The Manila Galleons operated for two and a half centuries linking Manila and Acapulco, in one of the longest trade routes in history. Spanish expeditions also discovered Tuvalu, the Marquesas, the Solomon Islands and New Guinea in the South Pacific.
In the quest for Terra Australis, Spanish explorers in the 17th century discovered the Pitcairn and Vanuatu archipelagos in the South Pacific. Dutch explorers, sailing around southern Africa, also engaged in discovery and trade; Abel Janszoon Tasman discovered Tasmania and New Zealand in 1642. The 18th century marked the beginning of major exploration by the Russians in Alaska and the Aleutian Islands. The Spanish also sent expeditions to the Pacific Northwest reaching Vancouver Island in southern Canada, and Alaska. The French explored and settled Polynesia, and the British made three voyages with James Cook to the South Pacific and Australia, Hawaii, and the North American Pacific Northwest.
Growing imperialism during the 19th century resulted in the occupation of much of Oceania by European powers, and later, the United States and Japan. Significant contributions to oceanographic knowledge were made by the voyages of HMS Beagle in the 1830s, with Charles Darwin aboard; HMS Challenger during the 1870s; the USS Tuscarora (1873–76); and the German Gazelle (1874–76).
Although the United States gained control of Guam and the Philippines from Spain in 1898, Japan controlled most of the western Pacific by 1914 and occupied many other islands during World War II. However, by the end of that war, Japan was defeated and the U.S. Pacific Fleet was the virtual master of the ocean. Since the end of World War II, many former colonies in the Pacific have become independent states.
The exploitation of the Pacific's mineral wealth is hampered by the ocean's great depths. In shallow waters of the continental shelves off the coasts of Australia and New Zealand, petroleum and natural gas are extracted, and pearls are harvested along the coasts of Australia, Japan, Papua New Guinea, Nicaragua, Panama, and the Philippines, although in sharply declining volume in some cases.
The Pacific's greatest asset is its fish. The shoreline waters of the continents and the more temperate islands yield herring, salmon, sardines, snapper, swordfish, and tuna, as well as shellfish.
Marine pollution is a generic term for the harmful entry into the ocean of chemicals or particles. The biggest culprits are people who use the rivers for disposing of their waste.[10] The rivers then empty into the Ocean, and with it the many chemicals used as fertilizers in agriculture. The excess of oxygen depleting chemicals in the water leads to hypoxia and the creation of a dead zone.[11]
Marine debris, also known as marine litter, is a term used to describe human-created waste that has found itself floating in a lake, sea, ocean or waterway. Oceanic debris tends to accumulate at the centre of gyres and coastlines, frequently washing aground where it is known as beach litter.[10]
1 Note that Taiwan's status as a sovereign nation is disputed.
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Oregon (
i/ˈɔrɨɡən/ or-ə-gən)[6] is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern boundaries, respectively. The area was inhabited by many indigenous tribes before the arrival of traders, explorers, and settlers who formed an autonomous government in Oregon Country in 1843. The Oregon Territory was created in 1848, and Oregon became the 33rd state on February 14, 1859.
Salem is the state's capital and third-most-populous city; Portland is the most populous. Oregon's 2010 population is just over 3.8 million, a 12% increase over 2000.[7] Portland is the 29th-largest U.S. city, with a population of 583,776 (2010 US Census) and a metro population of 2,241,841 (2009 estimate), the 23rd-largest U.S. metro area. The valley of the Willamette River in western Oregon is the state's most densely populated area and is home to eight of the ten most populous cities.
Oregon contains a diverse landscape including the windswept Pacific coastline, the volcanoes of the rugged and glaciated Cascade Mountain Range, many waterfalls (including Multnomah Falls), dense evergreen forests, and high desert across much of the eastern portion of the state, extending into the Great Basin. The tall Douglas firs and redwoods along the rainy Western Oregon coast contrast with the lower density and fire prone pine tree and juniper forests covering portions of the eastern half of the state. Stretching east from Central Oregon, the state also includes semi-arid shrublands, prairies, deserts, steppes, and meadows. Mount Hood is the highest point in the state at 11,249 feet (3,429 m). Crater Lake National Park is the only national park in Oregon.
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List of U.S. states by date of statehood Admitted on November 11, 1889 (42nd) |
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Washington
i/ˈwɒʃɪŋtən/ is a state in the Pacific Northwest region of the United States located south of British Columbia, north of Oregon, and west of Idaho, on the coast of the Pacific Ocean. Washington was carved out of the western part of Washington Territory which had been ceded by Britain in 1846 by the Oregon Treaty as settlement of the Oregon Boundary Dispute. It was admitted to the Union as the 42nd state in 1889.
The 2010 United States Census recorded the state's population at 6,724,540. Approximately 60 percent of Washington's residents live in the Seattle metropolitan area, the center of transportation, business, and industry along the Puget Sound region of the Salish Sea, an inlet of the Pacific consisting of numerous islands, deep fjords, and bays carved out by glaciers. The remainder of the state consists of deep rain forests in the west, mountain ranges in the west, center, northeast and far southeast, and a semi-arid eastern basin given over to intensive agriculture. Washington is second most populous state on the west coast and in the western United States after California.
Washington was named after George Washington, the first President of the United States, and is the only U.S. state named after a president. Washington is commonly called Washington state or occasionally the State of Washington to distinguish it from the U.S. capital. However, Washingtonians (residents of Washington) and many residents of neighboring states and Canadians from southern B.C. normally refer to the state simply as "Washington", while usually referring to the nation's capital as "Washington, D.C." or simply "D.C." Ironically the area was originally called "Columbia" after the Columbia River. However, it was thought this would cause confusion with the District of Columbia, so the area was renamed Washington.
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Washington is the northwesternmost state of the contiguous United States. Its northern border lies mostly along the 49th parallel, and then via marine boundaries through the Strait of Georgia, Haro Strait and Strait of Juan de Fuca, with the Canadian province of British Columbia to the north. Washington borders Oregon to the south, with the Columbia River forming most of the boundary and the 46th parallel forming the eastern part of the southern boundary.
To the east, Washington borders Idaho, bounded mostly by the meridian running north from the confluence of the Snake River and Clearwater River (about 116°57' west), except for the southernmost section where the border follows the Snake River. To the west of Washington lies the Pacific Ocean.[3] Washington was a Union territory during the American Civil War, although it never actually participated in the war.
Washington is part of a region known as the Pacific Northwest, a term which always includes Washington and Oregon and may or may not include Idaho, western Montana, northern California, and part or all of British Columbia, Alaska, and the Yukon Territory, depending on the user's intent.
The high mountains of the Cascade Range run north-south, bisecting the state. Western Washington, from the Cascades westward, has a mostly marine west coast climate with mild temperatures and wet winters, autumns, and springs, and relatively dry summers. Western Washington also supports dense forests of conifers and areas of temperate rain forest.[4]
In contrast, Eastern Washington, east of the Cascades, has a relatively dry climate with large areas of semiarid steppe and a few truly arid deserts lying in the rainshadow of the Cascades; the Hanford reservation receives an average annual precipitation of between six and seven inches (178 mm). Farther east, the climate becomes less arid. The Palouse southeast region of Washington was grassland that has been mostly converted into farmland. Other parts of eastern Washington are forested and mountainous.
The Cascade Range contains several volcanoes, which reach altitudes significantly higher than the rest of the mountains. From the north to the south these volcanoes are Mount Baker, Glacier Peak, Mount St. Helens, and Mount Adams. Mount St. Helens is currently the only Washington volcano that is actively erupting; however, all of them are considered active volcanoes. The state is also home to Mt. Rainier, a volcano 50 miles (80 km) south of the city of Seattle, from which it is prominently visible. The 14,411-foot (4,392 m)-tall Mt. Rainier is considered the most dangerous volcano in the continental U.S.,[5] due to its proximity to the Seattle metropolitan area. It is also listed as a Decade Volcano.
Washington's position on the Pacific Ocean and the harbors of Puget Sound give the state a leading role in maritime trade with Alaska, Canada, and the Pacific Rim. Puget Sound's many islands are served by the largest ferry fleet in the United States.
Washington is a land of contrasts. The deep forests of the Olympic Peninsula, such as the Hoh Rain Forest, are among the only temperate rainforests in the continental United States, but the semi-desert east of the Cascade Range has few trees. Mount Rainier, the highest mountain in the state,[2] is covered with more glacial ice than any other peak in the lower 48 states.[6]
Olympic National Park is designated as a UNESCO World Heritage Site as well as International Biosphere Reserve.
The following United States federal areas are in Washington.
There are three National Parks and two National Monuments in Washington:
Nine national forests are located (at least partly) in Washington:
31 wildernesses are located (at least partly) in Washington, including:
23 National Wildlife Refuges are located (at least partly) in Washington including:
Other protected lands of note include:
There are several large military-related reservations, including:
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