East Siberian Sea
The East Siberian Sea is a marginal sea in the Arctic Ocean. It is located between the Arctic Cape to the north, the coast of Siberia to the south, the New Siberian Islands to the west and Cape Billings, close to Chukotka and this sea borders on the Laptev Sea to the west and the Chukchi Sea to the east. This sea is one of the least studied in the Arctic area, the sea shores were inhabited for thousands of years by indigenous tribes of Yukaghirs and Evens and Evenks, which were engaged in fishing and reindeer husbandry. They were absorbed by Yakuts and by Russians, major industrial activities in the area are mining and navigation within the Northern Sea Route, commercial fishing is poorly developed. The largest city and port is Pevek, the northernmost city of mainland Russia, the present name was assigned to the sea on 27 June 1935 by Decree of the Soviet Government. Before that, the sea had no name was intermixedly called in Russia as Indigirskoe, Severnoe, Sibirskoe or Ledovitoe. The International Hydrographic Organization defines the limits of the East Siberian Sea as follows, the Eastern limit of Laptev Sea.
A line from the Northernmost point of Wrangel Island to the Northern sides of the De Long Islands and Bennett Island, from the Northernmost point of Wrangel Island through this island to Cape Blossom thence to Cape Yakan on the main land. Because it is open towards the Arctic Ocean in the north, the gulfs of the East Siberian Sea, like the Kolyma Bay, the Kolyma Gulf. There are no islands in the middle of the East Siberian Sea, but there are a few islands and island groups in its waters, like Ayon Island. The total area of the islands is only 80 km2, some islands mostly consist of sand and ice and gradually erode. The total catchment area is 1,342,000 km2, among the rivers flowing into the East Siberian Sea, the Indigirka, Uyandina, Kolyma, Rauchua and Pegtymel are the most important. Only a few rivers are navigable, the coastline of the sea is 3,016 km long. It makes large bends, sometimes stretching deep into the land, fine bends are rare and occur only in the river deltas. The coastal section between the New Siberian Islands and the mouth of the Kolyma River is uniform, with low and it extends landwards to the marshy tundra filled with numerous small lakes.
In contrast, the coast to the east of the Kolyma River is mountainous, about 70% of the sea is shallower than 50 m, with predominant depths of 20–25 m. North-east to the mouth of the Kolyma and Indigirka rivers, there are deep trenches on the seabed, the region of small depths in the western part forms the Novosibirsk shoal. The greatest depths of about 150 m are found in the part of the sea
It contains the geographic South Pole and is situated in the Antarctic region of the Southern Hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean. At 14,000,000 square kilometres, it is the fifth-largest continent, for comparison, Antarctica is nearly twice the size of Australia. About 98% of Antarctica is covered by ice that averages 1.9 km in thickness, Antarctica, on average, is the coldest and windiest continent, and has the highest average elevation of all the continents. Antarctica is a desert, with precipitation of only 200 mm along the coast. The temperature in Antarctica has reached −89.2 °C, though the average for the quarter is −63 °C. Anywhere from 1,000 to 5,000 people reside throughout the year at the research stations scattered across the continent. Organisms native to Antarctica include many types of algae, fungi, protista, where it occurs, is tundra. The continent, remained neglected for the rest of the 19th century because of its hostile environment, lack of easily accessible resources.
In 1895, the first confirmed landing was conducted by a team of Norwegians, Antarctica is a de facto condominium, governed by parties to the Antarctic Treaty System that have consulting status. Twelve countries signed the Antarctic Treaty in 1959, and thirty-eight have signed it since then, the treaty prohibits military activities and mineral mining, prohibits nuclear explosions and nuclear waste disposal, supports scientific research, and protects the continents ecozone. Ongoing experiments are conducted by more than 4,000 scientists from many nations, the name Antarctica is the romanised version of the Greek compound word ἀνταρκτική, feminine of ἀνταρκτικός, meaning opposite to the Arctic, opposite to the north. Aristotle wrote in his book Meteorology about an Antarctic region in c.350 B. C, marinus of Tyre reportedly used the name in his unpreserved world map from the 2nd century A. D. Before acquiring its present geographical connotations, the term was used for locations that could be defined as opposite to the north.
For example, the short-lived French colony established in Brazil in the 16th century was called France Antarctique, the first formal use of the name Antarctica as a continental name in the 1890s is attributed to the Scottish cartographer John George Bartholomew. Antarctica has no population and there is no evidence that it was seen by humans until the 19th century. Explorer Matthew Flinders, in particular, has credited with popularising the transfer of the name Terra Australis to Australia. Cook came within about 120 km of the Antarctic coast before retreating in the face of ice in January 1773. The first confirmed sighting of Antarctica can be narrowed down to the crews of ships captained by three individuals, according to various organisations, ships captained by three men sighted Antarctica or its ice shelf in 1820, von Bellingshausen, Edward Bransfield, and Nathaniel Palmer
The Andes or Andean Mountains are the longest continental mountain range in the world. They are a range of highlands along the western edge of South America. This range is about 7,000 km long, about 200 to 700 km wide, the Andes extend from north to south through seven South American countries, Colombia, Peru, Bolivia and Chile. Along their length, the Andes are split into several ranges, the Andes are the location of several high plateaus – some of which host major cities, such as Quito, Bogotá, Medellín, Sucre, Mérida and La Paz. The Altiplano plateau is the worlds second-highest after the Tibetan plateau and these ranges are in turn grouped into three major divisions based on climate, the Tropical Andes, the Dry Andes, and the Wet Andes. The Andes are the worlds highest mountain range outside of Asia, the highest mountain outside Asia, Mount Aconcagua, rises to an elevation of about 6,961 m above sea level. The peak of Chimborazo in the Ecuadorean Andes is farther from the Earths center than any other location on the Earths surface, the worlds highest volcanoes are in the Andes, including Ojos del Salado on the Chile-Argentina border, which rises to 6,893 m.
The etymology of the word Andes has been debated, the majority consensus is that it derives from the Quechua word anti, which means east as in Antisuyu, one of the four regions of the Inca Empire. In the northern part of the Andes, the isolated Sierra Nevada de Santa Marta range is considered to be part of the Andes. The term cordillera comes from the Spanish word cordel, meaning rope, the Andes range is about 200 km wide throughout its length, except in the Bolivian flexure where it is about 640 kilometres wide. The Andes are the result of plate tectonics processes, caused by the subduction of oceanic crust beneath the South American plate. The main cause of the rise of the Andes is the compression of the rim of the South American Plate due to the subduction of the Nazca Plate. In the south, the Andes share a boundary with the former Patagonia Terrane. To the west, the Andes end at the Pacific Ocean, from a geographical approach, the Andes are considered to have their western boundaries marked by the appearance of coastal lowlands and a less rugged topography.
The Andes Mountains contain large quantities of iron ore located in mountains within the range. The Andean orogen has a series of bends or oroclines, the Bolivian Orocline is a seaward concave bending in the coast of South America and the Andes Mountains at about 18° S. At this point the orientation of the Andes turns from Northwest in Peru to South in Chile, the Andean segment north and south of the orocline have been rotated 15° to 20° counter clockwise and clockwise respectively. The Bolivian Orocline area overlaps with the area of maximum width of the Altiplano Plateau, the specific point at 18° S where the coastline bends is known as the Arica Elbow
The Archipelago Sea is a part of the Baltic Sea between the Gulf of Bothnia, the Gulf of Finland and the Sea of Åland, within Finnish territorial waters. By some definitions it contains the largest archipelago in the world by the number of islands, although many of the islands are very small, the larger islands are inhabited and connected by ferries and bridges. The Åland Islands, including the largest islands of the region, the rest of the islands are part of the Southwest Finland region. The Archipelago Sea is a significant tourist destination, the Archipelago Sea covers a roughly triangular area with the cities of Mariehamn and Hanko, at the corners. The archipelago can be divided into inner and outer archipelagos, with the outer archipelago consisting mainly of smaller, the total surface area is 8,300 square kilometres, of which 2,000 square kilometres is land. The archipelago has a large number of islands. The number of the islands of over 1 km2 within the Archipelago Sea is 257. If the number of smallest uninhabitable rocks and skerries is accounted,50,000 is probably a good estimate, in comparison, the number of islands in Canadian Arctic Archipelago is 36,563.
Indonesia has 17,508 islands, according to the Indonesian Naval Hydro-Oceanographic Office, the islands began emerging from the sea shortly after the last ice age. Due to the rebound the process is still going on, with new skerries and islands being slowly created. The current rate of rebound is between 4 and 10 millimetres a year, because the islands are made of mainly granite and gneiss, two very hard types of rock, erosion is significantly slower than rebound. However, due to its location, the effect of postglacial rebound is smaller than for example than in Kvarken further north. The sea area is shallow, with a depth of 23 m. Most of the channels are not navigable for large ships, there are three crater-like formations in the archipelago. One of them, Lumparn in Åland, is an impact crater. The two other formations are intrusions, the more prominent of these is the Åva Intrusion in the municipality of Brändö, which is easily notable in satellite photos and high-resolution maps. The other similar formation is in Fjälskär, between the islands of Houtskär and Iniö.
The islands are divided between the region of Southwest Finland and the region of Åland
The Beaufort Sea is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, the Yukon, and Alaska, west of Canadas Arctic islands. The sea is named after hydrographer Sir Francis Beaufort, the major Mackenzie River empties into the Canadian part of the sea, west of Tuktoyaktuk, which is one of the few permanent settlements on the sea shores. The sea, characterized by climate, is frozen over most of the year. Historically, only a narrow pass up to 100 km opened in August–September near its shores, claims that the seacoast was populated about 30,000 years ago have been largely discredited, present population density is very low. The sea contains significant resources of petroleum and natural gas under its shelf and they were discovered in the period between the 1950s and 1980s, and their exploration became the major human activity in the area since the 1980s. The traditional occupations of fishery and whale and seal hunting are practiced only locally, as a result, the sea hosts one of the largest colonies of beluga whales, and there is no sign of overfishing.
To prevent overfishing in its waters, the US adopted precautionary commercial fisheries management plan in August 2009, in April 2011 the Canadian government signed a memorandum of understanding with the Inuvialuit as a first step in developing a larger ocean management plan. The Canadian government has set a new block of the Beaufort Sea off the Parry Peninsula in the Amundsen as a Marine Protected Area, the protected area is set to protect species and habits for the Inuvialuit community. The International Hydrographic Organization defines the limits of the Beaufort Sea as follows, a line from Point Barrow, Alaska, to Lands End, Prince Patrick Island. There is a dispute involving a wedge-shaped slice on the International Boundary in the Beaufort Sea. Canada claims the maritime boundary to be along the 141st meridian west out to a distance of 200 nmi, following the Alaska–Yukon land border. The position of the United States is that the line is perpendicular to the coast out to a distance of 200 nmi.
This difference creates a wedge with an area of about 21,000 km2 that is claimed by both nations, Canadas position has its roots in the Treaty of Saint Petersburg between the United Kingdom and the Russian Empire that set the boundary between the two. They differ on what should be deemed equitable, Canada contends that an equidistance principle does not result in an equitable boundary, because distortion would occur. The coast of Yukon is concave, whereas the coast of Alaska is convex, because of this, Canada argues that special circumstances apply to this border, a position that the U. S. rejects. Before the end of 2004, the US leased eight plots of land below the water for oil exploration and exploitation, provoking a diplomatic protest from Canada. On 20 August 2009, United States Secretary of Commerce Gary Locke announced a moratorium on fishing of the Beaufort Sea north of Alaska. In July 2010, US–Canada negotiations have started in Ottawa with the meeting planned in 2011
The continental shelf is an underwater landmass which extends from a continent, resulting in an area of relatively shallow water known as a shelf sea. Much of the shelves were exposed during glacial periods and interglacial periods, the shelf surrounding an island is known as an insular shelf. The continental margin, between the shelf and the abyssal plain, comprises a steep continental slope followed by the flatter continental rise. Sediment from the continent above cascades down the slope and accumulates as a pile of sediment at the base of the slope, extending as far as 500 km from the slope, it consists of thick sediments deposited by turbidity currents from the shelf and slope. The continental rises gradient is intermediate between the slope and the shelf, on the order of 0. 5–1°, the largest shelf – the Siberian Shelf in the Arctic Ocean – stretches to 1,500 kilometers in width. The South China Sea lies over another extensive area of shelf, the Sunda Shelf, which joins Borneo, Sumatra.
Other familiar bodies of water that overlie continental shelves are the North Sea, the average width of continental shelves is about 80 km. The depth of the shelf varies, but is limited to water shallower than 150 m. The slope of the shelf is quite low, on the order of 0. 5°, vertical relief is minimal. Though the continental shelf is treated as a province of the ocean, it is not part of the deep ocean basin proper. Passive continental margins such as most of the Atlantic coasts have wide and shallow shelves, active continental margins have narrow, relatively steep shelves, due to frequent earthquakes that move sediment to the deep sea. The shelf usually ends at a point of increasing slope, the sea floor below the break is the continental slope. Below the slope is the rise, which finally merges into the deep ocean floor. The continental shelf and the slope are part of the continental margin, the shelf area is commonly subdivided into the inner continental shelf, mid continental shelf, and outer continental shelf, each with their specific geomorphology and marine biology.
The character of the shelf changes dramatically at the shelf break, with a few exceptions, the shelf break is located at a remarkably uniform depth of roughly 140 m, this is likely a hallmark of past ice ages, when sea level was lower than it is now. The continental slope is steeper than the shelf, the average angle is 3°. The slope is cut with submarine canyons. The physical mechanisms involved in forming these canyons were not well understood until the 1960s, the continental shelves are covered by terrigenous sediments, that is, those derived from erosion of the continents
The Barents Sea is a marginal sea of the Arctic Ocean, located off the northern coasts of Norway and Russia divided between Norwegian and Russian territorial waters. Known among Russians in the Middle Ages as the Murman Sea and it is a rather shallow shelf sea, with an average depth of 230 metres, and is an important site for both fishing and hydrocarbon exploration. Novaya Zemlya, an extension of the part of the Ural Mountains. The southern half of the Barents Sea, including the ports of Murmansk, in September, the entire Barents Sea is more or less completely ice-free. Until the Winter War, Finlands territory reached to the Barents Sea, with the harbor at Petsamo being Finlands only ice-free winter harbor. There are three types of water masses in the Barents Sea, salty Atlantic water from the North Atlantic drift, cold Arctic water from the north, and warm. Between the Atlantic and Polar waters, a front called the Polar Front is formed, the lands of Novaya Zemlya attained most of their early Holocene coastal deglaciation approximately 10,000 years before present.
The International Hydrographic Organization defines the limits of the Barentsz Sea as follows, On the west, on the northwest, The eastern shore of West Spitzbergen, Hinlopen Strait up to 80° latitude north and east coasts of North-East Land to Cape Leigh Smith. On the north, Cape Leigh Smith across the Islands Bolshoy Ostrov and Victoria, on the east, Cape Kohlsaat to Cape Zhelaniya and southwest coast of Novaya Zemlya to Cape Kussov Noss and thence to western entrance Cape, Dolgaya Bay on Vaigach Island. Through Vaigach Island to Cape Greben, thence to Cape Belyi Noss on the mainland, on the south, The northern limit of the White Sea. Other islands in the Barents Sea include Chaichy and Timanets, most of its geological history is dominated by extensional tectonics, caused by the collapse of the Caledonian and Uralian orogenic belts and the break-up of Pangaea. These events created the rift basins that dominate the Barents Shelf, along with various platforms. Due to the North Atlantic drift, the Barents Sea has a high biological production compared to other oceans of similar latitude.
The spring bloom of phytoplankton can start quite early close to the ice edge, the phytoplankton bloom feeds zooplankton such as Calanus finmarchicus, Calanus glacialis, Calanus hyperboreus, Oithona spp. and krill. The zooplankton feeders include young cod, polar cod, the capelin is a key food for top predators such as the north-east Arctic cod, harp seals, and seabirds such as common guillemot and Brunnichs guillemot. The fisheries of the Barents Sea, in particular the cod fisheries, are of importance for both Norway and Russia. There is a genetically distinct polar bear population associated with the Barents Sea and its eastern corner, in the region of the Pechora Rivers estuary, has been known as Pechorskoye Morye, that is, Pechora Sea. This sea was given its present name in honor of Willem Barentsz, Barentsz was the leader of early expeditions to the far north, at the end of the sixteenth century
Strait of Magellan
The Strait of Magellan, called the Straits of Magellan, is a navigable sea route separating mainland South America to the north and Tierra del Fuego to the south. The strait is the most important natural passage between the Atlantic and Pacific oceans, the Strait of Magellan was called the Dragons Tail, and there were the Cape of Good Hope and the coast of Africa. Ferdinand Magellan, a Portuguese explorer and navigator in the service of Charles I of Spain, the fleet would become known as the Armada de las Molucas or Fleet of the Moluccas. The expeditionary fleet of five ships set sail from Sanlúcar de Barrameda on September 20,1519, before the passage of the Strait, Álvaro de Mesquita became captain of the San Antonio, and Duarte Barbosa of Victoria. Later, Serrão became captain of Concepcion, San Antonio, charged to explore Magdalen Sound, failed to return to the fleet, instead sailing back to Spain under Estêvão Gomes who imprisoned the captain Mesquita. Magellans ships entered the strait on November 1,1520, All Saints Day, magellans chronicler, Antonio Pigafetta, called it the Patagonian Strait, and others Victoria Strait, commemorating the first ship entering it.
Within seven years it was being called Estrecho de Magallanes in honor of Magellan, the Spanish Empire and the Captaincy General of Chile used it as the southern boundary of their territory. The first Spanish colony was established in 1584 by Pedro Sarmiento de Gamboa and these towns suffered severe food shortages, and when the English navigator Sir Thomas Cavendish landed at the site of Rey Don Felipe in 1587, he found only ruins of the settlement. He renamed the place Port Famine, other early explorers included Francis Drake. In February 1696 the first French expedition, under the command of M. de Gennes reached the Strait of Magellan, the expedition is described by the young French explorer and hydrographer François Froger in his A Relation of a Voyage. A report on the survey was presented at two meetings of the Geographical Society of London in 1831, Chile took possession of the Strait of Magellan on May 23,1843. President Bulnes of Chile ordered this expedition after consulting the Chilean libertador Bernardo OHiggins, the first Chilean settlement was Fuerte Bulnes, situated in a forested zone on the north side of the strait.
Fuerte Bulnes was abandoned, and in 1848 the city of Punta Arenas was founded farther north where the Magellanic forests meets the Patagonian plains. In Tierra del Fuego, across the strait from Punta Arenas, Argentina effectively recognized Chilean sovereignty over the Strait of Magellan in the Boundary treaty of 1881 between Chile and Argentina. Argentina had previously claimed all of the strait, or at least the third of it. In 1840 the Pacific Steam Navigation Company was the first to use steamships for commercial traffic in the strait, until the Panama Canal opened in 1914, the Strait of Magellan was the main route for steamships traveling from the Atlantic Ocean to the Pacific. Sailing ships, partly because of winds and currents in the strait, generally preferred the Drake Passage. The strait is approximately 570 kilometres long and about 2 kilometres wide at its narrowest point, the northwestern portion of the strait is connected with other sheltered waterways via the Smyth Channel
The Adriatic Sea /ˌeɪdriˈætᵻk/ is a body of water separating the Italian Peninsula from the Balkan peninsula and the Apennine Mountains from the Dinaric Alps and adjacent ranges. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto to the northwest, the countries with coasts on the Adriatic are Albania and Herzegovina, Greece, Italy and Slovenia. The Adriatic contains over 1,300 islands, mostly located along its eastern, Croatian and it is divided into three basins, the northern being the shallowest and the southern being the deepest, with a maximum depth of 1,233 metres. The Otranto Sill, a ridge, is located at the border between the Adriatic and Ionian Seas. The prevailing currents flow counterclockwise from the Strait of Otranto, along the eastern coast, tidal movements in the Adriatic are slight, although larger amplitudes are known to occur occasionally. The Adriatics salinity is lower than the Mediterraneans because the Adriatic collects a third of the water flowing into the Mediterranean.
The surface water temperatures range from 30 °C in summer to 12 °C in winter. The Adriatic Sea sits on the Apulian or Adriatic Microplate, which separated from the African Plate in the Mesozoic era, the plates movement contributed to the formation of the surrounding mountain chains and Apennine tectonic uplift after its collision with the Eurasian plate. In the Late Oligocene, the Apennine Peninsula first formed, separating the Adriatic Basin from the rest of the Mediterranean, all types of sediment are found in the Adriatic, with the bulk of the material transported by the Po and other rivers on the western coast. The western coast is alluvial or terraced, while the eastern coast is indented with pronounced karstification. There are dozens of protected areas in the Adriatic, designed to protect the seas karst habitats. The sea is abundant in flora and fauna—more than 7,000 species are identified as native to the Adriatic, many of them endemic and threatened ones. The Adriatics shores are populated by more than 3.5 million people, the earliest settlements on the Adriatic shores were Etruscan and Greek.
By the 2nd century BC, the shores were under Romes control, following Italian unification, the Kingdom of Italy started an eastward expansion that lasted until the 20th century. Following World War I and the collapse of Austria-Hungary and the Ottoman Empire, the former disintegrated during the 1990s, resulting in four new states on the Adriatic coast. Italy and Albania agreed on their maritime boundary in 1992, Fisheries and tourism are significant sources of income all along the Adriatic coast. Adriatic Croatias tourism industry has grown faster economically than the rest of the Adriatic Basins, maritime transport is a significant branch of the areas economy—there are 19 seaports in the Adriatic that each handle more than a million tonnes of cargo per year. The largest Adriatic seaport by annual cargo turnover is the Port of Trieste, in the southeast, the Adriatic Sea connects to the Ionian Sea at the 72-kilometre wide Strait of Otranto
The Greenland Sea is often defined as part of the Arctic Ocean, sometimes as part of the Atlantic Ocean. However, definitions of the Arctic Ocean and its seas tend to be imprecise or arbitrary, in general usage the term Arctic Ocean would exclude the Greenland Sea. In oceanographic studies the Greenland Sea is considered part of the Nordic Seas, the Nordic Seas are the main connection between the Arctic and Atlantic oceans and, as such, could be of great significance in a possible shutdown of thermohaline circulation. In oceanography the Arctic Ocean and Nordic Seas are often referred to collectively as the Arctic Mediterranean Sea, the sea has Arctic climate with regular northern winds and temperatures rarely rising above 0 °C. The West Ice forms in winter in the Greenland Sea, north of Iceland and it is a major breeding ground of harp seal and hooded seal that has been used for seal hunting for more than 200 years. The International Hydrographic Organization defines the limits of the Greenland Sea as follows, a line joining the Northernmost point of Spitzbergen to the Northernmost point of Greenland.
The West coast of West Spitzbergen, a line joining Straumnes to Cape Nansen in Greenland. The East and Northeast coast of Greenland between Cape Nansen and the northernmost point, while the sea is known for millennia, its first scientific investigations were carried out in 1876–1878 within the Norwegian North-Atlantic Expedition. Since then, many countries, mostly Norway and Russia have sent scientific expeditions to the area, the complex water current system was detailed in 1909 by the Fridtjof Nansen. The Greenland Sea was a hunting ground for the whaling industry for 300 years, until 1911. At that point, the formerly rich whale population here, was so depleted that the industry was no longer profitable, the remaining whales of the Greenland Sea has been protected ever since, but the populations had not shown any proof of significant regeneration. In the last 20 years, polar biologists reports an increase in the local bowhead whale population and in 2015, arctic scientists discovered a surprising abundance of them in a small area.
These results may be interpreted as an sign of a beginning recovery for this particular species. The inuit hunted whales on a scale in the Greenland Sea since the fifteenth century. The Greenland Sea is bounded to the west by the island of Greenland, to the southeast, behind the Jan Mayen island lies the vast expanse of the Norwegian Sea, of which Greenland Sea may be considered an extension. Across the Fram Strait to the northeast, the sea is delimited by the Svalbard archipelago, the bottom of the Greenland Sea is a depression bounded to the south by the underwater Greenland-Iceland ridge and to the east by the Mohns Ridge and Knipovich Ridge. To the west, the bottom rises first slowly, but rapidly toward the wide Greenland coastal strip, silts fill the submarine hollows and gorges, silty sands, gravel and other products of erosion coat the shelves and ridges. Of those, only the Svalbard islands are inhabited, and Jan Mayen has only temporal military staff, several radio and meteorological stations operate on the island nowadays
A drainage basin or catchment area is any area of land where precipitation collects and drains off into a common outlet, such as into a river, bay, or other body of water. Drainage basins connect into other drainage basins at elevations in a hierarchical pattern, with smaller sub-drainage basins. Other terms used to describe drainage basins are catchment, catchment basin, drainage area, river basin and water basin. In closed drainage basins the water converges to a point inside the basin, known as a sink, which may be a permanent lake. The drainage basin acts as a funnel by collecting all the water within the covered by the basin. Each drainage basin is separated topographically from adjacent basins by a perimeter, drainage basins are similar but not identical to hydrologic units, which are drainage areas delineated so as to nest into a multi-level hierarchical drainage system. Hydrologic units are defined to allow multiple inlets, outlets, or sinks, in a strict sense, all drainage basins are hydrologic units but not all hydrologic units are drainage basins.
Drainage basins of the oceans and seas of the world. Grey areas are endorheic basins that do not drain to the oceans, the following is a list of the major ocean basins, About 48. 7% of the worlds land drains to the Atlantic Ocean. The two major mediterranean seas of the world flow to the Atlantic, The Caribbean Sea and Gulf of Mexico basin includes most of the U. S. The Mediterranean Sea basin includes much of North Africa, east-central Africa, Southern and Eastern Europe and the areas of Israel, Lebanon. Just over 13% of the land in the world drains to the Pacific Ocean, the Indian Oceans drainage basin comprises about 13% of Earths land. It drains the eastern coast of Africa, the coasts of the Red Sea and the Persian Gulf, the Indian subcontinent, antarctica comprises approximately eight percent of the Earths land. The five largest river basins, from largest to smallest, are the basins of the Amazon, the Río de la Plata, the Congo, the Nile, and the Mississippi. The three rivers that drain the most water, from most to least, are the Amazon, endorheic drainage basins are inland basins that do not drain to an ocean.
Around 18% of all land drains to endorheic lakes or seas or sinks, the largest of these consists of much of the interior of Asia, which drains into the Caspian Sea, the Aral Sea, and numerous smaller lakes. Some of these, such as the Great Basin, are not single drainage basins but collections of separate, in endorheic bodies of standing water where evaporation is the primary means of water loss, the water is typically more saline than the oceans. An extreme example of this is the Dead Sea, drainage basins have been historically important for determining territorial boundaries, particularly in regions where trade by water has been important
Patagonia is a sparsely populated region located at the southern end of South America, shared by Argentina and Chile. The region comprises the section of the Andes mountains as well as the deserts, steppes. Patagonia has two coasts, a western one towards the Pacific Ocean and an eastern one towards the Atlantic Ocean, the Colorado and Barrancas rivers, which run from the Andes to the Atlantic, are commonly considered the northern limit of Argentine Patagonia. The archipelago of Tierra del Fuego is sometimes included as part of Patagonia, most geographers and historians locate the northern limit of Chilean Patagonia at Reloncaví Estuary. The name Patagonia comes from the word used by Magellan in 1520 to describe the native people that his expedition thought to be giants. It is now believed that the people he called the Patagons were Tehuelches, the hypothesis was accepted and published in the New Review of Spanish Philology in the 2011 article. In the hollows of the plains are ponds or lakes of fresh and brackish water, towards the Andes, the shingle gives place to porphyry and basalt lavas, animal life becomes more abundant and vegetation more luxuriant.
It is characteristic of the flora of the western coast, and consist principally of southern beech and conifers. Among the depressions by which the plateau is intersected transversely, the ones are the Gualichu, south of the Río Negro, the Maquinchao and Valcheta, the Senguerr. There, erosion which is caused principally by the sudden melting, best in evidence where in contact with folded Cretaceous rocks which are uplifted by the Cenozoic granite. It generally separates the plateau from the first lofty hills, the ridges generally called the pre-Cordillera, to the west of these, a similar longitudinal depression extends all along the foot of the snowy Andean Cordillera. This latter depression contains the richest and most fertile land of Patagonia, Lake basins along the Cordillera were excavated by ice-streams, including Lake Argentino and Lake Fagnano, as well as coastal bays such as Bahía Inútil. There have been discrepancies among geologists on the origin of the Patagonian landmass, víctor Ramos has proposed that the Patagonian landmass originated as an allochtonous terrane that separated from Antarctica and docked in South America 250 to 270 Ma in the Permian era.
A2014 study by Robert John Pankhurst and coworkers reject any idea of a far-travelled Patagonia claiming it is likely of parautochtonous origin, the Mesozoic and Cenozoic deposits have revealed a most interesting vertebrate fauna. The Patagonian Myolania belongs to the Upper Chalk, having been associated with remains of Dinosauria. In the Cenozoic marine formation, a number of cetaceans has been discovered. At a state level, Patagonia lies inside two countries and Argentina, both countries have organised their Patagonian territories into non-equivalent administrative subdivisions and departments in Argentina, and regions and communes in Chile. Being a unitary state Chiles first level administrative divisions—the regions—enjoy far less autonomy than Argentine provinces, Argentine provinces have elected governors and parliaments, while Chilean regions have government-appointed intendants