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Amazon River


Biggest River on Earth ::--|| 1.Nile River|| 2.Amazon River|| 3.Yangtze River|| 4.Missisipi River|| 5.Yenisei River|| 6.Yellow River|| 7.Ob River|| 8.Parana River|| 9.Congo River|| 10.Amur River|| 11.Lena River|| 12.Mekong River|| 13.Mackenzie River|| 14.Niger River|| 15.Murray/Darling River|| 16.Tocantins River|| 17.Volga River|| 18.Purus River|| 19.Madeira River|| 20.Sao Francisco River||List of River's.||


mouth of amazon river
Mouth of the Amazon River
Countries
Brazil, Colombia, Peru
Region
South America
Tributaries
- left
Marañón, Japurá/Caquetá, Rio Negro/Guainía,Putumayo
- right
Ucayali, Purus, Madeira, Xingu, Tocantins
City
Iquitos (Peru); Leticia (Colombia); Manaus (Brazil), Santarém and Belém do Pará (Brazil), Macapa (Brazil)
Source
Andes Mountains
- location
Nevado Mismi, Arequipa, Peru
- elevation
5,170 m (16,962 ft)
- coordinates
15°31′5″S 71°45′55″W
Mouth
Atlantic Ocean
- elevation
0 m (0 ft)
- coordinates
0°10′0″S 49°0′0″W 
Length
6,400 km (4,000 mi) approx.
Basin
7,050,000 km2 (2,720,000 sq mi) approx.
Discharge
- average
209,000 m3/s (7,381,000 cu ft/s) approx.
amazon river map
Map showing the Amazon drainage basin with the Amazon River highlighted


Amazon River

The Amazon of South America is the second longest river in the world and by far the largest by waterflow with an average discharge greater than the next seven largest rivers combined (not including Madeira and Rio Negro, which are tributuaries of the Amazon). The Amazon, which has the largest drainage basin in the world, about 7,050,000 square kilometres (2,720,000 sq mi), accounts for approximately one-fifth of the world's total river flow.
In its upper stretches, above the confluence of the Negro River, the Amazon is called Solimões in Brazil; however, in Peru, Colombia and Ecuador, as well as the rest of the Spanish-speaking world, the river is generally called the Amazon downstream from the confluence of the Marañón and Ucayali rivers in Peru. The Ucayali-Apurímac river system is considered the main source of the Amazon.
The width of the Amazon varies between 1.6 and 10 kilometres (1.0 and 6.2 mi) at low stage, but expands during the wet season to 48 kilometres (30 mi) or more. The river enters the Atlantic Ocean in a broad estuary about 240 kilometres (150 mi) wide. The mouth of the main stem is 80 kilometres (50 mi). Because of its vast dimensions, it is sometimes called The River Sea. At no point is the Amazon crossed by a bridge. This is not because of its huge dimensions; in fact, for most of its length (which is 4,080 miles), the Amazon's width is well within the capability of modern engineers to bridge. However, the bulk of the river flows through tropical rainforest, where there are few roads or cities, limiting the need for crossings.



Drainage area

The Amazon Basin, the largest drainage basin in the world, covers about 30% of South America, an area of approximately 7,050,000 square kilometres (2,720,000 sq mi). It gathers its waters from 5 degrees north latitude to 20 degrees south latitude. Its most remote sources are found on the inter-Andean plateau, just a short distance from the Pacific Ocean.
The Amazon River and its tributaries are characterized by extensive forested areas that become flooded every rainy season. Every year the river rises more than 9 metres (30 ft), flooding the surrounding forests, known as várzea ("flooded forests"). The Amazon's flooded forests are the most extensive example of this habitat type in the world. In an average dry season, 110,000 square kilometres (42,000 sq mi) of land are water-covered, while in the wet season, the flooded area of the Amazon Basin rises to 350,000 square kilometres (140,000 sq mi).
The quantity of water released by the Amazon to the Atlantic Ocean is enormous: up to 300,000 cubic metres per second (11,000,000 cu ft/s) in the rainy season, with an average of 209,000 cubic metres per second (7,400,000 cu ft/s) from 1973 to 1990. The Amazon is responsible for about 20% of the Earth's fresh water entering the ocean. The river pushes a vast plume of fresh water into the ocean. The plume is about 400 kilometres (250 mi) long and between 100 and 200 kilometres (62 and 120 mi) wide. The fresh water, being lighter, overrides the salty ocean, diluting the salinity and altering the color of the ocean surface over an area up to 1,000,000 square miles (2,600,000 km2) large. For centuries ships have reported fresh water near the Amazon's mouth yet well out of sight of land in what otherwise seemed to be the open ocean.
The Atlantic has sufficient wave and tidal energy to carry most of the Amazon's sediments out to sea, thus the Amazon does not form a true delta. The great deltas of the world are all in relatively protected bodies of water while the Amazon empties directly into the turbulent Atlantic.
The tidal bore is the reason the Amazon does not have a protruding delta; the ocean rapidly carries away the vast volume of silt carried by the Amazon, making it impossible for a delta to grow past the shoreline.
There is a natural water union between the Amazon and the Orinoco basins, the so-called Casiquiare canal. The Casiquiare is a river distributary of the upper Orinoco, which flows southward into the Rio Negro, which in turn flows into the Amazon. The Casiquiare is the largest river on the planet that links two major river systems, a so-called bifurcation.

The Amazon river Origins

The Amazon river has a series of major river systems in Colombia, Ecuador and Peru, some of which flow into the Marañón and Ucayali, others directly into the Amazon proper. Among others, these include the following rivers: Putumayo, Caquetá, Vaupés, Guainía, Morona, Pastaza, Nucuray, Urituyacu, Chambira, Tigre, Nanay, Napo, and Huallaga.
The most distant source of the Amazon was established in 1996, 2001, 2007, and 2008, as a glacial stream on a snowcapped 5,597 m (18,363 ft) peak called Nevado Mismi in the Peruvian Andes, roughly 160 km (99 mi) west of Lake Titicaca and 700 km (430 mi) southeast of Lima. The waters from Nevado Mismi flow into the Quebradas Carhuasanta and Apacheta, which flow into the Río Apurímac which is a tributary of the Ucayali which later joins the Marañón to form the Amazon proper. While the Ucayali–Marañón confluence is the point at which most geographers place the beginning of the Amazon proper, in Brazil the river is known at this point as the Solimões das Águas. Further downriver from that confluence the darkly colored waters of the Rio Negro meet the sandy colored Rio Solimões, and for over 6 km (4 mi) these waters run side by side without mixing.
After the confluence of Río Apurímac and Ucayali, the river leaves Andean terrain and is instead surrounded by floodplain. From this point to the Marañón, some 1,600 km (990 mi), the forested banks are just out of water, and are inundated long before the river attains its maximum flood stage. The low river banks are interrupted by only a few hills, and the river enters the enormous Amazon Rainforest.
The river systems and flood plains in Brazil, Peru, Ecuador, Colombia and Venezuela, whose waters drain into the Solimões and its tributaries are called the "Upper Amazon". The Amazon River proper runs mostly through Brazil and Peru, it is part of the border between Colombia and Perú, and it has tributaries reaching into Venezuela, Colombia, Ecuador, and Bolivia.

Dispute regarding length

While debate as to whether the Amazon or the Nile is the world's longest river has gone on for many years, the historic consensus of geographic authorities has been to regard the Amazon as the second longest river in the world, with the Nile being the longest. However, the Amazon has been measured by different geographers as being anywhere between 6,259 and 6,800 kilometres (3,889 and 4,200 mi) long. It is often said to be "at least" 6,400 kilometres (4,000 mi) long. The Nile is reported to be anywhere from 5,499 to 6,690 kilometres (3,417 to 4,160 mi). Often it is said to be "about" 6,650 kilometres (4,130 mi) long. There are many factors that can affect these measurements.
A study by Brazilian scientists concluded that the Amazon is actually longer than the Nile. Using Nevado Mismi, which in 2001 was labeled by the National Geographic Society as the Amazon's source, these scientists made new calculations of the Amazon's length. They calculated the Amazon's length as 6,992 kilometres (4,345 mi). Using the same techniques they calculated the length of the Nile as 6,853 kilometres (4,258 mi), which is longer than previous estimates but still shorter than the Amazon. They made it possible by measuring the Amazon downstream to the beginning of the tidal estuary of Canal do Sul and then, after a sharp turn back, following tidal canals surrounding the isle of Marajó and finally including the marine Waters of the Río Pará bay in its entire length. Guido Gelli, director of science at the Brazilian Institute of Geography and Statistics (IBGE), told the Brazilian TV network Globo in June 2007 that it could be considered as a fact that the Amazon was the longest river in the world. However, other geographers have had access to the same data since 2001, and a consensus has yet to emerge to support the claims of these Brazilian scientists. As of 2010 the length of both the Amazon and the Nile remains open to interpretation and continued debate.
Scientists have discovered the longest underground river in the world, in Brazil, running for a length of 6,000 km at a depth of nearly 4 km. It flows from the Andean foothills to the Atlantic coast in a nearly west-to-east direction like the Amazon River. The discovery was made public at a recent meeting of the Brazilian Geophysical Society in Rio de Janeiro. The river ‘Hamza,' named after the discoverer, an Indian-born scientist Valiya Mannathal Hamza who is working with the National Observatory at Rio, makes it the first and geologically unusual instance of a twin-river system flowing at different levels of the earth's crust in Brazil. If the slowing down of certain seismic waves caused by the damp spot helped uncover the underground ocean, the unusual temperature variation with depth measured in 241 inactive oil wells helped locate the subterranean river. Except for the flow direction, the Amazon and the Hamza have very different characteristics. The most obvious ones are their width and flow speed. While the former is 1 km to 100 km wide, the latter is 200 km to 400 km in width. But the flow speed is five meters per second in the Amazon and less than a millimeter per second speed in the Hamza.
Several geological factors have played a vital role in the formation and existence of these subterranean water bodies. The underground ocean, discovered in 2007, has been formed when the plate carrying the Pacific Ocean bottom gets dragged and ends up under the continental plate. Water at such depths would normally escape upwards but the unusual conditions that exist along the eastern Pacific Rim allow the moisture to remain intact. In the case of the Hamza, the porous and permeable sedimentary rocks behave as conduits for the water to sink to greater depths. East-west trending faults and the karst topography present along the northern border of the Amazon basin may have some role in supplying water to the river. If the impermeable rocks stop the vertical flow, the west to east gradient of the topography directs it to flow towards the Atlantic Ocean. Unlike the Hamza, the 153 km-long underground river in Mexico's Yucatán Peninsula and the 8.2 km-long Cabayugan River in the Puerto Princesa Subterranean River National Park in the Philippines have come into being thanks to the karst topography. Water in these places drills its way downward by dissolving the carbonate rock to form an extensive underground river system.

 

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