Amazon River
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- Portuguese:
- Rio Amazonas
- Spanish:
- Río Amazonas
- Also called:
- Río Marañón and Rio Solimões
Where is the Amazon River located?
The Amazon River is located in the northern portion ofSouth America, flowing from west to east. The river system originates in theAndes Mountains ofPeru and travels throughEcuador,Colombia,Venezuela,Bolivia, andBrazil before emptying into theAtlantic Ocean. Roughly two-thirds of the Amazon’s main stream is within Brazil.
How long is the Amazon River?
Most researchers believe that it is at least 4,000 miles (6,400 km) long. However, no definitive measure is available because no one is entirely sure where the Amazon ends and begins. Given the complexity of the river system, much of which is in remote areas, researchers have proposed several locations inPeru as its source. As to its end point, the Amazon has three outlets to theAtlantic Ocean: two on the northern side ofMarajó Island inBrazil and one to the island’s south that joins thePará River. Scientists have typically selected one of the northern outlets, since the Pará is an estuary of theTocantins River, which is technically separate from the Amazon.
Why is the Amazon River famous?
The Amazon is well known for a number of reasons. It is the greatest river ofSouth America and the largest drainage system in the world in terms of the volume of its flow and the area of its basin. While there is some debate about its length, the river is generally believed to be at least 4,000 miles (6,400 km) long, which makes it the second longest river in the world after theNile River inAfrica. The Amazon is also famous for the rainforest found along its shores. TheAmazon Rainforest represents about half of Earth’s remaining rainforest and is the world’s largest biological reservoir, home to more than a million species.
What animals live in the Amazon River?
About 2,500 fish species have been found within the Amazon system, but many more remain unidentified. Among the more important commercial species are thepirarucu, one of the world’s largest freshwater fish, and various giantcatfish. The small flesh-eatingpiranha generally feeds on other fish but may attack any animal or human that enters the water. Other animals includecaiman, riverturtles,river dolphins, andmanatees. The Amazon is also home to the semiaquaticcapybara, the largest rodent in the world, and thenutria (or coypu).
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Amazon River, the greatestriver ofSouth America and the largestdrainage system in the world in terms of the volume of its flow and the area of itsbasin. The total length of the river—as measured from the headwaters of theUcayali-Apurímac river system in southernPeru—is at least 4,000 miles (6,400 km), which makes it slightly shorter than theNile River but still the equivalent of the distance fromNew York City toRome. Its westernmost source is high in theAndes Mountains, within 100 miles (160 km) of thePacific Ocean, and its mouth is in theAtlantic Ocean, on the northeastern coast ofBrazil. However, both the length of the Amazon and its ultimate source have been subjects of debate since the mid-20th century, and there are those who claim that the Amazon is actually longer than the Nile. (See belowThe length of the Amazon.)
ThevastAmazon basin (Amazonia), the largest lowland inLatin America, has an area of about 2.7 million square miles (7 million square km) and is nearly twice as large as that of theCongo River, theEarth’s other great equatorial drainage system. Stretching some 1,725 miles (2,780 km) from north to south at its widest point, the basin includes the greater part ofBrazil andPeru, significant parts ofColombia,Ecuador, andBolivia, and a small area ofVenezuela; roughly two-thirds of the Amazon’s main stream and by far the largest portion of its basin are within Brazil. The Tocantins-Araguaiacatchment area inPará state covers another 300,000 square miles (777,000 square km). Although considered a part ofAmazonia by the Brazilian government and in popular usage, it is technically a separate system. It is estimated that about one-fifth of all the water that runs off Earth’s surface is carried by the Amazon. The flood-stagedischarge at the river’s mouth is four times that of the Congo and more than 10 times the amount carried by theMississippi River. This immense volume of fresh water dilutes the ocean’s saltiness for more than 100 miles (160 km) from shore.
The extensive lowland areas bordering the main river and its tributaries, calledvárzeas (“floodplains”), are subject to annual flooding, with consequentsoil enrichment; however, most of the vast basin consists of upland, well above the inundations and known asterra firme. More than two-thirds of the basin is covered by an immense rainforest, which grades into dryforest andsavanna on the higher northern and southern margins and into montane forest in the Andes to the west. TheAmazon Rainforest, which represents about half of the Earth’s remaining rainforest, alsoconstitutes its single largest reserve of biological resources.
Since the later decades of the 20th century, the Amazon basin has attracted international attention because human activities have increasingly threatened theequilibrium of the forest’s highly complex ecology.Deforestation has accelerated, especially south of the Amazon River and on the piedmont outwash of the Andes, as newhighways and air transport facilities have opened the basin to atidal wave of settlers, corporations, and researchers. Significant mineral discoveries have brought further influxes of population. Theecological consequences of such developments, potentially reaching well beyond the basin and even gaining worldwide importance, have attracted considerable scientific attention (seeSidebar: Status of the World’s Tropical Forests).
The first European to explore the Amazon, in 1541, was the Spanish soldierFrancisco de Orellana, who gave the river its name after reporting pitched battles with tribes of female warriors, whom he likened to the Amazons ofGreek mythology. Although the name Amazon is conventionally employed for the entire river, in Peruvian and Braziliannomenclature it properly is applied only to sections of it. In Peru the upper main stream (fed by numerous tributaries flowing from sources in the Andes) down to theconfluence with theUcayali River is calledMarañón, and from there to the Brazilian border it is calledAmazonas. In Brazil the name of the river that flows from Peru to its confluence with theNegro River isSolimões; from the Negro out to the Atlantic the river is called Amazonas.
