Amazon River Portuguese Rio Arnazonas River, northern South America. It is the largest river in the world in volume and area of drainage basin, and only the NILE RIVER of northeastern Africa exceeds it in length. It originates within 100 mi (160 km) of the Pacific Ocean in the Peruvian ANDES MOUNTAINS and flows almost 4,000 mi (6,400 km) across northern Brazil into the Atlantic Ocean. Its Peruvian length is called the Maranon River; the stretch of river from the Brazilian border to the mouth of the NEGRO RIVER is the Solimoes River. Its more than 1,000 known tributaries rise in the Guiana Highlands, the Brazilian Highlands, and (principally) the Andes; 7 of these are longer than 1,000 mi (1,600 kin), and the MADEIRA RIVER is longer than 2,000 mi (3,200 km). The Amazon River is one of the longest two rivers on Earth, the Nile River in Africa being the other. The Amazon has by far the greatest total flow of any river, carrying more than the Mississippi, Nile, and Yangtze rivers combined. It also has the largest drainage area of any river system. It may be correctly stated that the Nile is the longest river, while the Amazon is the strongest.
The Amazon can accommodate large freighters as far upriver as the city of MANAUS, Braz., 1,000 mi (1,600 km) from the Atlantic. The first European descent was made by Francisco de Orellana in 154 1; he is said to have given the river its name after reporting battles with tribes of women, whom he likened to the AMAZONS of Greek legend. Pedro Teixeira achieved the first ascent in 1637 39, but the river remained little explored until the mid 19th century. Many indigenous peoples originally lived along the river, but they moved inland as exploring parties and raiders sought to enslave them. The river was opened to world shipping in the 1860s; traffic increased exponentially with the coming of the rubber trade, which reached its height c. 19 10 but soon declined. It is the site of the world's most extensive rainforest and hosts an extraordinary diversity of birds and wildlife. Since the 1960s the effects of economic exploitation on the region's ecology and the erosion of the rainforest have generated worldwide concern.
The quantity of fresh water released to the Atlantic Ocean is enormous: 184,000 m³ per second (6.5 million ft³/s) in the rainy season. Indeed, the Amazon is responsible for a fifth of the total volume of fresh water entering the oceans worldwide. It is said that offshore of the mouth of the Amazon potable water can be drawn from the ocean while still out of sight of the coastline, and the salinity of the ocean is notably lower a hundred miles out to sea. Teeming with exotic wildlife, indigenous cultures and impressive natural wonders, the region also affords visitors a wide variety of experiences impossible to duplicate anywhere else on earth. And sailing the Amazon aboard the ultra luxury Seabourn Pride is a far cry from the travails of early explorers, and from the rather spartan conditions one might expect even today in the heart of the Brazilian forest.Several
Seasonal rains give rise to extensive floods along the course of the Amazon and its tributaries. The average depth of the river in the height of the rainy season is 40 m (120 ft) and the average width can be nearly twenty-five miles. It starts to rise in November, and increases in volume until June, then falls until the end of October. The rise of the Negro branch is not synchronous; the rainy season does not commence in its valley until February or March. By June it is full, and then it begins to fall with the Amazon. The Madeira rises and falls two months earlier than the Amazon.
The abundance of water in the Amazon basin is due to the fact that much of this lies in the region below the Intertropical convergence zone, where rainfall is at a maximum. Also, the basin lies in the Trade Wind zone, where moisture from the Atlantic is pushed westwards, and eventually forced to rise over the Andes, the second tallest mountain range on Earth, where the moist air cools and precipitates water. This combination creates more rainfall over a large river basin than anywhere else on the planet.
In the rainy season, the Amazon inundates the country throughout its course to the extent of several hundred thousand square miles, covering the flood-plain, called vargem. The flood-levels are, in some places, from 12 to 15 m (40 to 50 ft) higher than levels during the dry season. During the flood, the level at Iquitos is 6 m (20 ft); at Teffe, it is 15 m (45 ft); near Obidos, 11 m (35 ft); and at Para, 4 m (12 ft), above the low-water extreme seen during the dry season.
The breadth of the Amazon in some places is as much as 6 to 10 km (4 to 6 mi) from one bank to the other. At some points, for long distances, the river divides into two main streams with inland and lateral channels, all connected by a complicated system of natural canals, cutting the low, flat igapo lands, which are never more than 5 m (15 ft) above low river, into almost numberless islands.
At the narrows of Óbidos, 600 km (400 mi) from the sea, the Amazon narrows, flowing in a single streambed, a mile (1.6 km) wide and over 200 ft (60 m). deep, through which the water rushes toward the sea at the speed of 6 to 8 km/h (4 to 5 mph).
From the village of Canaria at the great bend of the Amazon to the Negro 1,000 km (600 mi) downstream, only very low land is found, resembling that at the mouth of the river. Vast areas of land in this region are submerged at high water, above which only the upper part of the trees of the sombre forests appear. Near the mouth of the Rio Negro to Serpa, nearly opposite the river Madeira, the banks of the Amazon are low, until approaching Manaus, they rise to become rolling hills. At Óbidos, a bluff 17 m (56 ft) above the river is backed by low hills. The lower Amazon seems to have once been a gulf of the Atlantic Ocean, the waters of which washed the cliffs near Óbidos.
The waters of the Amazon support a diverse range of wildlife. Along with the Orinoco, the river is one of the main habitats of the Boto, also known as the Amazon River Dolphin. The largest species of river dolphin, it can grow to lengths of up to 2.6 m.
Also present in large numbers are the notorious Piranha, carnivorous fish which congregate in large schools, and may attack livestock and even humans. Although many experts believe their reputation for ferocity is unwarranted, a school of piranha was apparently responsible for the deaths of up to 300 people when their boat capsized near Obidos in 1981.
The Anaconda snake is found in shallow waters in the Amazon basin. One of the world's largest species of snake, the Anaconda spends most of its time in the water, with just its nostrils above the surface. Anacondas have been known very occasionally to attack fishermen.
The river also supports thousands of species of fish, as well as crabs and turtles.
An Amazon cruise is the ultimate jungle adventure. From the endless green carpet of tree tops that make up the rainforest to the exotic wildlife that inhabits the waters of the mighty Amazon River, an Amazon cruise will reveal an awe-inspiring ecosystem that is both captivating and educational.
When choosing your Amazon cruise you'll find that you are presented with two distinct choices of cruise vacation. If you're looking to tour the Amazon from the comfort of a large luxury cruise liner, Amazon cruises leaving from the city of Manaus in the heart of the Amazon Rainforest are ideal.
Manaus, at the confluence of the Negro and Amazon Rivers represents the furthest point upstream that large Amazon cruise liners can venture. Here, the Amazon is 11kms wide, and it is the main port from where many of the larger cruise liners set sail..
The second Amazon cruise option offers travelers the opportunity to explore the head of the Amazon River in Eastern Peru. Here, some 6,000kms west of the River's exit point into the Atlantic Ocean, the Amazon ecosystem is at its most diverse..
The river is much narrower here, so Amazon cruise crafts are smaller, taking the form of riverboats with a capacity to hold no more than 50 or 60 passengers. The favored port of departure and return on a Peru Amazon cruise is located at the city of Iquitos. Most passengers arrive at Iquitos by air on an internal flight from Lima - the capital of Peru.