The Amazon River is the largest river
on Earth in terms of watershed area, number of tributaries
and volume of water discharged. Its water volume accounts
for approximately 1/5 of the World's total river flow;
larger, indeed, than the combined flow of the next top
ten largest rivers flowing into the ocean.
There is not complete agreement regarding
the length of the Amazon river, as measurements vary
according to methodology. Its length, though, lies anywhere
between 6,259 km (3,889 miles) and 6,800 km (4,225 miles).
It has over 1,000 tributaries, 8 of which are over 2,000
kilometres.
The source of the Amazon river,
according to a National Geographic Society expedition,
is to be found in a slope of Nevado Mismi --a 18,363-foot-high
(5,597-meter) mountain in the southern Peruvian Andes.
The river though is not formally known as Amazon until
the confluence of two of its main tributaries, the Ucayali
river and the Marañón river.