Sometime during the Pleistocene Epoch (about 2,600,000 to 11,700 years ago) an outlet to the Atlantic was established, and the great river and its tributaries became deeply entrenched in the former Pliocene seafloor.
It is estimated that about one-fifth of all the water that runs off Earth’s surface is carried by the Amazon.The flood-stage discharge at the river’s mouth is four times that of the Congo and more than 10 times the amount carried by the Mississippi River.These measurements infer that the Amazon may be recognized as the world’s longest river, supplanting the Nile.However, a river like the Amazon has a highly complex and variable streambed—made more so by seasonal climatic factors—which complicates the process of obtaining an accurate measurement.C., employed GPS gear to explore the various Andean rivers that flow into the Amazon.
Using the definition of the river’s source as being the farthest point from which water could flow into the ocean and where that water flows year-round (thereby eliminating those rivers that freeze in winter), he concluded that the source was Carruhasanta Creek on Mount Mismi.
Significant mineral discoveries have brought further influxes of population.
The Francisco de Orellana, who gave the river its name after reporting pitched battles with tribes of female warriors, whom he likened to the Amazons of Greek mythology.
Its westernmost source is high in the Andes Mountains, within 100 miles (160 km) of the Pacific Ocean, and its mouth is in the Atlantic Ocean, on the northeastern coast of Brazil.
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.
Although the name Amazon is conventionally employed for the entire river, in Peruvian and Brazilian nomenclature it properly is applied only to sections of it.