The Mighty Amazon

Laguna Lauricocha: possibly the source of the Amazon

The Amazon begins high in the Peruvian Andes as a thin sheet of crystal water flowing down the side of a rock wall. By the time its journey ends in the Atlantic Ocean some 6,275 km away, it has become the world’s largest river by volume, and possibly the longest.

The serene mountain lake on the pictures, Laguna Lauricocha, is only a few km away from the source of the Amazon river. It is situated in the department of Junín in the Cordillera Huayhuash. The river Marañon feeds this lake. After Laguna Lauricocha, the Marañon flows on northwards for hundreds of kilometres through mountains and canyons, and then eastwards into the Amazon basin. There, near the jungle town Nauta, the Marañon is joined by another big river coming from the south: the Ucayali. At this point both rivers confluence and continue into Peru's eastern lowlands and Brazil under the name Amazon. The Times Atlas of the World, edition 1996, pinpoints the place near Laguna Lauricocha as the main source of the Amazon. At least that was the opinion of leading geologists in 1996...

Laguna Lauricocha

...Because recently an expedition from National Geographic came to another conclusion. A team consisting of 22 people representing the United States, Peru, Canada, Spain, and Poland, explored all five of the remote Andean rivers that combine to form the Amazon: the Apurimac, Huallaga, Mantaro, Marañon, and Urubamba-Vilcanota.

Nevado Mismi with an expedition member. This
could be the source of the Amazon as well

The team has identified the place where the Amazon begins on a slope of Nevado Mismi, a 5,597-meter mountain in southern Peru in the department Arequipa. The Nevado Mismi lies in an Andean mountain range with the name Cordillera del Chila, and is about 10 km from the small city of Chivay in the Colca canyon. The source of the Amazon can be defined as the most distant point in the drainage basin from which water runs year-around, or the furthest point from which water could possibly flow into the ocean. Nevado Mismi fits both these definitions, the expedition members conclude.

The Amazon and its sources in Peru

Confluence of the
Apacheta and Lioqueta
river near Nevado Mismi

The Urubamba river at Pongo de Mainique

The Huallaga river in Tingo María. Image © Javier Martel

The world’s largest river in watershed area, number of tributaries and volume of water discharged, the Amazon has only one rival as the world’s longest: the Nile. The major headstreams of the Amazon join near Nauta, Peru. From there the river flows generally eastward to discharge in the Atlantic Ocean. With an undetermined number of tributaries — more than 200 in Brazil — the river’s watershed includes the world’s largest and wettest tropical plain. The river ranges in width from 1.5 to 10 kilometers during the dry season to 48 kilometers or more during annual floods. No waterfalls or other obstructions are found along its course. Ships with 5-meter drafts can navigate all the way from the Atlantic Ocean to Iquitos in Peru, nearly its entire length.

Nauta: The Marañon river

Iquitos, view over the Amazon

See also: physical geography