Prelims ask
Source range, direction, mouth, discharge rank, no classic delta.
South America
Amazon
Greatest discharge — about a fifth of all river water reaching the oceans. Length rival of the Nile; do not insist it is shorter if the question only says ‘longest’.
- Source
- Andes of southern Peru. Exam convention: Apurímac from Nevado Mismi. Some length surveys start at the Mantaro.
- Countries
- Main stem: Peru and Brazil, touching the Colombia border. Basin: Brazil, Peru, Bolivia, Colombia, Ecuador, Venezuela, Guyana, Suriname and French Guiana.
- Direction
- East.
- Mouth
- Atlantic Ocean.
- Length
- About 6,400 km.
- Major tributaries
- Madeira, Negro, Japurá, Tapajós, Xingu, Purus, Ucayali.
- Delta or estuary
- Broad estuary, not a classic protruding delta. A freshwater plume and a submarine canyon carry the load. The tidal bore is the pororoca.
- Basin
- Largest drainage basin. The basin straddles the equator; the main stem lies mostly just south of it.
- One exam fact
- Andean source, Brazilian lowland course, Atlantic mouth. East-flowing because the Andes stand on the west coast.
Mains use
Best example of a cordillera on the west coast forcing the great river to cross the continent eastward.