The Amazon: Earth’s Mightiest River, Andes to Atlantic

The Amazon River is uncontested:

• Length: ~6,400 km (3,977 mi) — 2nd longest (after Nile) by some measures; longest by discharge.
• Discharge: 209,000 m³/s (avg) — 20% of all river water entering oceans. More than next 7 rivers combined.
• Basin: 7,050,000 km² — 40% of South America.
• Source: Nevado Mismi (Apurímac headwater), Peruvian Andes (5,597 m).
• Course: East across Peru, Colombia, Brazil. Meets Atlantic at Marajó Island (world’s largest fluvial island).
• Tributaries: 1,100+ named. Rio Negro, Madeira, Tapajós, Xingu, Purus, Japurá — each a major river.

Why "Mightiest"? Not just volume. Sediment load (1.2 Gt/yr) builds the Atlantic continental shelf. Biodiversity: 3,000+ fish species (new ones yearly). Climate engine: Evapotranspiration drives "flying rivers" rain across continent.

No other river shapes a continent like the Amazon.