20+ Interesting Facts About the Amazon River

1. Amazon River is the longest river in South America and the second longest in the world after the Nile. Its minimum length is 6,400 km (3,976 miles), slightly less than the Nile River (6,650 km or 4,130 miles).
2. Some Brazilian scientists argue that Amazon is the longest river based on their observations. However, USGS (United States Geological Survey) rejects these claims because of satellite mapping and maintains that Amazon is the second-longest river after the Nile. (Source)
3. Amazon river largely flows through Brazil and Peru. However, it has several tributary rivers present in other countries bordering Peru and Brazil.
4. Amazon is the largest river by volume. Its average discharge is over 200,000 m³/s, five times the second-largest river (Congo River).
5. Amazon basin covers an area of nearly 7,000,000 sq. km. It is the world’s largest drainage basin and almost twice as large as the Congo basin, the second largest drainage basin. (Source)
6. Amazon is the fifth deepest river in the world and the deepest in South America. Its maximum depth is 328 feet (100 meters).
7. Heavy seasonal rainfall forms 250,000 km² of riverine-flooded forests in the Amazon basin, the most extensive in the world. Different parts of this system receive floodwater at separate times of the season due to uneven rain distribution. These flooded forests support the growth of a high number of species. (Source) 

   

   Flooded forests in the Amazon basin are the world's most extensive

   
   
8. The initial direction of the Amazon River was from east to west. However, it changed its flow and adopted the current route from west to east 10 million years ago. Previous estimates considered the reason behind this shift was a change in the flow of thick rocks beneath South America. However, the latest computer models show it happened due to erosion and sedimentation. (Source)
9. A vast area of the Amazon basin has soil of very low fertility. However, there are hundreds of patches in this area with nutrient-rich soil, known as Amazonian Dark Earths (ADEs). This soil contains a high amount of calcium, phosphorus, and other micronutrients deficient in the remaining soil. According to a theory, indigenous people of the Amazon basin are responsible for creating this fertile soil. (Source)
10. A surprising feature of the Amazon River is the presence of a large river beneath its surface. Rio Hamza, discovered in 2011, is more than 4 km underground. Both these rivers are 6,000 km long. However, the width of the Hamza River is from 200 km to 400 km, compared to the 1 km to 100 km of the Amazon River. The direction of both rivers is the same, but Amazon flows faster than Rio Hamza. (Source)
11. In 2016, scientists discovered a 600-miles long coral reef system below the Amazon River. Corals usually grow in sunlit, clear, and saltwater, but the water at the mouth of the Amazon is one of the muddiest and unfavorable for coral reefs. These reefs contain several species of sponges, fish, stars, lobsters, and other marine life. (Source)
12. According to estimates, the Amazon River is responsible for transporting 20% of the freshwater from the earth’s surface to the ocean.
13. A Spanish soldier was the first European to explore the Amazon, who named this river after female warriors of Greek mythology (Amazons). He did that after fighting battles against the tribes of female warriors near this river.
14. A Portuguese military officer was the first European to explore the entire river in 1637. This exploration ended after two years, during which he covered more than 3,500 land and nautical miles.
15. Central Amazon Conservation Complex in Brazil is the largest protected area in the Amazon basin, covering more than 6 million hectares. It protects several endangered species, including river dolphins, electric fish, the black caiman, the Amazonian manatee, etc. (Source)
16. There are more than 8,000 insect species, 2,500 fish species, several mammals, reptiles, and other aquatic and semi-aquatic animals in the Amazon River. Famous fauna of this river includes the Amazon River dolphins (the largest river dolphin), black caimans (the largest predator in the Amazon River), giant otters (the longest weasel), green anacondas (the heaviest snake), Amazonian manatees, electric eels, and piranhas.
17. The salinity of the Caribbean Sea decreases considerably during the fall season. The Amazon River plays a vital role in this annual depression by contributing 60% of freshwater in the Caribbean Sea during this period. (Source)
18. In 1980, a Canadian family (father and two sons) started their journey by canoe from Red River (Canada) and reached the Amazon River in 23 months. During this trip, they crossed 13 countries and traveled a distance of 20,000 km. (Source)
19. Martin Strel, a Slovenian citizen, achieved the longest journey swimming (open water) by crossing the entire Amazon River (5,268 km). He completed this feat in 67 days (from February 1 to April 8, 2007). (Source)
20. More than 100 hydropower dams have been constructed in the Amazon basin, while several other projects are underway. However, the construction of numerous dams can negatively affect the Amazon basin. (Source)
21. Amazon Rainforest is the world’s largest rainforest, covering an area of 2.3 million square miles. This rainforest is present in the drainage basin of the Amazon River and its tributaries.