Top 10 Longest Rivers In The World

Last updated on April 12th, 2022

2. The Amazon – the world’s second longest river

The most popular river in the world is the Amazon River. The river is popular for a variety of reasons; including its impressive length, flow rate and amount of life it supports. Recently, however, the Amazon river has been on the spotlight because of the destruction of the Amazon Forest, which supplies the water flowing in the Amazon River. 

1. The Amazon River discharges 6,591 cubic kilometer of fresh water into the ocean every year. This is equivalent to a discharge of 209,000 cubic meters per second. This accounts for over 20% of global discharge from rivers into oceans.

2. In terms of flow rate, the Amazon River is larger than the combined flow of the next 7 largest rivers in the world.

3. The Amazon River has a rich ecosystem that supports over 2,700 fish species. This is higher than the number of fish species found in the Mekong and Congo rivers combined. Unfortunately, 1,700 of these species are endemic (native and restricted to a certain place).

4. An entire coral reef system thrives in the Amazon River Delta. The reef is 1,000 km long, covers a total area of 9,500 square kilometers and hosts an impressive collection of exotic marine life. Recently, scientists discovered giant sponges that were larger than small elephants.

The Amazon river with tributaries
The Amazon River highlighted on the map of the Amazon River drainage basin. World’s second longest river. Image credit – Kmusser/CC BY-SA 3.0

5. The Amazon River has 1,100 tributaries. Some of these tributaries are over 1,497 km long. These tributaries are from Peru, Bolivia, Ecuador, Colombia, Venezuela and Brazil.

6. The width of the river varies with the season. During the wet rainy season, the width of the river averages 2 to 6 miles. During the dry season, however, the width of the river can swell up to 30 miles.

7. There are 3 major cities around the Amazon River Basin. The first is Belem in Brazil, where the river empties into the Atlantic. Belem is home to over 1.3 million people. The city of Iquatos in Peru is the gateway to the villages located in the Northern Amazon. Santarem, Brazil sits on the junction of the Tapajos River and the Amazon River.

Traditional house on the Amazon river
Traditional house on the Amazon river in Iquitos, Loreto, Peru. Photo © Daniel San Martin |

8. Martin Strel, a Slovenian swimmer holds the world record for swimming the entire length of the Amazon River. He covered the entire length in just 67 days, proving that the mightiest river in the world can also be conquered.

9. The Amazon River used to flow into the Pacific up until about 15 million years ago, when the Andes Mountains were formed. The Andes Mountains are now considered the source of the Amazon River, which flows in the opposite direction into the Atlantic.

Amazon river on map


10. The depth of the Amazon fluctuates with the season by as much as 15 meters in some sections. The deepest point in the Amazon River is over 100 meters, but the average depth is 20-50 meters.

11. It is possible to surf on the Amazon River twice a year when the sun, moon and earth are aligned (equinox). This usually creates a tidal wave that travels up to 800 km upstream.

12. The Amazon River is home to the largest species of river dolphin (Inia geoffrensis). The dolphin can grow more than 8 feet long. Its color changes with age from gray to pink to white. 

Amazon River Pink Dolphin.
Amazon River Dolphin. Photo © Anna Artamonova |

13. The Amazon River Delta measures one million square miles and is considered one of the largest river delta in the world. It is a muddy patch of salt and fresh water.

14. The Amazon River affects sea level when it empties water into the Atlantic. Most of this water is carried by current into the Caribbean sea, raising the level of the Caribbean Sea.

15. The Amazon was named after the Greek mythology “Amazon female warriors”. This is after the European Explorer who named the river saw women fighting alongside their male counterparts in the Amazon.

16. The Amazon has been confirmed to have an underground version of itself flowing at a depth of 4 km, but the flow is slow and river width is wider.

17. The tributaries feeding the Amazon River have more than 100 dams with many others still under construction.

The northeast coast of Brazil and the Amazon River.
The northeast coast of Brazil and the Amazon River. Altocumulus clouds blanket the northeast coast of Brazil where the Amazon River flows into the Atlantic Ocean. Image credit – NASA Johnson

18. No bridge has ever been built across the river, which means that people who live on the banks can only cross using boats.

19. The Amazon River Ecosystem is dependent on the Sahara desert. Winds usually blow sand and dust from the Sahara, carrying phosphorous and other important nutrients that support life in the Amazon.

20. About forty percent of fresh water in South America end up in the Amazon River and get emptied into the Atlantic Ocean. This is because most tributaries are spread out throughout South America.

The Amazon – quick facts and statistics

NameThe Amazon
SourceRío Apurimac, Mismi Peak (location: Arequipa Region, Peru)
MouthAtlantic Ocean (location: Brazil)
Length6650 km
Widthmaximum 100 km (62 mi)
Depthmaximum 100 m (330 ft)
CountriesPeru, Colombia, Brazil
Major citiesIquitos (Peru); Leticia (Colombia);
Tabatinga (Brazil); Tefé (Brazil);
Itacoatiara (Brazil) Parintins (Brazil);
Óbidos (Brazil); Santarém (Brazil);
Almeirim (Brazil); Macapá (Brazil);
Manaus (Brazil)
Basin size7,000,000 square kilometres (2,702,715 sq mi)
Direction of flowwest to east
Did you know?1. The Amazon River has more than 1,100 tributaries.

2. The Amazon River is home to the piranha .

3. The Amazon River is also home to one of the world's largest snakes - the anaconda.

4. The Amazon's flow is over 4 times that of the Congo River, the world's second largest river. And it is 10 times that of the Mississippi, the largest river on the North American Continent.

5. Its high to low-flow ratio is about 5 to 1 which indicates an uncommonly small difference between flood and low flows.

6. The Amazon is one of the cleanest rivers on earth; its chemical purity is near that of distilled water better than that of most public water supplies in the United States.

7. Besides being one of the longest rivers in the world, it also happens to be the widest.
Table last updatedDecember 6, 2021

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