Amazon Facts

Compiled from lectures by Dr. Don Klein

AMAZON BASIN: Size = 3.2M sq. mi. (about the same size as the continental U.S.)

AMAZON RIVER: Length = 3968 to 4216 miles; varies depending on geographic delimitation of the actual “mouth” (variations exist to the exact location of the mouth depending on the study).

AMAZON R.[iver]: Drains 8 countries: Brazil, Surinam, Guyana, Venezuela, Colombia, Ecuador, Peru, and Bolivia.


      80,000 plant species.

      50,000 insect species.

      50,000 miles of navigable waterways.

      15,000 individual rivers.

      5,000 tree species.

      2,000 freshwater fish (more species than the Atlantic Ocean).

      125 indigenous or native-American tribal entities.

      1 Betty (the protagonist in the presentation Piranhas to Primates).

AMAZON R. drops from 18,000 ft above sea level, 100 miles from the Pacific, to nearly sea level in 600 miles—from there it flows 3,500 miles to the Atlantic in a gradual decent of 600 feet—dropping < 2 inches for each mile it flows east to the Atlantic.

AMAZON R. drains 20% of the earth’s FLOWING fresh water (rivers; this excludes ice caps such as Greenland and the glaciers of So. America, the Arctic and Antarctic).

AMAZON R. a one day discharge is 4.5T gallons; will supply all the homes in the U.S. for > 5 months.

AMAZON R. at the mouth it deposits 1.3M tons of nutrient enriched (volcanic soil) sediment per day.

AMAZON R. a billion tons of sediment flows out of the Amazon mouth into the Atlantic each year. 

AMAZON R. sediment outflow from the Andes enriches its lower banks (called várzea) with nutrients for agriculture (this soil enrichment is deemed underutilized).

AMAZON R. has enough effluent (outflow) at the mouth to fill Lake Ontario in 3 months.

AMAZON R. the average discharge rate at the mouth is 7.1M cubic feet per second.

AMAZON R. The effluent extends 150 miles out into the Atlantic and takes up the full width of the mouth, which is ~150 miles wide.

The largest island in South America and the largest freshwater island in the world is in the mouth of the Amazon—the size of MA, CT and RI together, it is called Ilha Marajó.

World’s largest freshwater archipelago (Anavilhanas) in the Rio Negro has 300 islands.

Large ships are able to transit the Amazon from the mouth to Manaus—900 miles upriver; smaller ships (less than 300 ft long) are able to traverse the Amazon 2300 miles from the mouth to the city of Iquitos, Peru. All ships over 500 tons require 2 river pilots.

AMAZON Rain Forest soil and subsoil are naturally infertile and have been depleted of nutrients by the incessant rain and weathering that has acted on it over many millions of years.

AMAZON R. F. has more species of butterflies, half the world’s bird species, world’s largest parrots, largest rodents (125 lb. capybara), snakes (23 ft anaconda) and largest ants (>1 inch).

AMAZON R. F. has the world’s largest otter, one of the world’s largest freshwater fish (the pirarucu), the most species of bats, and the most species of monkeys (among them Betty, the red howler monkey).

AMAZON R. F. has an equatorial location and a very uniform climate (rainfall, heat and humidity) with a long geologic history of nearly 200M years.

AMAZON R. F. has the most fragile of eco-systems and may not survive the pressures ir has had to endure over the last decades, which means we need to make every attempt to ensure its survival—which is indirectly linked to our own survival (living in a temperate zone).

Google the phrase “Amazon sustainability” to see which NGOs are attempting to help in this survival process. Support the organizations that are important in rainforest survival such as the World Wildlife Fund, Survival International, the National Geography Society, The Smithsonian Institute and the Rainforest Action Network.