Since the discovery of the Amazon by the Western world, a debate has raged over which river is longer — the Nile or the Amazon. The question is more complicated than you might think. Here's how the two compare.
How to Measure the Length of a River
There are some complications that come with trying to measure something that spans an entire continent. The simplest way to measure a river is to identify its source, which is the point where the river begins, and the mouth, which is where the river ends, often by flowing into an ocean.
While this may seem straightforward enough, there are variables. For example, does a source count if it doesn’t flow year-round? At what point does one river become a part of another river? The Mississippi is a prominent river in North America, but if you count the Missouri as a tributary of the Mississippi, it becomes three times longer.
Finding the source and the mouth is not the end of the issue, either. Rivers flow through all types of terrain, so you can’t just get out a map and a ruler to find the distance. For an accurate measurement, scientists have to physically measure how many miles the river crosses — which is not an easy feat.
Africa’s longest river has been considered the biggest river in the world since ancient times. The river famously nurtured life in the Nile Delta and helped some of the most powerful civilizations of early society. Most notable were the Egyptians, whose pharaohs oversaw the construction of the pyramids of Giza, which still stand today.
The Nile has two major tributaries — the White Nile and the Blue Nile. The White Nile is the longest of the two and originates in Burundi. The Nile crosses through 11 countries on its way to the Mediterranean Sea, with a total estimated length of 4,160 miles — making it the longest river in the world.
The longest river in South America originates on the Eastern side of the Andes and ends when it enters the Atlantic Ocean in Brazil. The exact point of its origin is disputed, but for most of the last century, it was considered to be the Apurimac region of Peru. This measurement makes the Amazon River 4,050 miles long, just shy of the Nile’s length.
However, a recent expedition by a team of Brazilian researchers found a new source for the river. Their new estimation places the river at 4,225 miles long – 65 miles longer than the Nile. While these results have been embraced by the Brazilian government, who proudly proclaim the Amazon the world’s longest river, the results are unpublished and have not been embraced by the greater scientific community.
Which One Is Longer?
While there may not be a definitive answer to that question at this point in time — and there may never be — it is safe to say that the Nile is still considered the longest. However, the Amazon does unquestionably take home one title — the largest river by volume. The Amazon river discharges four times more water than any other river on the planet. So, while it may still take time to figure out which river is the longest, we already know which one is the largest.