Nature
PUBLISHED
The longest river in the world is the Nile, right? Well, maybe. Maybe not, though. The question of Earth’s longest river sounds like some simple trivia that scientists should have sorted out centuries ago. However, you might be surprised to hear how much controversy and contention surrounds the geographical record-holder.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.Guinness World Records, as well as most English-speaking sources, claim that the River Nile is the world’s longest river, stretching 6,695 kilometers (4,160 miles) from east central Africa towards Egypt’s Mediterranean coast.
The Amazon River is typically listed as the second-longest, flowing for 6,400 kilometers (3,977 miles) from the Andes through the intense rainforests of South America. It’s undoubtedly the largest river by volume of water flow – and some contend it has been unfairly jilted as the world’s longest river.
If you take a look at some Brazilian sources, you’ll find that they argue the Amazon is the river that holds record-breaking lengths, claiming that it actually measures 6,992 kilometers (4,344 miles).
This isn’t just patriotic grappling between Brazil and Egypt, although you can bet that does play a role. In recent years, several scientists (mainly from Brazil, funnily enough) have contended that scientific evidence backs up the claim that the Amazon is Earth’s supreme river.
It all depends on where you start measuring the river from, which is easier said than done. When does a trickle of water become a stream? What if a river is fed by several streams? Do you count the furthest stream from the river's mouth, even if it's a mere dribble? These are, in simple terms, some of the many questions that researchers have to grapple with.
Case in point: the source of the River Nile has been a longstanding mystery. Lake Victoria, Africa's largest lake by area, is often credited as the source of the Nile. However, this great lake is fed by other rivers, including the Kagera River, which stems from the Ruwenzori Mountains. All in all, it’s a lot more complex than it first appears.
Likewise, researchers and explorers have long sought after the source of the Amazon River. It originates somewhere in the Peruvian Andes, but it’s difficult to pinpoint where exactly.
In 2007, Brazilian scientists embarked on a 14-day expedition along the Amazon’s course to accurately measure its length. Tracking it back to a snow-capped mountain in southern Peru, they claim that the Amazon measured 6,800 kilometers (4,225 miles) in length, making it longer than the Nile.
"Today, we can consider the Amazon the longest river in the world," Guido Gelli, study author and director of science at the Brazilian Institute of Geography and Statistics, told the media.
We could soon be greeted with more evidence on the topic. In April 2024, another team of scientists is heading back to the Peruvian Andes, hoping to solve the mystery once and for all.
“The Nile is like a worm and the Amazon is an anaconda,” Yuri Sanada, Brazilian expedition leader and film producer, told CNN last year.
“So there’s no comparison – we have the biggest river. But the longest, we will see.”
