Is the Amazon River Longer Than the Nile?

There is a debate that has been going on for quite some time now: which is the world's longest river: the Amazon or the Nile? In the 20th century, consensus "granted" the title to the Nile. But now, Brazilian researchers claim the Amazon River, not the Nile, is the longest in the world. The Amazon is by far the world's largest river by debit, but the general opinion is that it is slightly shorter than Africa's Nile.

They have followed the river's source to a snow-capped mountain in southern Peru, during a 14-day expedition, lengthening the Amazon by about 176 miles (284 kilometers). In this case, the Amazon would be 65 miles (105 kilometers) longer than the Nile, as the Amazon would be 4,225 miles (6,800 kilometers) long, while the Nile has 4,160 miles (6,695 kilometers) in length.

"Today, we can consider the Amazon the longest river in the world," said study author Guido Gelli, director of science at the Brazilian Institute of Geography and Statistics, to London's Telegraph newspaper. "Determining the length of a river is tricky because scientists have to pinpoint both where the river begins and ends," Andrew Johnston, a geographer at the Smithsonian's National Air and Space Museum in Washington, D.C., told National Geographic News.

Johnston took part in 2000 in a similar research. "The mouth of the Amazon is so wide, it's hard to pick the exact spot at which to choose the end point with that kind of precision. Personally, I would want to know a little bit more about how they came to that number before I was comfortable saying, 'Yes this is longer,'" he said.

"The debate over river length is trivial, but I hope the announcement will focus international attention on the Brazilian government's efforts to build more than 60 large dams on the Amazon's major tributaries. The Amazon continues to be by far the river system which sustains the most biodiversity and which continues to maintain a natural state throughout most of its course," said Glenn Switkes, the São Paulo-based Latin America coordinator for the conservation group International Rivers Network.