One of the driest places on Earth was once home to a 300-plus mile long network of rivers that carried water over a larger distance than the Colorado and the Rio Grande combined, according to new research published this week in the journal Nature Communications.
Radar images taken by a observation satellite capable of peering underneath sand revealed the ancient river network along a 320-mile stretch of the Sahara Desert, according to the Guardian and USA Today. The now-buried waterway likely formed part of the Tamanrasett River thought to have once flowed across the western part of this now inhabitable region of North Africa.
Columbia University’s Peter deMenocal, who was not involved in the research, called the river network “monumental,” telling USA Today, “We have the smoking gun that this whole region,” which currently is “without rainfall at any time during the year,” was once the home of “a large, permanent system” that would have helped plants and animals thrive along its banks.
The ancient waterways were discovered under the sands of Mauritania by Charlotte Skonieczny of the University of Lille, along with French research center IFRMER. They used one of the Japanese Advanced Land Observing Satellite remote-sensing instruments, the Phased Array type L-band Synthetic Aperture Radar (PALSAR) active microwave detector.
A great geological detective story
Skonieczny’s team believes that the river network was so big that, were it still around today, it would be 12th largest river network on Earth. The river network likely originated from sources located in the southern Atlas mountains and Hoggar highlands in modern-day Algeria, USA Today and The Guardian reported. The river network may have been active as recently as 5,000 years ago.
Images taken using the PALSAR radar revealed that the river beds line up almost perfectly with a massive underwater canyon extending from the coast of Mauritania to Algerian waters located to the east. This is the Cap Timiris Canyon, was originally mapped 12 years ago, and as Skonieczny told USA Today, she and her colleagues helped to “connect the dots” between it and the river previously identified by researchers as the Tamanrasett.
“It’s a great geological detective story,” Russell Wynn, a researcher the National Oceanography Centre in Southampton and one member of the team that created the first 3D map of the canyon, told The Guardian. “It confirms more directly what we had expected. This is more compelling evidence that in the past there was a very big river system feeding into this canyon.”
He added that the new discovery “tells us that as recently as five to six thousand years ago, the Sahara desert was a very vibrant, active river system,” and helps demonstrate just how quickly climate change can happen. “Within just a couple of thousand years, the Sahara went from being wet and humid… to something that’s arid and dry,” he told the Guardian.
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Feature Image: Thinkstock
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