Scientists have discovered a river whose flow is 10 times mightier than the largest river in Europe on the floor of the Black Sea, proving that previously mysterious channels visible on ocean floors are in fact formed by underwater rivers.The Black Sea river, the first-ever still-flowing underground channel to be discovered, carves out channels just like a river on land, and even has rapids and waterfalls.
A group of researchers from England's University of Leeds, Canada's Memorial University and Turkey's Institute of Marine Science discovered the current when they carried out a detailed study of a puzzling 37-mile-long channel at the bottom of the Black Sea.
The existence of these underwater rivers or submarine channels has been suspected since the 1970s, when advances in sonar technology allowed scientists to produce detailed 3-D maps of the ocean floor.
Unlike ocean trenches, which are geological formations made by the movements of tectonic plates, submarine channels are created when water loaded with salt or sediment washes along and erodes the seabed. Until now, though, exactly how this dense water moves along these channels has been something of a mystery.
The scientists found that the channel is filled with fast-moving salty water spilling from the Mediterranean into the less salty Black Sea at the two bodies' meeting point: the Bosphorus Strait.
The Mediterranean-derived water flows as a result of gravity, acting on the density difference that's produced by higher concentrations of salt.
If found on land, scientists estimate it would be the world's sixth largest river, in terms of how much water is flowing through it.
