The Black Sea undersea river is a current of particularly saline water flowing through the

Bosphorus Strait The Bosporus Strait (; grc, Βόσπορος ; tr, İstanbul Boğazı 'Istanbul strait', colloquially ''Boğaz'') or Bosphorus Strait is a natural strait and an internationally significant waterway located in Istanbul in northwestern T ...

and along the

seabed The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'. The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...

of the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

. The discovery of the river, announced on 1 August 2010, was made by scientists at the

University of Leeds , mottoeng = And knowledge will be increased , established = 1831 – Leeds School of Medicine1874 – Yorkshire College of Science1884 - Yorkshire College1887 – affiliated to the federal Victoria University1904 – University of Leeds , ...

, and is the first of its kind in the world. The undersea river stems from salty water spilling through the Bosphorus Strait from the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

into the

, where the water has a lower salt content. Scientists have previously discovered channels running along ocean floors, based on

sonar Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigation, navigate, measure distances (ranging), communicate with or detect o ...

scanning. One of the largest of these runs from the mouth of the

Amazon River The Amazon River (, ; es, Río Amazonas, pt, Rio Amazonas) in South America is the largest river by discharge volume of water in the world, and the disputed longest river system in the world in comparison to the Nile. The headwaters of t ...

into the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

. Though it was suspected that these channels might function as rivers, it was only with the discovery of the Black Sea river that this suspicion was confirmed. Because of the power and unpredictability of these streams, they have been difficult to explore directly. A team of scientists headed by Jeff Peakall and Daniel Parsons of the University of Leeds collaborated with scientists from the

University of Southampton , mottoeng = The Heights Yield to Endeavour , type = Public research university , established = 1862 – Hartley Institution1902 – Hartley University College1913 – Southampton University Coll ...

Memorial University of Newfoundland Memorial University of Newfoundland, also known as Memorial University or MUN (), is a public university in the province of Newfoundland and Labrador, based in St. John's, with satellite campuses in Corner Brook, elsewhere in Newfoundland and ...

, and the

Turkish Turkish may refer to: *a Turkic language spoken by the Turks * of or about Turkey ** Turkish language *** Turkish alphabet ** Turkish people, a Turkic ethnic group and nation *** Turkish citizen, a citizen of Turkey *** Turkish communities and mi ...

Institute of Marine Sciences The Institute of Marine Sciences (IMS) is a Turkish facility that focuses on marine science-related education and research. IMS was founded in 1975 on the Erdemli Campus at METU (Middle East Technical University) in Erdemli / Mersin. Institute's c ...

. The team used the

Natural Environment Research Council The Natural Environment Research Council (NERC) is a British research council that supports research, training and knowledge transfer activities in the environmental sciences. History NERC began in 1965 when several environmental (mainly geogr ...

's Autosub3 – a 7-metre torpedo-shaped

autonomous underwater vehicle An autonomous underwater vehicle (AUV) is a robot that travels underwater without requiring input from an operator. AUVs constitute part of a larger group of undersea systems known as unmanned underwater vehicles, a classification that includes ...

– to get as close to the current as possible. The river was found to be long, up to deep and wide. Though smaller than the Amazon channel, the undersea river still carried ten times more water than the

Rhine ), Surselva, Graubünden, Switzerland , source1_coordinates= , source1_elevation = , source2 = Rein Posteriur/Hinterrhein , source2_location = Paradies Glacier, Graubünden, Switzerland , source2_coordinates= , so ...

. It flows at a speed of , with passing through per second. Had it been a surface river it would have ranked as the sixth largest river in the world. The river was found to contain features typical of surface rivers, such as river banks,

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

waterfall A waterfall is a point in a river or stream where water flows over a vertical drop or a series of steep drops. Waterfalls also occur where meltwater drops over the edge of a tabular iceberg or ice shelf. Waterfalls can be formed in several wa ...

s and

rapid Rapids are sections of a river where the river bed has a relatively steep gradient, causing an increase in water velocity and turbulence. Rapids are hydrological features between a ''run'' (a smoothly flowing part of a stream) and a ''cascade''. ...

s. One major difference was that the underwater river, when rounding a bend, moved in currents spinning in the opposite direction from those on land. The river works as a

density current In fluid dynamics, a gravity current or density current is a primarily horizontal flow in a gravitational field that is driven by a density difference in a fluid or fluids and is constrained to flow horizontally by, for instance, a ceiling. Typica ...

, because it carries

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...

s along the sea floor and has a higher

salinity Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...

than the surrounding water.

References

{{reflist Black Sea Physical oceanography Coastal and oceanic landforms Bosphorus

See also

References