Storm in ocean with big windy waves. Depositphotos.

Longest Underwater Avalanche Traveled for 1,100km at 8 Meters Per Second

Scientists from the Department of Earth Sciences at the University of Durham examined the data and found evidence of a seabed sediment avalanche that traveled up to 4,500km in depth and traveled for 1,100km.

Researchers have recovered data that had been swept away by a dramatic underwater avalanche and discovered what is now the world’s longest underwater avalanche.

Due to the avalanche, sensors used to monitor the Congo Canyon, the world’s largest underwater valley, were scattered across the Atlantic Ocean.

The lost sensors were discovered after a quick search of thousands of kilometers of the ocean.

Scientists from the Department of Earth Sciences at the University of Durham examined the data. They found evidence of a seabed sediment avalanche that traveled up to 4,500km in depth and traveled for 1,100km.

A large avalanche had swept through the Congo Canyon, a deep underground valley off the west coast of Africa that leads away from the Congo River’s mouth.

The Congo River experienced severe flooding, followed by unusually high tides, resulting in an avalanche of sand and mud equivalent to one-third of the yearly sediment produced by all rivers worldwide.

As a result of the avalanche of sediment traveling at speeds up to eight meters per second, eleven sensors used to monitor the canyon were dislodged from their moorings in January 2020.

A series of orange buoys, barely larger than a football, carried the sensors’ unique data across the surface of the Atlantic Ocean.

Despite their drifting in different directions, tugged by currents across hundreds of kilometers of ocean, there was little chance of retrieving the sensors. Rescuing those buoys seemed entirely improbable, explained professor Talling.

“But, thanks to swift and flexible action by NERC, the National Marine Facilities at the National Oceanography Centre, French colleagues at IFREMER, and colleagues, together with several passing vessels, we achieved one of the most remarkable bits of field science in the ocean I’m ever likely to see.”

Direct measurement of powerful deep-sea avalanches was considered impossible before this study.

Researchers were able to assess for the first time how major river floods connect to deep-sea flooding thanks to the rescued data, which provided direct monitoring of sediment avalanches in the Congo Canyon.

In addition to cutting two seabed telecommunications cables, the avalanche also slowed internet speeds in west, central, and southern Africa.

A study found that the pattern of seabed erosion was surprisingly patchy and localized, especially for a flow of this magnitude. It may explain why some submarine telecommunication cables were broken while others were not.

Using this information, cable companies may be able to better position cables to survive these events in the future.


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Written by Ivan Petricevic

I've been writing passionately about ancient civilizations, history, alien life, and various other subjects for more than eight years. You may have seen me appear on Discovery Channel's What On Earth series, History Channel's Ancient Aliens, and Gaia's Ancient Civilizations among others.

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