Friday, May 17, 2024

Largest Underwater Sediment Avalanche Found


Scientists working with the Natural Environment Research Council (NERC) and the National Oceanography Centre (NOC) were able to recover data that showed the largest recorded underwater seabed sediment avalanche ever recorded.

The event occurred in 2020 in the Congo Canyon, a massive undersea valley that leads away from the mouth of the Congo River in Africa. Researchers had already lined the canyon with sensors when in January, a huge avalanche moving at more than 8m/26ft per second broke 11 sensors free. The scientists finally managed to retrieve nine of these sensors — which floated to the surface — and extracted their valuable data.

The sensor data revealed that the underwater avalanche, called “turbidity currents,” traveled a massive 1,100km/683.5 miles from the mouth of the Congo River estuary and sediment reached a depth of 4,500m/14,764ft.

Peter Talling, the study’s lead investigator and professor in submarine geohazards at Durham University, stated:

“The odds of retrieving football-sized sensors were tiny, as they drifted in different directions, dragged by currents across hundreds of kilometers of ocean. Rescuing those buoys seemed entirely improbable…But, thanks to swift and flexible action by NERC, the National Marine Facilities at the National Oceanography Centre, French colleagues at IFREMER and senior colleagues in Hull and Durham Universities, together with several passing vessels, we achieved one of the most remarkable bits of fied science in the ocean I’m ever likely to see.”

Commenting on the effort that went into recovering the sensors, NERC’s Head of Marine Planning Natalie Powney stated:

“Making this project possible required a huge team effort from everyone, including staff from NERC and the National Marine Facilities team at the National Oceanography Centre. Within just 48 hours, NERC had assessed and approved the rescue attempt…Funding was provided through our Discovery Science Portfolio, which encourages curiosity-driven, adventurous science. The research is hugely significant and identified a link between major river floods, spring tides and powerful turbidity currents.”

You can find the original research paper here.

Sam Helmy
Sam Helmy
Sam Helmy is a TDI/SDI Instructor Trainer, and PADI Staff and Trimix Instructor. Diving for 28 years, a dive pro for 14, I have traveled extensively chasing my passion for diving. I am passionate about everything diving, with a keen interest in exploration, Sharks and big stuff, Photography and Decompression theory. Diving is definitely the one and only passion that has stayed with me my whole life! Sam is a Staff Writer for