Thursday, 9 January 2014 Back to News

NOC Scientists Explore World's Largest Undersea Canyon

Expedition By NOC To Map And Sample Agadir Canyon, Morocco.

'Agadir Canyon is remarkably similar in size to the Grand Canyon in Arizona, and yet until now it has barely been explored.' Dr. Russell Wynn, MAREMAP Coordinator, NOC

Agadir canyon
A joint German-British team has returned from a five-week research expedition aboard the German research vessel, Maria S Merian.

Dr. Russell Wynn, of the National Oceanography Centre, led the British contribution to the expedition, whose primary aim was to map and sample a giant submarine canyon off the coast of northwest Morocco.

Agadir Canyon is over 1000 metres deep and 450 kilometres long. It is potentially the world's largest undersea canyon. Seafloor images and sediment cores collected by the researchers led to profound new discoveries about its geology and sediment mobility.

As Dr. Wynn said: 'We discovered that this huge valley is the source for the world's largest submarine sediment flow 60,000 years ago. Up to 160 km3 of sediment was transported to the deep ocean in a single catastrophic event.'

The data collected provides evidence for powerful sediment flows, transporting gravel and sand from the onshore Atlas Mountains to deep offshore basins over three miles below the ocean surface. These flows deposited sediment over an area of the deep sea floor larger than 350,000 km2. This is the first time individual sediment flows of this scale have been tracked along their entire flow pathway.

The survey team also discovered a giant landslide south of Agadir Canyon, covering an area of the seafloor roughly the size of Hampshire (5km2). Initial data suggests that it is a relatively ancient feature. It is believed to have happened at least 130,000 years ago.

Significant biological discoveries were also made in and around the canyon. The team took samples of the first living deep-water corals to be recovered from the Altantic-Moroccan margin, for example. They were also treated to an amazing aggregation of over one hundred Loggerhead Turtles basking at the surface.

Dr. Wynn hopes that the findings of the expedition will inform future work on geological hazards and marine conservation in the region. He added: 'To be the first people to explore and map this extensive and spectacular area of seafloor is a rare privilege, especially on the doorstep of Europe.'

If you would like any more information on this expedition, please contact the National Oceanography Centre.