Unraveling the Mysteries of Underwater Avalanches and their Impact on the Seafloor

Below the ocean surface, unstoppable currents drag enormous amounts of silt towards the sea floor, which is constantly changing as a result. Other things, such as carbon, plastic and pills, also tumble into the depths. Researchers are finally getting to grips with how, and how often, these violent events play out.

In November 1929, an unprecedented earthquake off the Grand Banks of Newfoundland, a group of underwater plateaus off Canada’s east coast, shook even New York to its foundations. The shaking of the seabed caused a huge stream of sand and mud, which plunged into a ravine. At one point the current gained so much momentum that a spectacular underwater avalanche started. Rocks the size of two Mount Everests were moved, causing a tsunami that would kill twenty-five people.