Turbidity currents: The mysterious underwater avalanches reshaping Earth

Turbidity currents are cascades of sediment that tumble down Earth’s 9000 submarine canyons carrying carbon, plastics and prescription drugs into the deep sea. We’re lastly studying simply how typically these dramatic occasions happen.

Earth



24 January 2023

By Kate Ravilious

IN NOVEMBER 1929, an enormous earthquake within the Grand Banks off the south coast of Newfoundland in Canada despatched tremors so far as New York. As the ocean ground shook, an unlimited amount of sand and dirt started to fire up and circulation down a canyon, gathering momentum because it went, making a dramatic underwater avalanche. It concerned sufficient materials to make two Mount Everests and triggered a tsunami that killed greater than 25 folks.

That is the most important recognized instance of an undersea avalanche, nevertheless it wasn’t a one-off. Beneath the waves, the most important avalanches on the earth frequently happen in Earth’s coasts and oceans, carving out the deepest and longest canyons on our planet. More often than not, they occur with out anybody noticing.

For lots of of years, the one witnesses to those occasions had been fish and deep-sea creatures, which could have been carried out to sea or fed by the nutrient-rich sediments that the currents carry with them. Extra not too long ago, ruptured gasoline pipelines and damaged communication cables had been proof that one thing excessive was happening. Over the previous few years, nevertheless, issues have began to alter.

Now, because of a sequence of experiments and a little bit of luck, we now have captured these Earth-carving occasions in motion. It seems the mazes of underwater canyons, lots of which had been lengthy considered geologically inactive, are something however. Armed with new knowledge, researchers have begun to piece collectively a greater image of what submarine avalanches are like, how they form Earth and their very important function in locking away the carbon warming our world.

The deepest and longest canyon techniques …