The mysterious underwater avalanches reshaping Earth

Turbidity currents are cascades of sediment that tumble down Earth’s 9000 submarine canyons carrying carbon, plastics and pharmaceuticals into the heavy sea. We are yet learning conscionable however often these melodramatic events occur.

Earth 24 January 2023

By Kate Ravilious

Pete Reynolds

IN NOVEMBER 1929, a immense earthquake successful the Grand Banks disconnected the southbound seashore of Newfoundland successful Canada sent tremors arsenic acold arsenic New York. As the oversea level shook, a immense quantity of soil and mud began to disturbance up and travel down a canyon, gathering momentum arsenic it went, creating a melodramatic underwater avalanche. It progressive capable worldly to marque 2 Mount Everests and triggered a tsunami that killed much than 25 people.

This is the biggest known illustration of an undersea avalanche, but it wasn’t a one-off. Beneath the waves, the largest avalanches successful the satellite regularly hap successful Earth’s coasts and oceans, carving retired the deepest and longest canyons connected our planet. Most of the time, they hap without anyone noticing.

For hundreds of years, the lone witnesses to these events were food and deep-sea creatures, which mightiness person been carried retired to oversea oregon fed by the nutrient-rich sediments that the currents transportation with them. More recently, ruptured state pipelines and breached connection cables were impervious that thing utmost was going on. Over the past fewer years, however, things person started to change.

Now, acknowledgment to a bid of experiments and a spot of luck, we person captured these Earth-carving events successful action. It turns retired the mazes of underwater canyons, galore of which were agelong thought to beryllium geologically inactive, are thing but. Armed with caller data, researchers person begun to portion unneurotic a amended representation of what submarine avalanches are like, however they signifier Earth and their captious relation successful locking distant the c warming our world.

The deepest and longest canyon systems …