WORLD
Tonga volcano unleashed underwater flows that reshaped the seafloor
Baku, September 9, AZERTAC
The huge eruption of Hunga Tonga-Hunga Haʻapai volcano last year triggered a powerful underwater volcanic flow that destroyed hundreds of kilometres of telecommunications cables and reshaped the seafloor, according to New Scientist.
The blast in Tonga was the most powerful eruption of the 21st century, shooting ash 57 kilometres into the sky and causing 90-metre-high tsunami waves. “It was a really exceptional event,” says Michael Clare at the National Oceanography Centre in Southampton, UK.
The atmospheric impacts of the eruption were well documented. “But something really profound had happened on the seafloor and we didn’t know what it was,” says Clare.
Soon after the explosion, Clare and his colleagues decided to investigate the eruption’s impact on the bottom of the ocean.
Volcanic eruptions release a massive amount of material into the air, such as ash and lava. Some of this material quickly falls back down and forms what is known as a pyroclastic density current. “You’ll have seen loads of videos of it – imagine big clouds of really hot rock rolling down hillsides,” says team member Isobel Yeo, also at the National Oceanography Centre.
In the case of the Hunga Tonga-Hunga Haʻapai eruption, the material plunged straight into the ocean, producing a destructive underwater density current.