Natural Disasters

Tonga volcanic eruption altered Pacific seafloor’s shape

Volcano’s crater is now 700 metres deeper than it was before the blast

By DTE Staff
Published: Wednesday 23 November 2022

On January 15, 2022, Hunga Tonga-Hunga Ha’apai volcano unleashed a tremendous blast. A blast which was hundreds of times stronger than the Hiroshima nuclear explosion.

The Tonga volcano eruption was so loud that it was heard in Alaska, which is about 6000 miles away and the tsunami that followed devastated the country with waves up to 15 meters high, causing an estimated $90.4 million worth of damage. But the impact of the massive eruption was not fully comprehended.

A new report now reveals that the deadly volcanic eruption near Tonga was the largest and strangest ever recorded with any modern equipment. The group of scientists from New Zealand and the UK performed a detailed mapping of the area around the Pacific volcano to reach new findings.

The report shows that the seafloor was scoured and sculpted by violent debris flows up to a distance of over 80km, essentially reshaping the Pacific seafloor. When the underwater mountain erupted, it sent ash and water vapour which went up to 57 Km into the skyspace.

The first recorded eruption to do so. The gathered data also indicates that around 10 cubic km of debris was displaced during the catastrophic event. This volume is equivalent to 4,000 Egyptian pyramids. Two-thirds of that was the ash and rock ejected through the volcano’s opening and a large proportion of that just went straight up into the stratosphere.

A third of the material scraped off the top and the sides of Hunga-Tonga as debris fell back to the ocean bottom. The research team also discovered that the volcano’s crater is now 700 metres deeper than it was before the blast.

The new study gave a detailed idea to the scientific world about underwater volcanic eruptions. All the results from the new report will ultimately feed into hazard mitigation, to prepare Pacific nations situated close to the volcanic zone.

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