Professor of Earth Sciences, University of Auckland
The eruption is akin to a weapons-grade chemical explosion, and there could be several weeks or even years of major volcanic unrest to follow.
The Kingdom of Tonga doesn’t often attract global attention, but a violent eruption of an underwater volcano on January 15 has spread shock waves, quite literally, around half the world.
The volcano is usually not much to look at. It consists of two small uninhabited islands, Hunga-Ha’apai and Hunga-Tonga, poking about 100m above sea level 65km north of Tonga’s capital Nuku‘alofa. But hiding below the waves is a massive volcano, around 1800m high and 20km wide.
A massive underwater volcano lies next to the Hunga-Ha’apai and Hunga-Tonga islands. Author provided
The Hunga-Tonga-Hunga-Ha’apai volcano has erupted regularly over the past few decades. During events in 2009 and 2014/15 hot jets of magma and steam exploded through the waves. But these eruptions were small, dwarfed in scale by the January 2022 events.
Our research into these earlier eruptions suggests this is one of the massive explosions the volcano is capable of producing roughly every thousand years.[…]