The Tongan Volcano

We have all heard about the volcano which has erupted near Tonga. HERE is a very interesting article by the geologist who has been working on the volcano for years.

The volcano has erupted repeatedly for a very long time. Before this weeks eruption it showed little above the surface - two tiny islands joined by the 2015 cone, and a couple of rocks to the south east. 

A massive underwater volcano lies next to the Hunga-Ha’apai and Hunga-Tonga islands. Author provided

The author (and others) reported on the 2014/15 eruption HERE. They were mainly concerned with how long the new island would last but they also looked at the geology of the area and they conclude that the new island marks one edge of a large submarine caldera.

And it was this caldera which produced the recent huge eruption.