Supervolcanoes Erupt Due to a Different Process Than Standard Volcanoes

Supervolcanos are not usual volcanos. By effectively "exploding" as opposed to erupting, they leave a giant hole in the Earth's crust instead of a volcanic cone – a caldera, which can be up to one hundred kilometres in diameter. On average, supervolcanos are active more rarely than once every 100,000 years; since records began, none has been active. Consequently, researchers can only gain a vague idea of these events based on the ash and rock layers that have survived.

A team of researchers headed by ETH-Zurich professor Carmen Sanchez-Valle has now identified a trigger for supereruptions by determining the density of supervolcanic magma, using an X-ray beam at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. This enabled the scientists to demonstrate that the overpressure generated by density differences in the magma chamber alone can trigger a supereruption. The magma chamber is located in the Earth's crust beneath the volcano. The new findings could help us to understand "sleeping" supervolcanos better, including how quickly their magma can penetrate the Earth's crust and reach the surface.

link.