Are scientists finally close to realising what triggers volcanic eruptions?

Breakthrough in identifying source of eruptions made in experiment with jelly and lasers

An international team of researchers have made an important step towards understanding how volcanic eruptions happen, after identifying a previously unrecognised potential trigger.

The team used jelly and lasers in an experiment to model how magma ascends from great depths to the surface through a series of connected fractures.

A tank was filled with jelly as coloured water was injected to mimic ascending magma, while a high-speed camera and a synchronised laser were used to observe.

Professor Sandy Cruden, from the School of Earth, Atmosphere and Environment at Monash University, said: “It was at this point that we discovered a significant and previously unknown drop in pressure when the ascending vertical dyke stalled to form a horizontal sill.

“Sills often form in nature as part of a developing volcanic plumbing system, and a pressure drop can drive the release of dissolved gasses, potentially causing the magma to explode and erupt,” he said.

“It’s similar to removing a cap from a bottle of shaken fizzy drink – the pressure drop causes bubbles to form and the associated increase in volume results in a fountain of foam erupting from the bottle.”

Dr Janine Kavanagh, from the University of Liverpool’s School of Environmental Sciences and lead author, said: “Understanding the triggers for volcanic eruptions is vital for forecasting efforts, hazard assessment and risk mitigation.

“With more than 600 million people worldwide living near a volcano at risk of eruptive activity, it is more important than ever that our understanding of these complex systems and their triggering mechanisms is improved.

“There is also a strong economic incentive to understand the causes of volcanic activity – as demonstrated in 2010 by the eruption of Eyjafjallajökull, Iceland, which caused air-traffic disruption across Europe for more than one month, with an estimated US$1.8 billion loss in revenue to the airline industry.”