Are scientists finally close to realising what triggers volcanic eruptions?

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

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The Independent Online

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.”