An international team of researchers has discovered a previously unknown trigger of volcanic eruptions -- a finding that could give scientists a leg up on predicting blow-ups and saving lives.
"Understanding the triggers for volcanic eruptions is vital for forecasting efforts, hazard assessment and risk mitigation," Dr. Janine Kavanagh, a volcanologist at the University of Liverpool in England and the leader of the team, said in a written statement. "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."
For their research, the scientists built a volcano model using a tank filled with jelly. They injected colored water into the tank to mimic ascending magma and then observed how the materials behaved using a high-speed camera and synchronized laser.
(Story continues below.)
Video of the experimental model showing the colored water as ascending "magma" in the tank of jelly. (Credit: Janine Kavanagh/University of Liverpool)
What happened? The researchers noticed a surprising drop in pressure when the ascending "magma" stalled to spread out horizontally along its journey to the surface of the tank -- geologists call this horizontal formation a "sill."
It turns out that the drop in pressure can cause the magma to behave like a buoyant foam, since magma often has gas dissolved in it. And that's when the drama begins.
“A pressure drop can drive the release of dissolved gases, potentially causing the magma to explode and erupt,” Prof. Sandy Cruden, professor of tectonics and geodynamics at Monash University in Australia and another member of the team, said in the written statement. “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.”
But the million-dollar question remains: Does this new finding point to a reliable way to predict potentially dangerous volcanic eruptions? Possibly. A horizontal sill and rapid pressure drop could serve as a warning that an eruption is on its way.
"It is very difficult to predict volcanic eruptions," Kavanagh told The Huffington Post in an email. "The accuracy of the ‘prediction’ often depends on the availability of data (e.g. how well equipped a volcano observatory is) but increasingly also on the interpretation of any available satellite data. Our results will help inform the interpretation of the satellite data; helping to identify if magma is moving, where it is going and potentially if it might erupt."
The research was published online in the journal Earth and Planetary Science Letters on April 21, 2015.