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. 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. FULL REPORT