When molten rock meets water, things can get a little . . . explosive. In 2010, when Iceland's Eyjafjallajökull (say that five times fast) erupted, the ice covering the volcano created a devastating ash cloud, grounding European air traffic for days.
For now, the phenomenon is poorly understood: When volcanic eruptions push molten magma up to the surface (at which point we start calling it lava), the presence of water doesn't always cause fireworks. A 2014 eruption in Iceland spewed record-breaking quantities of lava – and occurred in an area surrounded by glaciers and groundwater – but produced no water-based explosion, and no resulting ash column.
Understanding how and why these so-called phreatomagmatic eruptions occur could help protect areas where ice and fire frequently intertwine. To puzzle out the variables that turn fire and water into explosive ash clouds, scientists need to recreate the interaction in controlled lab experiments.
And that means making their own lava.
A new facility at the University at Buffalo will focus on taking these experiments out of the lab and into the real world. Ingo Sonder, a research scientist at UB’s Center for GeoHazards Studies, will oversee experiments using gallons of artificially created lava flow – artificial systems much larger than anything ever studied, actual volcanoes notwithstanding. While working at the Universität Würzburg in Germany, Sonder and his colleagues conducted similar experiments using just "a coffee cup" of lava at a time.
"They created this explosive system in the laboratory for the first time." Sonder said. "And what we know today from those experiments is quite a bit, the sequencing of this explosion is in principle understood."
But scientists still aren't sure how to start an explosion: In the lab, mixing water and lava isn't enough. You need to trigger the system with an air gun to make it go boom. Otherwise, the water just slowly evaporates. That makes sense, given how many watery volcanoes fail to produce these violent reactions. But figuring out what makes the exceptions unique is a bit tricky.
"Scientists don't want to go firing air guns at volcanoes," Sonder joked. So he's hoping that scaling up the experiments will help his team puzzle out the natural triggers behind explosive interactions like the one seen in 2010. If the trigger was less mysterious, geologists might be able to warn residents near volcanoes primed to have these kinds of explosions – or reassure those living near ice-capped volcanoes that were (relatively) safe.
The research might also have applications in certain industrial settings – anywhere you might have molten metal coming into close contact with water, where these kinds of explosions are also a concern.
For now, Sonder and his team are working on perfecting their lava production process. It's a real doozy:
The put 10 gallons of basaltic rock, taken from the chilled remains of natural lava flows, into a high-powered induction furnace. After heating it for several hours – stirring occasionally with a steel rod – they pour the 2,500 degrees Fahrenheit brew out into metal boxes designed to mimic the underground channels through which magma flows. Then they use a remote-controlled system of tiny tubes to inject the melt with water while they scurry to safety. This injection system keeps the liquid from instantly, harmlessly sizzling off of the molten surface, instead allowing it to interact with the rock – for better or for worse.
The melt takes about four hours to make, and is only usable for around five minutes.
Once the facility is efficient at eliciting these unusual eruptions, Sonder and his team will try to single out the variables that make them possible – and figure out how they might be produced by natural conditions out in the real world. One day, they hope that their faux-magma set-up will make the Center for GeoHazards Studies a destination for eruption enthusiasts around the world. In setting up experimental conditions for one very weird kind of volcanic eruption, Sonder said, his team is creating the perfect facility for studying any sort of magma-namous behavior.