The ash from the recent eruptions of the Puyehue-Cordon Caulle in Chile has disrupted airplane schedules, even circling the globe a second time to cause more delays recently. A Michigan Tech researcher and his graduate students are studying how these volcanoes erupt and what their relation is to earthquakes. They hope to resolve much bigger issues than airplane inconveniences.
Assistant Professor Greg Waite (GMES) is focusing on “mini-earthquakes” within or beneath the troublesome Villarrica volcano. These earthquakes reveal details about the shape of the conduit and dynamics of the magmatic system.
“The seismic data suggest the conduit becomes a planar dike at a relatively shallow depth,” he says. Graduate student Josh Richardson (GMES) has studied those “spaghetti splatters”: the mini-earthquakes at Villarrica. “He recorded some 19,000 mini-quakes over the course of about a week on a recent field trip,” Waite says. These events are very subtle and cannot be simply identified without careful analysis. “We think they are from the small expansions and contractions in the conduit.”
Waite and his students’ conduit-model work has produced another interesting result at Fuego volcano in Guatemala. Recent PhD graduate John Lyons (GMES) discovered that, instead of the magma simply moving vertically up the conduit from a deeper magma chamber, there is a kink–an “elbow in the conduit, a corner in the geometry”–a couple hundred meters below the surface.
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