Thursday, July 07, 2005
Predicting volcano eruptions?
Glen Mattioli is one of the few people who embraces them. Then again, not everyone’s job takes them to the Caribbean.
Mattioli, an associate professor in the Department of Geosciences at the University of Arkansas, and a team of researchers have been trekking regularly to the island of Montserrat since 1995 to examine Soufriere Hills volcano. "We hope to understand in a physical way how these volcanos work, then to use that information to predict eruptions," Mattioli said. "We’re monitoring the volcano and trying to tie our findings to properties we understand."
Soufriere Hills has been in the throes of a prolonged eruption since the researchers began studying it. The 10-year flare-up has led to the emigration of half of Montserrat’s 11,000 inhabitants, stymied the tourism industry and submerged the airport in a pyroclastic flow.
The island now is a living observatory for scientists dedicated to learning how to assess hazards and forecast volcanic activity.
Nearly 100 scientists will gather in Montserrat the third week of July to mark the anniversary of the volcano’s latest active period with "Soufriere Hills — Ten Years On."
Mattioli will deliver the keynote address.
His inquires have been conducted with Barry Voight, a geology and civil engineer professor at Penn State University; and Peter Malan, a seismology professor at Duke University.
Also assisting has been UA graduate student Liz Van-BosKirk; UA math graduate Neil Jones; undergraduates John Micshler of Augustana College and Jonathan McBee of Wheaton College in Massachusetts; Eylon Shaler, research professor of seismology at Duke University; and Brian Schleigh and Dr. Mike Acierno of the Carnegie Institute, who provided technical support.
The team also has added Cornell University professor Larry Brown, a reflection seismologist and the head of the Institute for the Study of the Continents.
Past work on the island has included the National Science Foundation-supported CALIPSO (Caribbean Andesitic Lava Island Precision Seismo-geodetic Observatory) project. The program in which four high-sensitivity stations were installed around the volcano to measure ground deformation and record detailed measurements of volcanic activity.
Through past efforts, researchers have concluded pyroclastic flows can incite small tsunami waves. They also located several pressure points at depths that appear to be active at different times.
In their latest proposal, they hope to learn the strength of the earth’s crust and its rigidity and how it transforms during eruptions.
The new experiment — titled SEA-CALIPSO (for Seismic Experiment with Air-gun source) — will use air guns and a string of sensors off the back of a research ship combined with sensors on land in an attempt to image Soufriere Hills’ magma chamber.
The air guns will create seismic waves that will reverberate through the earth. As the waves propagate, a certain percentage of the energy created is reflected and can be measured by the sensors. The direction of that energy is related to the properties of the material the waves pass through, and based on the direction, scientists can determine if the material is gas, liquid or a combination of liquids and solids.
Researchers also can use the speed of the waves to determine information about temperatures, which can help pinpoint whether the material in the magma chamber is liquid, solid, gas or a combination of the three.
They will chart the speed and direction of the various waves to get an image of the shape and contents of any underground chambers.
SEA-CALIPSO was scheduled for last May, but the team postponed the experiment after encountering some barriers.
Some concerns have been voiced regarding the environmental impact the seismic waves will have on marine life in the area.
Another hindrance was the boat they intend to use is a British research vessel primarily stationed in Antarctica. Its crew was unable to make the journey in May. "Everyone’s pretty excited about that experiment," Mattioli said. "We were really disappointed it didn’t go."
For now, the team’s main goal is to publicize their current findings along with their future goals in hopes of garnering more funding from the science foundation or other sources.