Small Town News

Volcano Expert Takes Education To Ecuador

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SOCORRO - New Mexico Tech geophysics professor Dr. Jeffrey Johnson recently completed a successful month-long field course studying the Tungurahua Volcano in Ecuador.

Sixteen graduate students from 12 universities in four countries -- including three from New Mexico Tech -- spent June in Ecuador learning about volcanoes and their inner workings. Johnson led the graduate level class, Geophysics 572, along with New Mexico Tech scientists and instructors from the Institute Geofisico of the Escuela Politecnica Nacional in Ecuador.

"This was one of the best classes I've ever taken," doctoral student Hunter Knox said. "Ecuador is an excellent natural lab for teaching students about volcanoes."

The New Mexico Tech instructors included Dr. Rick Aster, geophysics professor and chair of the Earth and Environmental Science Department, geo-chemist Dr. Nelia Dunbar, geochronologist Dr. Bill Mcintosh and geophysicist Dr. Mark Murray.

The course also gave the New Mexico Tech scientists an opportunity to build relationships and expand partnerships with colleagues in Ecuador.

"It's an exciting time for science in Ecuador," Aster said. "We have all sorts of ongoing associations there. They have a great group of people and they're at the forefront in South America in building their national Earth science and hazard reduction capacity."

Mario Ruiz, the principal seismologist at the Institute Geofisica, earned his master's in geophysics in 2004 from New Mexico Tech, where he studied with Aster.

"We hope to bring more Ecuadorian, students to New Mexico Tech and send ourfaculty and students down there," Rick Aster said.

Dunbar has already started to analyze the volcanic glass and crystal samples in her electron microprobe laboratory at the Bureau of Geology at New Mexico Tech.

Each of the Tech scientists said Ecuador is vibrant and inspiring.

Knox said the Ecuadorian people take seismic safety quite seriously, largely due to the proximity of metropolitan areas to active volcanoes.

"The level of hazard is tremendous," Dunbar said. "There's a big steaming volcano -- Guagua Pichincha -- looming over the capital city, Quito, so there's good reason to think about science."

"When the volcanoes start to rumble and shake, people become concerned," Knox said. "Volcano seismology is relevant. People have to worry about hazards."

Ecuador has five active volcanoes and overlies a major subduction zone. Johnson selected Volcan Tungurahua as the study site because it has proved to be a reliable source of both seismicity and infrasound data. Since it started erupting in 1999, the volcano's vent has typically stayed open, providing the ultimate outdoor teaching laboratory where students can deploy instruments for just a few days and collect significant data, he said.

Johnson is an international leader in the growing field of studying infrasound waves, the sub-audible, low frequency sound waves created by volcanoes, volcanic earthquakes and other phenomena.

His course focused on the deployment and maintenance of acoustic-seismic arrays, data processing and physical volcanology. Johnson taught students about volcano seismology, video and infrasound instrument deployment. Students collected and retrieved data, then processed and analyzed the infrasound data. The course was equally divided between field work, lectures, physical volcanology field trips and hands-on data analysis.

The course is the second summer expedition Johnson has led. The 2008 field course was in Hawaii and was 1 1 days long. He plans to alternate summer field courses between Ecuador and Hawaii.

"Primarily, it was a teaching class," Johnson said. "But we also recorded some very high quality data, thanks to the fact that the volcano was very cooperative. We entered the expenment when it was erupting nearly continuously."

Volcan Tungurahua erupted five to 10 times each day and periodically produced large "cannon shots."

"Those cannon shots produced excellent signals that we can use to study eruption physics," he said. "We were were for a 12-day deployment and we hit it just right with a nice level of activity with a reliable source of volcanic earthquakes and infrasound."

The team set up camp in the vacation town of Banos at the foot of Tungurahua, which towers to 16,500 feet. During die first week, Johnson and the students deployed a seven-station seismic array and a 10-compo-nent infrasonic network.

Johnson and Tech graduate student Omar Marcillo, a native of Ecuador, taught the students how to set up infrasound recording instruments and seismometers and how to analyze data.

During the first week, the class witnessed a rare occurrence -- a rain-mobilized ash flow, or lahar, tumbling down one of Tungurahua's drainages.

"We serendipitiously stumbled upon some signals that were associated with lahars," Johnson said. "Anyone can watch a volcano erupt, but to be able to watch a lahar is rare. That was especially exciting. Plus, lahar signals are of interest because they are a principal volcanic hazard."

Niranjan Khalsa of New Mexico Tech was one of two undergraduate students on the trip. She was effusive with praise for the quality of the learning expenence.

"It was amazing," she said. "We got to do everything from start to finish. I had no experience with seismometers or volcanoes, so it was super cool and fun."

The students helped scout locations to place two arrays of instruments. Each station was placed in a trash-can-style bucket and buried in the mountainside. The stations were roughly 100 meters apart and set in roughly a cross-shaped configuration. The first array of seven instruments included both infrasound microphones and seismometers. The second array was just infrasound. In addition, the team set up time lapse cameras trained at the volcano.

"This is a novel class," Johnson said. "Lots of folks do field science, but they are usually geologically focused. This is fundamentally different in that we brought our hardware to understand and record ongoing earth movements using geophysics. Our students had the opportunity to get dirty in die field and gather their own data."

During the second week, the group set out on a whirlwind volcano road trip while waiting for the Tungurahua instruments to collect data from volcanic earthquakes. After the weeklong tour, the group returned to Banos for instrument redeployment and a week of data synthesis and interpretation.

Knox is studying volcano seismology and had plenty of expenence with the instrumentation prior to the trip. She has worked abroad as a professional engineer and participated in a New Mexico Tech research expedition to the Mount Erebus Volcano in Antarctica. The Ecuador trip was unique, she said.

"\bu can read a lot of papers and text books, but when you are standing on a volcano, looking at the deposits, hearing it and feeling it erupt and explode, it gives you an intuitive feeling about the processes going on," she said. "Tungurahua is a dynamic volcano with cannon shots, earthquakes and lahars. We began to develop an understanding of a broad spectrum of volcanic activity."

Johnson said each small eruption was especially satisfying to experience, knowing that die corresponding elastic wave radiation was being recorded.

Knox, Khalsa and Johnson each said the three-week course was intense and focused. Johnson said die students were a cohesive and motivated group.

"People grabbed the bull by die horns and worked hard to get results," Knox said. "We got up early and worked late and the energy was really high, which probably is why the class was so intense."

"We had a lab set up at die base of the volcano," Johnson said. "We had six computers and all die software and we just set up shop at Tungurahua. The students did an excellent job of synthesizing seismic activity and doing an array of analyses."

Students divided into small groups to analyze seismic and infrasound array data. Students identified uieir own projects of interest and, on the final day of die course, they presented reports at die Institute Geofisica in Quito.



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© 2009 Mountain Mail Socorro, New Mexico. All Rights Reserved. This content, including derivations, may not be stored or distributed in any manner, disseminated, published, broadcast, rewritten or reproduced without express, written consent from DAS.

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