Volcanologist  Interviews

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Jim Garvin works for NASA, but his feet are firmly planted on Earth.

"NASA is about space," explains Garvin. "But included in NASA's charter is the big job of scientifically exploring the universe, which naturally includes our local solar system and even our home planet Earth."

Volcanoes are dominant landforms in our solar system. They tell us how planets regulate their temperatures. "Just as human beings sweat when it's hot, volcanoes are critical to the regulation of interior temperatures on planets," says Garvin.

Like Garvin, Lori Glaze is involved in NASA's "mission to planet Earth," but she spends her time studying volcanic gases and plumes from satellite images.

"Volcanoes put out a lot of sulfur dioxide gas," says Glaze. "When it gets into the stratosphere, it can actually cause the Earth's surface temperature to cool. Eruptions can have a weather impact over a couple of years' time.

Glaze remembers when the volcano Pinatubo went off in 1991.

"The next year or two, there were some bizarre weather patterns -- flooding in the Mississippi valley, brilliant sunsets and the exaggerated El Nino [a warm ocean current along the western coast of the U.S.]. All of these things were somehow related to the Pinatubo eruption."

If volcanoes tell us about planet Earth, what about volcanoes on other planets?

"I'm working on a paper right now about lava flows on Mars," says Glaze. "We're trying to find out how runny the lava is, how far it gets before hardening.

"In the last few years, I've been involved in looking at explosive eruptions on Venus, seeing if it's possible to have an explosive eruption with the high air pressure on that planet. I'm also hoping to do some work studying Io, a moon of Jupiter."

Garvin has had some interesting times studying Icelandic volcanoes. In fact, it was an eruption in Iceland that helped to get him interested in this field when he was young.

"As a child, I lived abroad in the Middle East and in Australia. I saw volcanic landscapes in Italy, Jordan, Greece and later New Zealand. Then I read in the newspaper about the eruption at Surtsey from 1963 to 1967 in Iceland.

"While visiting New Zealand as a 12-year-old with my parents, I observed geothermal energy at work and a pyroclastic field of rocks near an explosive volcano. This touched me and from then on studying landscapes affected by volcanoes has captivated me."

His passion for the volcanic landscape took Garvin to Brown University, where he received his PhD before joining NASA. Since then, he has made numerous trips to Iceland to work. He led an aircraft remote sensing experiment over the volcanic island after an eruption underneath a glacier.

"My activities included planning the over-flights, working with our excellent NASA pilots in a NASA Wallops Flight Facility P-3 aircraft, interfacing with the engineers operating our scanning laser altimeter sensors and imaging systems, and conducting post-flight ground truthing observations."

In other words, Garvin flew over the volcano dozens of times and took nearly one billion measurements of the landscape affected by the October 1996 eruption.

"We also surveyed the damage done when the ice that was melted by the eruption flooded the south coast. It was a catastrophic event, known in Iceland as a jokulhlaup."

Ultimately, the big thrill is watching an eruption up close. Glaze relates her first experience:

"It pretty much blew my mind. I was at Mount Etna in Italy, and it was just tremendous. It was closed to the tourists, but we were the science crew, so we were maybe half a mile away. There were these giant fountains of lava at the summit, and we were getting hit on the head by one- to two-inch blocks of ash and cold lava."

Glaze says there were also active flows of lava moving down the slopes. Once the surface cooled enough to harden, the scientists decided to climb around on top of the flows. You have to wear good boots for that.

"I went through a good pair of boots pretty fast," admits Glaze. "You can smell the rubber melting as you walk across. And the hardened lava is basically glass, so it tears your shoes to shreds. It's very sharp. But it was a blast."