Whitney Palmer

Healthcare. Politics. Family.

Taking the pulse of volcanoes

Published in the Jan. 10, 2011, Raleigh News & Observer and the Jan. 10, 2011, Charlotte Observer

BY WHITNEY L.J. HOWELL – CORRESPONDENT

CHAPEL HILL — North Carolina’s last volcanic eruption occurred at least 200 million years ago, so it might be surprising to find a volcanologist at the University of North Carolina-Chapel Hill.

But for the past 10 years, geological sciences professor Jonathan Lees has traveled the globe studying these natural explosions after being lured to the state to study geothermal fields with colleagues at both UNC-Chapel Hill and Duke.

Volcanoes are difficult to study by nature, but advances in technology – including satellite monitoring systems – make it easier to conduct research from afar.

Traditionally, researchers have gathered most of the data about eruptions from the earthquakes that precede them. As magma pushes to the Earth’s surface, it produces seismic waves – low-impact energy waves traveling through the ground – that are recorded by several seismometers

Jonathan Lees, a volcanologist at UNC Chapel Hill, uses equipment to monitor the Reventador volcano in Ecuador and gather data about eruptions. Research helps get closer to pinpointing what to expect and when. PHOTOS COURTESY OF MIKE WELSH

spaced around the volcano’s surface.

 

These details pinpoint the location, time, depth and magnitude of the resulting earthquake, but they provide few specifics about what the volcano itself does.

Lees gathers information about volcanoes by studying the speed of seismic waves and how they change directions, as well as their variations in intensity.

What happens in eruptions

In recent years, he added high-definition video to his arsenal of monitoring equipment. Linking the visual images to the acoustic findings captured by the seismometers creates a 3-D analysis of what occurs during an eruption. The technique could tell scientists more about how volcanoes behave even if forecasting precisely when eruptions will occur is not possible, Lees said.

“It’s a common misconception that volcanologists and seismologists can actually predict when a volcano is going to erupt,” said Lees, who has studied 10 to 15 volcanoes in South America, Europe and Asia during his career. “The work I do is focused on increasing our understanding and our appreciation of the dangers involved with volcanoes and to, hopefully, save lives one day.”

The U.S. Geologic Survey supports monitoring volcanic activity because it helps scientists anticipate, if not predict, an eruption and its potential scope. Public officials can use the information to protect populated areas if the need arises.

Every decade, about 160 volcanoes erupt globally, and up to 20 volcanoes are erupting at any given time, according to the Smithsonian National Museum of Natural History. In the United States, based on USGS data, there are 169 active volcanoes, and 54 are a high or very high threat to the public. The closest active volcanoes to North Carolina are on the West Coast, but there are two dormant volcanoes in Mole Hill and Trimble Knob, Va.

Geological researchers at Michigan Technical University estimate that 500 million people worldwide live close enough to a volcano to be at risk in the event of an eruption.

Learning about the volcano

To capture the most extensive information about eruptions, Lees and his team scatter recording stations, called nodes, evenly around the volcano. The terrain determines the exact location, but Lees said he tries to maintain a spiral, circle or straight-line pattern, choosing spots where the equipment is both out of danger and easy to retrieve.

Each node includes a seismometer; a custom-made, low-frequency microphone; Doppler radar that records the speed of particles as they fly away from the volcano; an infrared video camera to gather thermal heat images; and a high-definition video camera.

Solar panels are in place to charge the equipment batteries. When all of the collected data are reviewed together, they present a comprehensive, cohesive picture of a volcanic eruption, Lees said.

“Volcanoes are like labs, and we’re studying the details of what happens during explosions to hopefully apply our findings to all volcanoes,” he said. “Eventually, we hope to anticipate behaviors of particular volcanoes when they exhibit certain signals.”

For example, by watching video recordings of the Santa Maria volcano eruptions in Guatemala in 2007, Lees’ team discovered that the top of the volcano, called the crater, bulges moments before magma and hot gases break through. Frame-by-frame reviews reveal both the explosive force behind particles and the directions in which they fly.

Even though it is impossible to predict the time of an eruption, understanding more about how volcanoes behave prior to and during the explosions could fundamentally change how scientists investigate volcanoes, said Steve McNutt, a volcano seismologist with the University of Alaska-Fairbanks and the Alaska Volcano Observatory.

“Having a greater understanding of volcanic changes could eliminate our need to work retrospectively to try and figure out what happened,” he said.

Volcanoes pose more hazards than lava flow, McNutt said. Ash and other particles can create additional problems to nearby populations.

 

Lees installs the equipment. Volcanoes are hard to study, and scientists can't predict when one will explode.

“The ash and other debris that are launched into the air are real dangers to people who live near volcanoes. They are also risky for any aircraft that fly overhead,” said McNutt, who also studies the mechanical behavior of volcanoes. The volcanic eruption in Iceland last April caused extensive disruptions to air travel, grounding or re-routing flights to and across Europe for weeks.

 

“These hazards are a big reason why we’re doing this research,” McNutt said.

Additionally, the same characteristics that make volcanoes a threat to cities and populations make them a danger to scientific equipment. The steam, lava, and dust create a hostile environment that can destroy some of the data-gathering instruments.

Despite these threats, McNutt said, Lees’ 3-D data collections are necessary because his work provides details that are currently not available through other types of data gathering.

“With 3-D work, you put the equipment out, and it just keeps running. This way, we can learn how volcano systems change and evolve over time,” McNutt said. “All of this adds new increments of knowledge and gives us a more sophisticated understanding of how these environments act.”

A robotlike plan

In addition to continuing the 3-D data collection, Lees said he plans to expand his research by making all nodes wireless and having them feed information directly to one central computer. He envisions the next generation of recording stations will function like robots that can enter the more dangerous parts of a volcano’s terrain.

“I’d like to see hundreds or thousands of recording stations placed all over the volcanoes,” he said. “They’d be wired to talk to each other much like a brain, and they’d be cheap to produce so if we lost some in the riskier spots, it wouldn’t be a big deal to replace them.”

To read the Raleigh News & Observer article online: http://www.newsobserver.com/2011/01/10/909861/taking-the-pulse-of-volcanoes.html

To read the Charlotte Observer article online: http://www.charlotteobserver.com/2011/01/09/1967971/taking-the-pulse-of-volcanoes.html

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January 10, 2011 - Posted by | Science | , , , , , , , , , , , , , , , , , , , ,

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