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October 9-13, 2000
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Volcano Chasers
| When Volcanoes Awaken |
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The lives of 23,000 people might have been saved if the Volcano Disaster Assistance Program had existed in 1985. The victims died from the eruption of the Nevado del Ruiz volcano Colombia. What can the scientists from this program learn about active volcanoes in order to save lives? The Volcano Disaster Assistance Program (VDAP) is located at the U.S. Geological Survey's Cascades Volcano Observatory in Vancouver, Washington. VDAP consists of a small staff of scientists and portable monitoring equipment. When a call comes in, they quickly fly out with their equipment to help local scientists. Of the more than 1,500 potentially active volcanoes worldwide, most are located in developing countries and are not regularly monitored. According to Dan Miller, head of the VDAP program, the job is not easy. Scientists have to gather and interpret data to help public officials in foreign countries make good decisions. "These kinds of decisions are incredibly stressful," Miller says. "They affect people's lives and the economics and politics of a region. Scientists are really put on the spot." In 1991, a mountain called Pinatubo in the Philippines began to show signs of volcanic activity. John Ewert was one of the VDAP scientists who traveled there. He describes how the volcano re-awoke: "On April 2,1991, there was a small steam explosion, and it opened up a crack two kilometers long. It destroyed several square kilometers of jungle. There was an earthquake swarm that went on afterwards. This was the first activity anyone had ever seen from this area." VDAP scientists were invited to give support to local scientists. "When we get a call, it's typically always Friday at 3:30 in the afternoon, and I think that was the case on Pinatubo," says Ewert. VDAP scientists established a temporary volcano observatory at nearby Clark Air Force Base and spent the next two months collecting data. In early June, seismic activity began to increase sharply. Several days later, scientists raised the alert level to start an evacuation. On June 15, 1991, the entire air force base and surrounding area was destroyed. |
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| The Technology and Equipment |
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If you were to design an effective portable lab for the VDAP scientists, what kinds of challenges and problems would you need to consider?
VDAP's monitoring equipment is sometimes referred to as a "volcano observatory in a box." It contains the standard equipment used at observatories, but this equipment is fine-tuned for the special conditions in which it will be used. According to Ed Klimasauskas, public information specialist at the Cascades Observatory, "one of these kits can be installed in a relatively short period of time on the slope of a volcano that is showing signs of restlessness." The VDAP team uses equipment under very harsh conditions; equipment is frequently destroyed by mudflows, rock falls, or lightning. To be effective, the equipment used by VDAP scientists must be able to:
Why less than 70 lbs? That's the airline-imposed weight limit for checked luggage! There are two types of portable volcanic monitoring systems: seismic and tilt. Seismometers measure earthquakes. Tiltmeters measure the changing degree of slope. Increases in seismic activity can mean that magma—molten rock deep in Earth—is flowing under the volcano. Flowing magma pushes against the ground, causing it to vibrate. These vibrations are earthquakes. Increases in tilt can tell the scientist in which direction the magma is moving. As one section of a volcano's lava dome inflates, the ground beneath the moving magma tilts. No single type of measurement tells the entire story, so scientists rely on a variety of equipment to get a more complete picture of what is happening underground. Scientists take the portable labs into the field and bury them on the flank of the volcano. Each box contains a radio that sends data back to the observatory for the scientists to analyze. Increases in seismic and tilt activity can mean an eruption might occur soon. When the data indicates an impending eruption, the VDAP crew make their recommendations to the local authorities, who then order evacuations.
John Ewert recalls the team's arrival at Mt. Pinatubo: "One of the first things that was done, along with putting in additional seismic instrumentation, tiltmeters, and making gas measurements, was to look at the eruptive history of the volcano as told to a volcanologist in the deposits around the volcano. Charcoal samples were collected from some of the deposits, and we had them dated very quickly."
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| Data Monitoring and Collecting |
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What is it like to collect data at a volcano that is about to erupt? Depending on the terrain, scientists may drive a four-wheel drive vehicle into the jungle to dig sedimentary deposits, or helicopter to a crater to take gas samples from a vent. All the while, the volcano is rumbling and no one knows or can predict when a large eruption might occur. Collecting data and installing instruments on a volcano can be risky work. Volcanologists have died while collecting data. Says Dan Miller, "I don't think that most of us are afraid, although we are often nervous. We work quickly, and we make decisions to minimize the risk to our teammates. There comes a time when the actual activity escalates and eruptions are underway when our team refuses to go back into these dangerous places." At the observatory, scientists closely watch seismic activity and tilt. The USGS has developed an alert system that provides officials and local authorities with information on the degree of volcanic activity and tries to forecast the likelihood of an eruption. Frequently they are accurate in predicting the explosion, as they did at Pinatubo. But volcanoes are not predictable. Soufriere Hills, a volcano on the Caribbean island of Montserrat, erupted two years after all signs indicated an imminent eruption. Dan Miller says that he is frequently asked why the United States should support an international volcano crisis team. "If we wait until the next volcano erupts in the lower 48 states, we might have to wait for a half century or more," he explains. "By having a crisis response team that responds to volcanoes around the world, we are able to broaden our scientific experience. We're able to develop new and better scientific tools and monitoring equipment. We're able to have a team of scientists that is very experienced in dealing with explosive volcanism. It means that we're going to be much better prepared for dealing with the next volcano crisis in the U. S. than we would be if we just sat here and waited for our volcano to erupt." |
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