Sunday, March 15, 2009
What is the purpose of volcano monitoring?
In a speech full of criticism for President Barack Obama's stimulus plan, Louisiana Governor Bobby Jindal singled out one program for particular scorn. "Instead of monitoring volcanoes, what Congress should be monitoring is the eruption of spending in Washington," Jindal said, deriding the $140 million appropriated to the U.S. Geological Survey (USGS) for "something called volcano-monitoring" as one of the most egregious bits of pork to lard up the $787 billion stimulus package. But to those who live under the looming threat of flowing lava, it was a poor punch line. "Does the governor have a volcano in his backyard?" sneered Royce Pollard, the mayor of Vancouver, Wash. Since most of us don't, TIME asked Marianne Guffanti, a senior volcanologist at the USGS, to explain the dangers volcanic eruptions can pose, how to spot them before they happen and why being vigilant can be vital.
Can you explain what you do?
Let me walk you through what's happening at our Alaska volcano observatory, one of five in the country. [The others are in Yellowstone National Park, Washington State, Hawaii, and Long Valley, California.] We have seismic networks and other geophysical equipment monitoring a number of volcanoes in Alaska, including Redoubt Volcano, 100 miles southwest of Anchorage. The volcano is showing a lot of signs of unrest that probably presage an eruption. So we look at seismic data, webcams, radar data and satellite imagery; we make overflights in airplanes to observe; we take gas measurements. We try to pull all this information together to give the public the best practical information we have about what's likely to happen — whether we think it's going to erupt, whether signs of unrest are minor and will diminish — so that people can plan.
How precise can you be with your forecasting?
Once the volcano starts erupting, we get better and better. An eruption is usually episodic — there's some activity, then a pause. The hard part is pinpointing where it first starts up. We use a graduated alert system. Right now, Redoubt Volcano is at orange. At orange, the military might move some planes out of a vulnerable airport. I read that trucking companies are buying ash filters. When it's red, we hope to give them hours of warning.
Can you explain in layman's terms what indicators you're looking for?
The process we're following is the rise of magma from depth to the surface. That gives off signs. One of the most basic is earthquake activity. Magma, as it rises, breaks rock to make room for itself. As the pressure lowers on it, it degases; it's like opening a pop bottle. We pick up the vibrations from the gas and magma. Since the magma has to make space for itself as it rises, the surface of the volcano deforms and we can look for those deformations. Then that gas makes its way out of the ground into the atmosphere, and we can measure it there. At Redoubt, for example, it's melting glacial features. We have to put all of this together and make an estimate.
What may we not be aware of in terms of the hazards posed by volcanoes — both for people living in their shadows or for someone like me who lives thousands of miles away from one?
If you live close to a volcano, you have to be worried about flowing lava, flowing mud. Mudflows can go quite a distance — 100 km — down river valleys. If you live farther away, you're not going to be directly affected by those hazards, but you could very well be affected by the ashfall, which can travel a distance of hundreds of miles. Ash has also erupted with great force into the stratosphere. That's where jets are flying, and encounters between aircraft and ash clouds can be damaging and life-threatening. This ash is not like ash from a fireplace: it's little, pulverized pieces of volcanic glass that can melt in jet engines. The combination has stopped airplane engines midflight. Fortunately we're good at dealing with this hazard now. If you fly from Chicago to Tokyo, there are people watching out for you behind the scenes; you'll never know you diverted around a potential ash cloud.
How will you allocate the $140 million Governor Jindal cited during his speech?
That money is for many other projects besides ours. We will get a very small portion of this money.
So the governor was incorrect?
He was incorrect in ascribing the full amount to volcano-monitoring. [But] what we'll do is use a lot of the money for maintenance and modernization of our monitoring networks. We're trying to play catch-up. In the U.S., there are 169 active volcanoes or volcanoes that are capable of reawakening and 65 historically active volcanoes. In the last 30 years, there have been over 90 eruptions from U.S. volcanoes.
You can't stave off an eruption. How do you measure success and failure?
First, we want to save lives. If there's an evacuation needed, a civil authority will call it, but we want to give them the best information so that people can be moved out of harm's way. The other category is minimizing economic and social disruption during the period of unrest surrounding an eruption. If you've got volcano unrest and you don't know the extent of the eruption, you really tend to overreact when you don't need to. We can also give practical information — telling people about ash flow or when a mudflow is coming down a river valley — that has really high stakes. In 1985, an entire town in Colombia, Armero, was obliterated and [about] 23,000 people were buried alive when a relatively small eruption melted snow and ice on a volcano and sent it rushing down this river valley. Scientists knew the eruption had occurred, but the communications process broke down. People in bed or watching a soccer game were buried alive.
The worst can happen. It usually doesn't, but in large part that's because we have taken seriously these past disasters and tried to learn from them. I sometimes think we're victims of our own success. We have been able to mitigate the adverse affects of volcanoes through science. There have been no crashes of aircraft because we've gotten pretty good at diverting them. The hazard is what it's always been. Our ability to deal with it has improved.
What did you think of Jindal's comments?
Let me just say that my colleagues and I take our job and our mission very seriously. We are always ready and willing to explain what we do and defend what we do, because we believe in what we do. I'll leave it at that.