US pins down volcano risk
Volcanologists push for better monitoring of threatening activity.
After spending more than a year assessing 169 active volcanoes in the United States and the Mariana Islands, experts have identified the volcanoes that pose the greatest threat to people and property.
The US Geological Survey (USGS) report, issued on 29 April, also pins down what steps should be taken to fill the gaps in the current monitoring systems for those volcanoes.
"We know that many of the most damaging effects of eruptions can be mitigated if proper monitoring is in place," says Marianne Guffanti, a volcanologist with the USGS, which is headquartered in Reston, Virginia. "That's what this report is all about."
But for volcanoes that have not been studied and are not being monitored, researchers have little hope of predicting an eruption. "We know there are many under-monitored volcanoes in the United States," says Guffanti.
The USGS report ranks each volcano based on the characteristics of its eruption (whether it would spew fast- or slow-moving lava, for example), how often it tends to erupt, whether there are major developments in the area, how close the nearby airports are, and how many passengers fly over it each day.
The results include a top-ten list of the most dangerous volcanoes (see 'Ten most hazardous US volcanoes'). The volcanoes highlighted as priorities include five volcanoes that are currently erupting or showing unrest, such as Mount St Helens in Washington; 13 very threatening volcanoes that are inadequately monitored, most of which are in the Cascade Range on the west coast of North America; and 19 volcanoes that pose a great threat to aviation safety but have no real-time sensors for volcanic activity, many of which are in Alaska.
Sooner not later
Guffanti notes that people often rush to monitor a volcano only after it has erupted and proved that it is dangerous. But this is a bad idea, she says, “It is difficult and risky to play catch-up with a volcano.” In 2002, for example, hundreds of thousands of people were forced to evacuate and dozens of people died in the eruption of Goma volcano in the Democratic Republic of Congo. Scientists scrambled to improve monitoring equipment at that volcano only after the eruption took place.
Japan, on the other hand, is known for its proactive approach to monitoring volcanoes and for applying the most advanced technology to that quest. "We have a lot to gain by looking at what's going on in Japan," says John Eichelberger, a volcanologist at the University of Alaska in Fairbanks.
In order to address the gaps in monitoring identified by its report, the USGS suggests setting up a National Volcano Early Warning System. Among other things, the system would enhance the monitoring of the most dangerous volcanoes, establish a watch office that would run 24 hours a day, seven days a week, and aid the sharing of data between observatories.
"This is the most thorough and quantitative effort I've seen for focusing resources on the volcano hazards problem," says Eichelberger.
The USGS plans to polish the warning-system proposal with input from other federal agencies, local officials and businesses. The report's authors hope that the framework will be phased in over the next eight to ten years.