U.S. Agency to Help Chile Develop Volcano Early Warning System

By Cheryl Pellerin

Chaitén volcano in southeastern Chile began erupting without warning May 2 for the first time in 9,400 years, spewing volcanic ash and steam 17 kilometers into the air and prompting the hasty evacuation of 5,000 people from two nearby towns.

Two weeks after the initial eruption, at the request of Chilean President Michelle Bachelet, scientists from the U.S. Geological Survey (USGS) arrived to work with their counterparts at Chile's Servicio Nacional de Geología y Minería (SERNAGEOMIN) to monitor the volcano and provide real-time warning of continuing eruptions.

"There was virtually no instrumental monitoring at Chaitén volcano prior to the eruption," USGS geologist John Ewert said in a June 25 USGS podcast. "Without the monitoring, people nearby or at risk have almost no time to prepare themselves, their families or their possessions for what may be a life-altering event."

On June 13, USGS officials signed a letter of intent with Bachelet to help Chile establish a volcano early warning system.

The work in Chile was done with support from the U.S. Agency for International Development's Office of Foreign Disaster Assistance (OFDA).

Future work will be coordinated through the Volcano Disaster Assistance Program, a 22-year-old collaborative project between USGS and OFDA that has helped with volcano crises in Central and South America, the Caribbean, Africa, Asia and the South Pacific.

MAGMA RISING

An eruption occurs when molten rock called magma rises from its source or from an underground reservoir and breaches the Earth's surface as lava. As it rises, the magma fractures overlying rocks, causing earthquakes, and parts of the volcano deform as magma approaching the surface makes room for itself.

Volcano monitoring involves a range of measurements and observations that detect such changes at a volcano's surface. These can include real-time seismicity (earthquakes), ground movements caused by moving magma, geophysical properties like changes in electrical conductivity and magnetic field strength, gas geochemistry like the emission rate of sulfur dioxide and other gases, and groundwater temperature and level.

Wiring up volcanoes this way can cost $100,000 to $1 million, Ewert said. And along with sensors, volcano monitoring requires experts who can interpret the collected data and a protocol for communicating with and warning the public.

Each volcano is different, Ewert told America.gov, and the best way to evaluate the present behavior of a volcano is to study its past behavior.

On a Sunday morning in May 1980, for example, a magnitude 5.1 earthquake shook Mount St. Helens in Washington state and the mountain's north face collapsed in a massive rock debris avalanche. A nine-hour eruption followed, killing 57 people.

The deadly event, authors Robert Tilling, Lyn Topinka and Donald Swanson wrote in Eruptions of Mount St. Helens: Past, Present, and Future (1990), "provided a good test for scientists who faced the challenge of obtaining, relaying and explaining in easily understandable terms the information needed by the federal, state and local officials charged with land management and public safety. It should be reemphasized, however, that a quick response at Mount St. Helens was possible only because decades of systematic research before 1980 had contributed to a good understanding of the volcano's eruptive behavior and potential hazards."

SAVING LIVES

The United States has 169 or 170 active volcanoes - "depending on how you want to count them," Ewert said - half of which have some kind of monitoring, and volcano observatories in Alaska, Hawaii, California, Washington state and Wyoming. But "less than a third of U.S. volcanoes are anywhere near adequately monitored," he said.

Chile has 120 potentially active volcanoes, one volcano observatory and seven volcanoes with some monitoring.

As it is developed, Chile's volcano warning system will be modeled after a U.S. plan called the National Volcano Early Warning System that USGS and its partners in the Consortium of U.S. Volcano Observatories released in 2005. The consortium proposed that volcanoes be monitored at a level that is equal to the danger they pose to people on the ground and to military and commercial aircraft.

In this effort, USGS scientist John Pallister said, USGS will collaborate with SERNAGEOMIN in four areas: volcano early warning system development, volcano hazards analysis and assessment, volcano crisis response and scientific study of volcanoes.

"We're thinking and planning on doing a follow-up to the eruption of Chaitén," he said, "when conditions of the volcano allow us to go in and understand better how an unusual eruption like this had taken place, what causes it and what it portends for the future."

More information about the Volcano Disaster Assistance Program ( http://volcanoes.usgs.gov/About/Where/VDAP/main.html ) is available at the USGS Web site.

The Mount St. Helens VolcanoCam ( http://www.fs.fed.us/gpnf/mshnvm/ ) is available at the U.S. Forest Service Web site.

Source: U.S. Department of State

judythpiazza@newsblaze.com

   _   _