New data sheds light on volcano forecasting

File photo/Peninsula Clarion Steam and small quantities of ash drift to the south of Mount Redoubt April 4, 2009 at sunset on the end of a day that marked the volcano's most explosive eruption of the year's activity.

Before Redoubt Volcano erupted in 2009, scientists detected unique events that now add to their understand of how volcanoes function, according to a study this year.


Tremors often ripple through a volcano before it explodes. They indicate a looming eruption — at least that’s what volcanologists thought before Redoubt’s 2009 eruption, said Diana Roman, a scientist for the Carnegie Institution of Washington and the study’s team leader.

But the Redoubt eruption was different. Its tremors began six to seven months before the volcano exploded, according to the Carnegie Institution study. The study also documented increased ground swelling and gas flow in the volcano’s magma prior to its eruption.

Now, Roman said, Alaskan volcanologist — and other scientists globally — know that tremors do not always foreshadow an impending eruption.

Roman and her team’s findings add to a more comprehensive understanding of the big question: “What’s happening next?” Roman said.

“The more detail you can look at data in real time, the more information you can have to forecast,” she said.

Volcano forecasting builds on each data set and each study to produce quicker response times, said John Power, scientist-in-charge at the Alaska Volcano Observatory. In 1989, the observatory sounded its first warning 18 hours before Redoubt erupted, he said. But, in the 2009 eruption, the observatory released its first warning four months before the volcano erupted, he said.

Power said Redoubt’s 2009 eruption has been a “gold mine of data.”

“This has helped us understand how volcanoes like Redoubt can build from their normal, quiet state to an eruption,” Power said.

Currently, Redoubt, Augustine, Iliamna and Mount Spurr volcanoes — the four volcanoes west of the Kenai Peninsula — are at normal activity levels. When they do erupt, the Kenai Peninsula Borough Office of Emergency Management begins coordinating with the Alaska Division of Homeland Security and Emergency Management and the Federal Aviation Administration, said Scott Walden, the borough’s office of emergency management director.

But by then, he said, emergency efforts are already behind. Every second of lead time matters, he said.

“It would help our planning to start before it occurred,” Walden said.

Also, volcanologists do not know how long an eruption will last, he said. Augustine’s 2006 eruption lasted for two months, and Redoubt a similar amount of time, according to volcano observatory documents.

During both eruptions, the volcanoes covered parts of the Peninsula in a fine layer of dense, abrasive ash, he said. The ash tore through engine blocks and ripped apart business’s air filters, he said.

“The problem we saw with the volcanoes isn’t so much lava but the air quality,” he said.

More lead time would allow the Peninsula office of emergency management to prepare residents more quickly, so they can protect their property, he said.

Carolyn Driedger, hydrologist and outreach coordinator for the Cascades Volcano Observatory, said scientists’ collective understanding of volcanoes grows inconsistently. Sometimes researchers will publish a study others see as “heresy” until it is proven, she said. Other times studies immediately dumbfound the community, she said.

But, every eruption and every study improves scientists’ understanding of volcanoes, she said. The 2008 Mount Saint Helens eruption drew an international community of scientists, she said.

“We help one another,” Driedger said. “What happens there in Alaska helps us here in the Cascades.”


Dan Schwartz can be reached at


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