Alaskan Volcano Heats Up After 20 Years of Rest

Author:  Schwartzman Nina
Date:  May 2009

Although it's still winter in Alaska, one of its volcanoes has begun to heat up. Starting the night of March 22, Mount Redoubt, located 106 miles southwest of Anchorage, began to spew ash over the south-central part of Alaska. This was just the beginning of a series of explosive eruptions that have been shaking the state.

The Alaska Volcano Observatory (AVO), which monitors volcanic activity in Alaska, reported five eruptions on the night of March 22. The eruptions produced ash clouds up to 60,000 feet. "That's a very high plume," AVO geophysicist John Power said at a press conference the next morning. "That's about as high as they go." AVO later announced on April 3 that Redoubt was actively forming a lava dome. Lava domes form when viscous lava solidifies into a mound around the lava source.

Researchers had been anticipating the eruption since last summer, when nearby residents reported a sulfur smell in the area of the volcano. "This activity is something we've been expecting to see at Redoubt," Power reported. "We first began tracking unrest at Redoubt in July of 2008." Starting in late January of this year, scientists at AVO noticed a hike in seismic activity, and predicted an eruption within days or weeks. However, that eruption did not occur for nearly two months.

Seismic activity levels were up and down throughout February and March, reported Cheryl Cameron, a geologist at AVO. "We went through some periods of highly elevated seismicity, and we went through some periods when seismicity was barely elevated." This situation is very different from the last eruption in 1989-90, which began just one day after heightened seismicity.

Researchers cannot tell how long the volcanic activity will continue. The 1989-90 eruption lasted four months, and Cameron reported that this eruption could have a similar time frame. "Right now we have no reason to believe that [this eruption] wouldn't last that long." Since the initial activity, AVO has reported continuing periodic eruptions, as well as heightened seismic activity.

Hazards from the volcano include volcanic ash, which poses air quality issues and can destroy jet engines. Although the ash has so far missed the nearby city of Anchorage, it has reached towns more than 150 miles away and has caused cancellations of flights into the Anchorage International Airport. Also of concern is flooding due to the melting of the Drift Glacier. Melt water can create lahars, or volcanic mudslides, which can be dangerous due to their size and speed.

Written By: Nina Schwartzman

Edited by: News and Features Editor Brittany Raffa and Professional Reviewer Renee Gilberti

Published by Falishia Sloan