A restless volcano near Alaska’s most populated region is being watched by scientists and officials, who warned Thursday of the risk of clouds of ash and a tsunami from a possible eruption.
The intensifying rumblings in the past few weeks at Augustine Volcano, an island peak 175 miles southwest of Anchorage in Cook Inlet, have produced a series of steam explosions, releases of sulfur gas and signs that there may be an eruption similar to events in 1986 and 1976 which sent ash clouds as high as 40,000 feet, scientists said.
There has even been an increase of 1 inch at the top of the 4,134-foot volcano, a sign that seismic activity is causing the summit to bulge slightly, said John Power, a seismologist with the Alaska Volcano Observatory, a joint office run by the U.S. Geological Survey and state agencies.
“All of these things are very typical of what you would expect to see in a volcano that is reawakening,” Power said.
Although there are no specific signs that an eruption is imminent, flight restrictions are already in place and there are plans to expand those if activity increases at the volcano.
If Augustine does erupt, that could result in grounded flights, school closures and even evacuations, officials said. It is also possible that there will be a landslide from the volcano into the waters of Cook Inlet, causing a tsunami, they said.
Such an event occurred in 1883, when a wave believed to be 20 feet high hit the Native Alutiiq village of Nanwalek, 50 miles east of Augustine.
“Any time you have a volcano on the water that’s erupting, common sense says you could have a flank collapse and a wave,” said Paul Whitmore, director of the West Coast/Alaska Tsunami Warning Center.
Anchorage is too far away to be at risk from an Augustine-related tsunami, Whitmore added.
But preparations for the possibility are well under way in Nanwalek, said Sergie Active, rector of the local Russian Orthodox church in the village of 200 people.
“We would have to go to higher ground, basically. The first thing is to have things packed away, just in case,” Active said in a telephone interview from the local tribal council office.
“We have asked all the households to have sleeping bags, clothes, food, first-aid kits — all the things that would be needed.”
Augustine is one of Alaska’s most active volcanoes, with five eruptive periods since the late 1800s, scientists said. Those events have generally started with major ash explosions that last a few days, followed by months of less powerful eruptions that produce oozing lava at the summit, they said. Reuters