Alaska volcano could be on the verge of massive eruption

ANCHORAGE — One of the most active volcanoes in the Aleutian arc could be working toward a massive, explosive eruption that could affect air travel, scientists said Thursday.

Satellite images of Pavlof Volcano taken Thursday showed strong thermal readings, consistent with what the Alaska Volcano Observatory is calling a "vigorous eruption of lava" at the volcano about 590 miles southwest of Anchorage on the Alaska Peninsula.

The volcano lies directly in the path of hundreds of daily international flight paths, and an explosive eruption could severely interrupt those operations, said Steve McNutt, a volcano seismologist with the observatory.

"What our concern is, is that there will be a more explosive eruption," McNutt said. "This is right up under the international aviation routes, so a big plume could pose a significant threat."

The Federal Aviation Administration didn't immediately return a phone message left by The Associated Press on Thursday seeking comment.

Volcanic ash can enter an engine and make it seize up, McNutt said.

McNutt said seismic activity is high at the 8,262-foot volcano, with about one tremor recorded every minute. Mudslides — called lahars — caused when lava melts snow on the peak, have triggered some seismic activity as well, he said.

The mudslides took place on the southeast side of the volcano, an area he said is inhabited by few, if any, people. Pavlof is about nine miles from Pavlof Bay, a popular fishing ground, but at the moment it isn't posing an immediate threat, McNutt said.

He said hazards the volcano could present include light ash fall on nearby communities, mud flows, lava flows and hot debris avalanching on the volcano's flanks.

Several small towns are in the area, including King Cove, about 35 miles to the southwest, with a population of roughly 800, and Cold Bay, nearly 40 miles southwest, with a population of about 90.

Josh Gould, a co-owner of King Cove grocer John Gould & Sons Co., said people in town were preparing for the worst while hoping for the best. Sales of basic staples are up, he said, but there's no danger of running out of items like water, bread and milk.

He said the ash plume was visible from town, but none was falling on it yet.

Seismic activity was first picked up at the volcano Tuesday. Eyewitnesses aboard a fishing boat in the area Wednesday reported glowing lava on the volcano's southeast flank.

Pilots have reported a weak plume of ash drifting five miles to the southwest and likely below 20,000 feet, and the observatory has raised its alert level to "Watch." Its aviation color code has also been raised to orange.

"What we think we're in for is several months of low-level eruptions punctuated by a few large and explosive events," McNutt said.

The volcano has had about 40 historic eruptions — records here only go back to the 1760s — making Pavlof one of the most closely monitored volcanoes in the state, with permanent monitoring equipment installed nearby.

A string of eruptions took place during the 1970s and 1980s, McNutt said, but the last one took place in 1996, making this 11-year period the longest it has gone without an event.

A series of ash explosions and lava eruptions took place for several months after the last eruption. Ash clouds reached as high as 30,000 feet at the time. During a 1986 eruption, Pavlof spewed ash as high as 49,000 feet.

Pavlof is a stratovolcano, which means it is cone shaped and is built from the ground up as lava and ash layer upon each other during eruptions. During past eruptions, sporadic lava flow has gurgled out for several months.

Gould remembers the 1996 eruption, when a significant amount of ash fell on nearby King Cove.

"There was a few people who were kind of shook up over the situation, but we survived it," he said.