ANCHORAGE, Alaska — Alaska's Pavlof Volcano sent ash and steam skyward Sunday but not enough to raise the aviation threat for international air carriers.
A satellite at 12:40 a.m. measured an ash cloud at 19,500 feet, just below the 20,000-foot threshold considered to be a major threat to trans-continental aircraft. The aviation warming level remained at code orange, a step below red, the highest of the four levels, said geologist Kristi Wallace of the Alaska Volcano Observatory.
Pavlof is an 8,262-foot volcano located 625 miles southwest of Anchorage on the Alaska Peninsula, the finger of land that sticks out from mainland Alaska toward the Aleutian Islands.
Residents of Sand Point, a city of nearly 1,000 on Popof Island about 55 miles east of the volcano, woke to find traces of ash on their vehicles.
"We have physical samples that are being sent to us," Wallace said. "I'm excited to see what those look like."
Jagged ash particles can plug filters of vehicles and damage engines but Wallace said the reports noted minimal ash.
"Both reports indicate film on their windshield, but they could see through it – gritty ash," she said.
Pavlof's latest eruption began May 13 and sent hot mud flow down the sides of the mountain. Sand Point residents have recorded the eruption with photographs posted on the Alaska Volcano Observatory website, Wallace said.
Seismic sensors indicate a continuous tremor at the volcano, Wallace said, that oscillates up and down.
"It's on this really steady rate that's still high," she said.
The volcano last erupted in 2007 and continued to do so for 29 days.
"Past eruptions have lasted weeks to months," Wallace said. "The 2007 eruption was, perhaps, short compared to past eruption in historical times. It's most common that eruptions at Pavlof go on for months."
The National Weather Service has forecast a change in winds on the peninsula. That could send ash northeast away from Sand Point and toward Nelson Lagoon, an unincorporated commercial fishing village of 46 about 55 miles from the volcano. The weather service in a special statement warned people to avoid excessive exposure to ash, especially if they have respiratory problems, and to protect critical electronics and other equipment from contamination.
Eruptions at Pavlof could recede, continue or magnify.
"For the most part, what we see at Pavlof is exactly what we're seeing now: really low level, ash-poor plumes, continuous activity," she said. "But there's always an opportunity for something to spike up to, say, 30,000 feet."
That would boost the warning level to red, she said.