Science

On Alaska Peninsula, another volcano awakens

Another Alaska volcano has grumbled to life. Pavlof Volcano, an 8,261-foot peak on the Alaska Peninsula, awoke Monday morning, kicking off a "low-level eruption of lava," according to the Alaska Volcano Observatory. Pavlof, about 30 miles northeast of the community of King Cove, is a frequently-active volcano that last erupted in 2007.

Shortly after 11:30 Monday, the AVO posted the following update to its website on the status of Pavlof volcano:

Seismic activity at Pavlof Volcano increased this morning commensurate with the presence of an intense thermal anomaly at the summit observed in the latest satellite imagery. Similar patterns of seismicity and elevated surface temperatures have previously signaled the onset of eruptive activity at Pavlof. Although not yet visually confirmed, a low-level eruption of lava has likely begun from a summit vent. No ash clouds have been detected.

The AVO also elevated the alert level at the volcano to "orange," indicating heightened activity and possible further eruption.

Unlike Mount Cleveland -- a remote volcano located on a small Aleutian island and the only other volcano exhibiting activity in the Last Frontier at the moment -- there is an extensive monitoring system set up at Pavlof due to its location and how often it's active.

"There's a full seismic network on Pavlof," said Game McGimsey, a staff volcanologist with the AVO. "It's historically about the most active volcano in the Aleutian Arc ... it's had around 40 or 41 eruptions. It doesn't have large eruptions, but it erupts frequently." There is also satellite imagery and usually a webcam monitoring the peak, though that camera is currently offline, McGimsey said. An FAA webcam stationed at Cold Bay can see Pavlof on clear days.

Reports of possible eruptions at the volcano date back to 1762, when historical accounts suggested an eruption in the area, though that activity may also have come from Pavlof Sister, another eruptive peak very close by. The most recent eruption at Pavlof, in 2007, featured spitting lava and small ash clouds during a month-long stretch of heightened activity.

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"Nothing unusual was observed during the summer of 2007 and the seismicity was at background levels through Aug. 13," the AVO reported in its summary of the eruption. "Abruptly on the morning of Aug. 14, the five-station seismic network on Pavlof began recording low-frequency earthquakes occurring at a rate of two to seven events every 10 minutes, a pattern that had preceded eruptions in 1996, 1986, 1983, and 1981."

McGimley said he expects this most recent activity to resemble the 2007 event. Pavlof does not have a large caldera where lava builds, but rather numerous vents around the peak where gases build up and lava escapes.

In such "fountaining" events, he said, "a bubble of lava rises to the surface and sort of 'pops' and spews out chunks and blobs of lava."

This is also different from the often-active Cleveland volcano, which usually sees a slowly building lava dome, which can lead to further eruptions and bursts of ash from the caldera. Cleveland was upgraded again on May 4, when satellite imagery caught a small event at the peak.

Keep an eye on Pavlof, and Alaska's other volcanoes, at the Alaska Volcano Observatory.

Contact Ben Anderson at ben(at)alaskadispatch.com

Ben Anderson

Ben Anderson is a former writer and editor for Alaska Dispatch News. He left the ADN in 2017.

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