- One of the largest and most active volcanoes on the Alaska
Peninsula near the settlements of Perryville and Chignik has grown increasingly
restless since the turning of the new year, sending up small ash plumes
and experiencing increased seismic tremors.
The Alaska Volcano Observatory on Tuesday upgraded Mount Veniaminof Volcano's
level of concern to yellow for activity considered higher than the normal
background.
The level of concern is up from green, indicating normal activity, but
isn't yet to the orange level when an eruption is expected to occur or
is occurring.
Veniaminof is about 300 miles southwest of the Kodiak city area. A large
eruption of the volcano would not have an effect on Kodiak.
Weak seismic tremors were observed starting Jan. 1 and increased slightly
over the next few days. Ash emissions were observed in images of Veniaminof
taken around 9:30 a.m. Tuesday.
At around 10 a.m. Tuesday a pilot flying at 14,000 feet noted small ash
emissions from Veniaminof, said Ken Dean, acting coordinating scientist
at the University of Alaska Fairbanks.
Later in the day, 19 separate ash bursts were observed from Veniaminof,
none of which escalated above 500 meters from the summit, Dean said. The
most recent reports from Perryville included constant ash emissions today
at around 10 a.m.
"Activity at this volcano has been on and off over the past year,"
Dean said.
There is no evidence from the seismic data collected at this time that
events larger than those already observed will occur, the AVO indicated
in a press release.
AVO warns, however, that steam and ash emissions may continue intermittently
and could pose a hazard to people and low-flying aircraft in the vicinity
of the active cone.
AVO monitors Veniaminof continually with a network of nine seismic recording
devices capable of detecting very small earthquakes beneath the volcano.
The AVO also monitors the volcano using satellite imagery collected every
four to six hours to detect changes in surface temperature, ash emission,
and ash cloud movement.
Veniaminof has erupted at least 12 times in the last 200 years. The last
significant eruption occurred in 1993-95.
During that period of volcanic activity, intermittent emissions of ash,
steam and occasional ejection of debris occurred, according to the AVO
Web site. Ash fall and rumbling noises were reported in Perryville, about
22 miles to the south, and a light dusting of ash was reported in Port
Heiden about 60 miles to the northeast.
A slightly more energetic eruption occurred in 1939, depositing several
centimeters of fine ash on areas within about 52 miles of the volcano,
including Perryville.
Minor explosions producing some ash also occurred as recently as 2002.
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