Pavlof Volcano Erupts Right on Time
A quiet Pavlof Volcano is pictured in the photo at left as the large cone to the right of center. The photo on the right shows Pavlof Volcano erupting after an eight-year slumber. The volcano exploded in September and continued to erupt throughout the winter. Photos by Steve McNutt (left) and Donald Morris (right).
Pavlof Volcano awoke from an eight-year slumber and began to erupt violently just two months after a new network of seismometers was installed on its flanks by a team of Alaska Volcano Observatory scientists from the Geophysical Institute.
One of the most active volcanoes in the world, Pavlof exploded in September and continued to erupt throughout the winter. While car-sized pieces of rock spewed out of the 8,261-foot volcano, the new network enabled AVO researchers to monitor the activity from the safety of their offices in Fairbanks and Anchorage.
The new network is part of AVO's Central Aleutian Expansion, which is designed to monitor active volcanoes in the Aleutian chain that have presented serious hazards to high-flying jet aircraft in the past. Funds for the new network were provided by the Federal Aviation Administration.
"Many people don't realize that about 10,000 passengers and most of the air cargo between eastern Asia and North America pass over Alaska's volcanoes every day," said Professor of Volcanology John Eichelberger, AVO's coordinating scientist.
The Pavlof network was installed by GI Volcano Seismologist Steve McNutt, Geophysicist Guy Tytgat, and graduate student John Benoit before autumn for a reason.
Pavlof has erupted 41 times since the 1700s, and the volcano's last three periods of eruption from 1973-'76, from 1980-'83, and from 1986-'88 all started with increased seismic activity in autumn. McNutt theorizes that Aleutian weather patterns may stimulate Pavlof's eruption cycle.
"In the fall, Aleutian low-pressure systems cause sea level to become deeper by about a foot," he said. "The increased water pressure on Pavlof's base may force magma to move in a way that is similar to squeezing a tube of toothpaste from bottom."
The Pavlof network is designed to provide AVO scientists with immediate information about the location and strength of earthquakes beneath the volcano. Such earthquakes, caused when molten rock rises toward Earth's surface, can be used to forecast an eruption or to confirm that an eruption is occurring.
The new network, which was installed by helicopter, is made up of 10 self-contained, remote stations designed to radio information about earthquakes to nearby King Cove, and then over telephone lines to the Seismology Laboratory in the Geophysical Institute. Similar networks were installed on volcanoes near Akutan and Dutch Harbor.
AVO is a cooperative project of the U.S. Geological Survey, the Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.