Volcano Watch — Pavlof Volcano, Alaska

USGS geologist Tina Neal reports from HVO's sister observatory in Anchorage (AVO) that Pavlof, the recently awakened volcano at the tip of Alaska Peninsula, is spewing fiery fountains of lava up to 900 feet in the air. Peninsula residents first noted a red glow from the volcano on September 15 (see Volcano Watch, Sept. 20). By mid-day on the 16th, incandescent blocks the size of cars were exploding from the vent area amongst turbulent clouds of ash and steam. Reconnaissance flights over the last several days revealed intermittent fountains 30 to 900 feet high and a spatter-fed lava flow moving down a deep gully on the northwest flank of the volcano. Neal, who was on the staff of HVO from 1983 to 1986, said "the fountains look just like Pu'u 'O'o."

Pavlof is the most active volcano in Alaska, having erupted 40 times since the late 1700s. Like many Alaskan volcanoes, it is known to geologists as a "wet" volcano because its summit is covered with snow and ice. Rapid melting during an eruption can lead to violent, steam-rich explosions, much like the events witnessed on September 16th. Rivers of hot water carrying a jumble of broken rock and ash, or "mudflows", which clog river channels and cause flooding on the flanks of the volcano, may also be produced.

Given its past history, the current activity at Pavlof may continue for months-- the previous eruption lasted for two years (1986-1988). According to Neal, towns nearest the volcano, Cold Bay (37 mi), King Cove (30 mi), Sand Point (60 mi), and Nelson Lagoon (50 mi), can expect light ash fall, depending on the wind direction. Mudflows and associated flooding may occur in the Cathedral River valley north of the volcano. Should a large steam explosive occur, airborne ash may pose a hazard to aircraft, but is not expected to be a problem during typical lava fountain events.

For more information on Pavlof Volcano, check the Alaska Volcano Observatory web page at http://www.avo.alaska.edu/.

Volcano Activity Update

Meanwhile, Hawaii's most active volcano, Kīlauea, continues to erupt with lava flows pouring into the ocean in Hawaii Volcanoes National Park. There were no felt earthquakes on the Island last week.