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Kanaga Volcano continued to erupt minor amounts of ash over the weekend, interfering with local air traffic and dropping a light dusting of ash on the community of Adak located 33 km east of the Central Aleutian volcano. As of midday today, AVO analysis of satellite imagery indicated a possible plume containing minor ash, drifting generally east-southeast from the volcano over Adak. The Federal Aviation Administration enforced a 15-mile restricted flight zone around Kanaga until 2:30 PM to minimize the possibility of aircraft encountering an ash cloud during instrument approach and departure. Poor weather obscured the volcano through the morning, however no ash cloud was seen from Adak as visibility improved through the day. Based on the last eight months of activity, continuing episodes of ash eruption accompanied by avalanching of hot debris down the volcano's flanks can be expected. Depending on wind conditions and the size of a given eruptive episode, additional fallout of ash on the community of Adak is possible.
The current phase of activity at Kanaga began in December 1993. Thus far, the eruption has been characterized by intermittent, low-level steam and ash emissions producing plumes rising rarely over 10-15,000 feet ASL and drifting a few tens of miles downwind. This past weekend, following an increase in intensity of ash emission, numerous residents of Adak and boat traffic in the area noted a fine dusting of ash on the ground. Today, the Alaska Volcano Observatory learned that over the past few months, several very light dustings of fine ash on the northern portions of Adak had occurred. Samples of this fallout are being sent to us for further analysis. Pilots and other observers also continue to report and photograph avalanches of hot fragmental debris cascading down the north flank of the volcano into the ocean. While we have been unable to clearly discern the source of this material, it likely represents collapse of a growing lava dome or ejection of hot blocks of lava from near or within the summit crater.
There are no seismometers on Kanaga Volcano and monitering of the continuing eruption is done through a combination of satellite image analysis and real-time observations by pilots and residents of Adak. To date, eruptions plumes containing some ash have generally not exeeded 10-15,000 feet ASL. While our tracking of ash fallout from this volcano is limited due to the remote, island setting of Kanaga, it would appear from satellite imagery that detectable fallout has thus far been confined to within a few tens of miles of the volcano.