The ash plumes extended an estimated 10 miles south over the Pacific Ocean before dissipating. Amukta is a poorly known, seismically unmonitored, and uninhabited island stratovolcano located about 230 miles east of Adak Island. It has erupted at least 5 times since 1760, most recently in 1987. Several periods of increased seismicity during the past 24 hours indicate that the eruption is episodic in character with ejection of incandescent material to elevations of probably less than 10,000 feet above sea level. Intermittent low level ash clouds were detected on satellite imagery during the past 24 hours.
Weather is poor and inhibits visual observations.
Spatter-fed lava flows emanate from the summit vent on occasion. Mudflows and some flooding could be expected in the Cathedral River valley north of the volcano. Airborne ash hazards to aircraft may be considerable if a large explosive event occurs but much less severe during a typical Strombolian phase. AVO has a seismic network of six stations near the volcano and will continue to monitor the volcano's eruptive activity. The summit hot spot seen by satellite imagery yesterday was not seen on early morning images.