Strongly felt seismic activity that began the evening of Sunday, March 10, continued throughout most of yesterday, March 11. At 5 pm (AST) yesterday, the continuous tremor-like shaking reported by residents of the city of Akutan began subsiding. The intensity of felt shocks also began decreasing, and by 8 pm AST, the number of shocks began decreasing. The number of felt shocks decreased through the night and this morning. Poor weather conditions persist and continue to prevent visual observation of the volcano.
The felt-earthquakes and shocks in the city of Akutan on Sunday and Monday suggest that Akutan Volcano may be in low-level eruption, however, no confirming information is yet available. There is no seismic monitoring of the volcano. There are no reports of airborne ash or sulfur smell. Cloud tops are estimated to be at about 25,000 ft. (8 km) and local winds are to the north today. If any ash is being produced, it is localized. Without direct observation, we postulate that the eruptive activity (if any) is characterized by periodic low-level explosions.
Akutan volcano is located on west central Akutan Island in the eastern Aleutian Islands 185 km southwest of the tip of the Alaska Peninsula. The communities of Unalaska and Dutch Harbor, lie 50 km to the southwest. Akutan is a stratovolcano with a 2-km-wide summit crater with an active cinder cone. It is one of the most active volcanoes in the Aleutian arc with at least 27 separate eruptive episodes documented since 1790. The volcano frequently produces low-level eruptive activity including steam and ash emission.
AVO has no seismic monitoring equipment on the island but we are currently mobilizing personnel and equipment to install temporary seismic stations. AVO is closely monitoring the situation and will issue further updates as information becomes available.
PLEASE CONTACT AVO IF YOU HAVE ANY QUESTIONS OR COMMENTS: Terry E.C. Keith Chris Nye AVO Scientist-in-Charge (Acting) AVO Coordinating Scientist U.S. Geological Survey Geophysical Institute 4200 University Drive University of Alaska Anchorage, AK 99508-4667 Fairbanks, AK 99775 OFF= (907) 786-7443 OFF=(907) 474-7430 FAX= (907) 786-7425 FAX=(907) 474-5618 EMAIL=TKEITH@TARDADDY.WR.USGS.GOV EMAIL= CNYE@GI.ALASKA.EDU