Amukta reported activity

Event Name : Amukta 1987/9

Start:

September 4, 1987

Observed

Tephra plume:
Central eruption:

Eruption Type:	Explosive
MaxVEI:	1
ColHeight:	300 m

Description: From Reeder (1990): "On 4 September 1987, flight engineer George Wooliver observed from his Reeve Aleutian Airways, Inc. Boeing 727 a small eruption plume from the top of Amukta Island. The dark tephra plume rose at least 300 m above the volcano and then drifted to NW for up to 1 km. George could visually see the NW side of the volcano, while the rest of it was covered by low altitude clouds. George's observations were made from a 9,750 m altitude at a distance of unfortunately nearly 120 km to N. George has fortunately flown the Aleutian Islands since the 1950s, and he is well experienced at observing Aleutian volcanic eruptions.

Normally the only activity of Amukta volcano is the very minor amount of nearly continuous steam emission from several small vents that are located just inside of the Amukta summit crater and on the very floor of the Amukta summit crater. This information is based on observations made by Harold Wilson of Peninsula Airways Inc., who has flown in the region regularly between September 1983 and July 1987."

From Smithsonian Institution, 1987: "At about 1000 on 28 August pilots Charles Kozler, Wayne Russell, and George Wooliver (Reeve Aleutian Airways) reported an eruption plume reaching 10.5 km altitude in the vicinity of Amukta, drifting WNW. The FAA issued a NOTAM warning pilots to stay 25 miles [40 km] from Amukta Island. Heavy weather clouds covered Amukta Island so its activity could not be directly observed. Mt. Cleveland, 100 km ENE, was apparently active that same morning and winds were blowing in the direction of Amukta (see Mt. Cleveland 12:08). The origin of the large cloud remains both uncertain and controversial at the time of this report.

"On 4 September Wooliver observed a small dark ash plume rising at least 300 m above the summit of Amukta then drifting as much as 1 km NW. Only the NW flank was visible because of cloud cover. His observations were made from 9,750 m altitude from nearly 120 km N. Wooliver has flown in the Aleutian Islands since the 1950's and is experienced at observing eruptions.

" Amukta's last known eruptive activity was on 12 July 1984 (BVE, no. 24). Harold Wilson (Peninsula Airways) notes that normal activity * * * is continuous minor steam emission from several small vents just inside the summit crater rim."