Event Name : Akutan 1991/9
|Start:||September 15, 1991 ||Observed|
|Stop:||November 28, 1991 ± 2 Days||Observed|
|Tephra plume: ||
|ColHeight: ||4500 m ||
|MaxVEI: ||2 ||
|Duration: ||About 2.5 months ||
From Reeder (1994): "Tephra emissions from the summit tephra cone of Akutan volcano began September 15, 1991, and have occurred up through November, 1991.
"* * * A fisherman from the Seattle based fishing boat Richards reported at Dutch Harbor that he observed from his fishing boat at about 0800 LT September 15, 1991, lots of black material being emitted from the summit tephra cone of the Akutan volcano that rose about 300 meters above the volcano and that drifted sharply to the NE. The black emission stopped by about 0900. Shortly after 0900, the volcano billowed white steam with some black material for a short time.
"An unknown fisherman other than the above reported at Dutch Harbor that he observed on September 17, some eruptive activity of Akutan volcano. He made this report without any knowledge of the September 15 observation.
"On September 17, pilot Darren Talmadge reported to the FAA Flight Service in Cold Bay, as observed from his MarkAir Express Caravan Cessna 208 during the morning, a very dark gray billowy eruption plume from Akutan volcano that went up to an altitude of about 2,400 m. Cloud cover obscured the volcano for the rest of the day. On September 29, Jodeanne Ryan of MarkAir Inc. observed at about 1315 an Akutan eruption plume from the 737 Boeing Jet that had just departed from Dutch Harbor at about 1305. The mushroomed plume had already formed above the volcano to an altitude estimated to be less than 2,400 m. The tephra plume was drifting slightly to the NE. Later on September 29, Mark Owen and his Trident Seafoods Corporation group observed 6 short-lived but impressive tephra plumes form above the volcano. The first three occurred at 1517, 1520, and then 1535. These plumes rose within at least 1 minute to an estimated 3000 m above the volcano as black to light brown tephra plumes that drifted to the NW. At 1800, the Russian yacht, Tarpon, of Petropavlosk-Kamchatsky as it was returning to Dutch Harbor from Seattle on the Pacific side of Akutan Island observed black smoke for 3 minutes hit the clouds above the erupting Akutan summit tephra cone. A beautiful tephra plume formed sometime between 2000 and 2100 that rose about 4,500 above the volcano as estimated by Mark Owen. The snow cover on the volcano, which was above the 300 m altitude, was white at the time. The upper part of the volcano was still covered with cloud, but the plumes could be seen above because the cloud cover was broken. Bret Joines of Trident Seafoods Corporation at Akutan reported that some fine ash could be detected the next afternoon in the Akutan village region over windowsills. Mark Owen also observed that the snow on the volcano was then ash covered.
"On October 11, MarkAir Express pilot Darren Talmadge observed during the day from his Cessna 208 Caravan two short-lived eruption plumes from Akutan volcano that reached altitudes of 2,400 m and 2,100 m, respectively. These occurred at about 1030 and 1100, respectively.
"The Trident Seafoods Corporation group at Akutan reported an ash dusting in the Akutan village midday on October 13 as noticed in the afternoon on windowsills. They also noted ash falling through the cloud cover in the afternoon of October 13 at the western end of Akutan Bay.
"On October 14, Mark Owen and his Trident Seafoods Corporation group at Akutan observed about 0935 an eruption plume form from the Akutan summit tephra cone that reached a height above the volcano of about 1,500 m. Pilot Nic Sias of Peninsula Airways Inc. observed from his Grumman Goose the same eruption plume, which he estimated reached a maximum height of 1,800 m above the volcano. The winds were out of the west. The Trident group reported nearly continuous steam and black smoke rising over 200 m above the summit tephra cone of the volcano for the entire morning with large blasting events such as occurred at 0935 about every hour. They felt eruptive activity was occurring earlier in the morning but they could not see it because daylight came just before the 0935 event. Bret Joines of Trident Seafoods observed 6 dark eruption events rising at least 460 m above the volcano between 1530 and 1730 on October 14.
"At 1600, the Dutch Harbor Weather Center (Alaska Aviation Weather Radio) at the Dutch Harbor airport also observed the eruptive activity from Akutan volcano. Jack Wood of OESI Corporation out of Sparks, Nevada, observed and videoed the from the northern part of Amaknak Island just north of the Dutch Harbor airport an eruption plume rise up to about 1,500 m above the Akutan volcano at a start time of 1721. The plume then drifted to the NNE.
"On October 18, Mark Owen of Trident Seafoods reported that the volcano was steaming continuously during the entire day, with at least six dark 460 to 600 m high short-lived plumes that trailed to the W. On October 19, Bret Joines of Trident Seafoods reported that the upper part of the volcano was completely covered by cloud, but that the visible 300 m snow line on the volcano was all black with ash all the way up into the clouds. Their last good snow was on October 15.
"Between 0800 and 1000 November 30, Michael Lockhart and Mark Owen of Trident Seafoods Corporation at Akutan village observed a fairly steady-state 600 m high white steam plume above the summit tephra cone of Akutan volcano. Mark had Michael climb the 700 m ridge N of Akutan village to observe between 1300 and 1500 the impressive eruption of Westdahl volcano to the ENE. During this time, Michael had excellent views of Akutan volcano, which was not steaming. He could see fresh ash north of the rim of the Akutan summit crater that must have been deposited within the last 48 hours since their last good snow."