Event Name : Amukta 1996/7
Start: | July 1996 | Observed |  |
Stop: | September 1996 | Observed |  |
Tephrafall: |
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Flank eruption: |
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Tephra plume: |
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Eruption Type: | Explosive | |
MaxVEI: | 1 |
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ColHeight: | 800 m |
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Description: From Neal and McGimsey (1997): "In early July (date not recorded but it was during the first week), AVO received a fax from the USCG which included a ship-based observation in the vicinity of Seguam Island. Crew noted a 'large plume of ash and smoke * * * from Amukta.' They estimated the plume to be 2500-3000 feet high, presumably over the summit of the volcano. USFWS workers on Seguam were notified but reported seeing nothing unusual in the direction of Amukta. Satellite images from around the time of the report showed nothing of possible volcanic origin.
"On September 18, AVO received a pilot report of an eruption at Amukta. An Alaska Airlines pilot described an ash plume rising about 1000 feet above the 3500-foot summit of the volcano during flights on both the 17th and 18th. The plumes extended southward about 10 miles before dissipating. Satellite analysis on the 19th showed a narrow cloud that extended 22 mi south-southeast of Amukta, but this cloud contained no ash signature in bands 4-5.
"We later received Alaska State Trooper videotape -- visual and infrared (IR) from a flight on September 18th. It shows a brownish ash plume rising in intermittent dark puffs (estimated at 30 second intervals by the flight crew) about 500-1000 feet above the summit, then drifting south (?). The video captures fallout of ash in progress on the flank of the volcano. The ash cloud becomes fairly dilute rapidly as it drifts downwind. As the plane passes over the volcano, the active vent was visible a secondary crater against the inner wall of the main summit crater which appears to be formed by coalescence of several separate steep-walled pits. A fresh (?) tephra ring defines the active vent, and the main crater rim and upper flanks are covered with brownish tephra."