Event Name : Shishaldin 1976/4
|Start:||April 6, 1976 ||Observed|
|Stop:||February 27, 1977 ||Observed|
|Lahar, debris-flow, or mudflow: ||
|Incandescent gas jet: ||
|Tephra plume: ||
|Central eruption: ||
|MaxVEI: ||2 ||
|Duration: ||Intermittent for about 10 months ||
From Shackelford (1978): "From April to November 1976 Shishaldin volcano occasionally displayed weak explosive activity from the summit, with intervals of steaming. Frequent poor weather obscured the volcano, so the following observations are incomplete to an unknown degree. Cited times are local time, except those of August, which are GMT."
April 6th, some radial ash sprays on the snow were visible at 16:00; April 27th, at 12:10 there was a faint veil-like ash cloud over the summit. In 10 minutes it had disappeared, leaving new ash on the surface of the snow. Also observed was a black streak extending 5-10 km down the NW flank form the summit to about 300 m a.s.l.; April 30th, ash on the snow surface, more apparent than when visible on the 29th (Shackelford, 1978).
May 14th, dark ash visible on the cone; May 16th, ash on snow, May 20th, the NE flank had an extensive ash cover between 1600 and 2500 m a.s.l (Shackelford, 1978).
June 3rd, ash on snow (?); June 4th, occasional ash eruptions were noted between 09:00 and 21:00. The visible flanks were about 70% ash-covered; June 10th, at 15:30 there were intermittent black smoke emissions. Although no longer erupting at 21:00, Shishaldin's upper 600 m were mantled with ash; June 22nd, ash on NE flank over the snow surface; June 27th, light to heavy ash cover on the cone above about 1500 m a.s.l (Shackelford, 1978).
July 6th, between 14:00 and 22:00 dark ash was observed falling on the N flank; July 8th, smoke and ash eruptions were visible during the period 22:00 to 23:00 (Shackelford, 1978).
August 4th, an intensification of the steam emission began after 02:00, becoming 'smoke' after 16:15. There was no observation of a new ash-fall however. By the 30th an estimated 90% of the ash had been blown off Shishaldin (Shackelford, 1978).
September 27th there was a 1 minute projection of a jet of incandescent gas which recurved to the S; September 28th, observations at 06:50 showed the volcano to be occasionally erupting ash clouds (Shackelford, 1978).
October 24th, during the period 16:05 to 17:30 there were puffs of dense smoke observed, with intervals of approximately 5 minutes between puffs, which moved (were blown?) downhill some 100 m down the E flank (Shackelford, 1978).
According to the Smithsonian Institution (1976), Shishaldin continued to steam throughout November, 1976.
In February, 1977, ash emission from Shishaldin was observed on February 14 or 15, and on the 27th, by Peninsula Airways pilots (Smithsonian Institution, 1977).