Report on Akutan (United States) — April 1988
Scientific Event Alert Network Bulletin, vol. 13, no. 4 (April 1988)
Managing Editor: Lindsay McClelland.
Akutan (United States) Small ash eruptions
Please cite this report as:
Global Volcanism Program, 1988. Report on Akutan (United States). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 13:4. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198804-311320.
54.134°N, 165.986°W; summit elev. 1303 m
All times are local (unless otherwise noted)
Small ash eruptions from the summit cinder cone were observed in March and April (table 2)....
|Date||Time||Activity [with observers]|
|26 Mar 1988||p.m.||Stinging eyes, strong sulfur smell, minor ashfall noted on snow at Akutan village, 12.5 km E of the volcano [DM].|
|01 Apr 1988||--||Gray ash deposits visible near the summit when weather cleared [DM].|
|10 Apr 1988||1305||Black ash rose about 450-600 m above the summit and drifted NW [TM].|
|14 Apr 1988||1003||Steam and ash rose through clouds to 2,960 m altitude (summit elevation, 1,303 m); new ash deposit, 1 km wide later that day, extended 9 km SE to the coast [GT, NS].|
|14 Apr 1988||1000-1500||Three to four eruptions observed; black to gray ash rose 100 m and drifted W; ash deposits visible on mountains W and SW of Akutan village [AJ, DM].|
|17 Apr 1988||0930||1,200-m black ash cloud ejected, developed a mushroom shape, and blew towards Akutan village, where about 1 mm fell; ashfall looked thicker to the S [AJ].|
|19 Apr 1988||1254||Ash emission seen but visibility poor; strong sulfur smell [TM].|
|20 Apr 1988||a.m.||Narrow but mushrooming black ash plume rose to 600 m height in 2 minutes at 0820; similar eruption to 900 m height at 0900; three more dark gray plumes ejected, to no more than 1,200 m, at 0920, 0930, and 1000; all drifted NE [AJ, DM].|
|21 Apr 1988||0749||Narrow mushrooming plume rose 1,500 m and drifted NE [AJ].|
|late April 1988||--||Narrow dark ash deposit extended N of the volcano to the coast [NS].|
Geologic Background. One of the most active volcanoes of the Aleutian arc, Akutan contains 2-km-wide caldera with an active intracaldera cone. An older, largely buried caldera was formed during the late Pleistocene or early Holocene. Two volcanic centers are located on the NW flank. Lava Peak is of Pleistocene age, and a cinder cone lower on the flank produced a lava flow in 1852 that extended the shoreline of the island and forms Lava Point. The 60-365 m deep younger caldera was formed during a major explosive eruption about 1600 years ago and contains at least three lakes. The currently active large cinder cone in the NE part of the caldera has been the source of frequent explosive eruptions with occasional lava effusion that blankets the caldera floor. A lava flow in 1978 traveled through a narrow breach in the north caldera rim almost to the coast. Fumaroles occur at the base of the caldera cinder cone, and hot springs are located NE of the caldera at the head of Hot Springs Bay valley and along the shores of Hot Springs Bay.
Information Contacts: J. Reeder, ADGGS.