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Report on Akutan (United States) — October 1978


Scientific Event Alert Network Bulletin, vol. 3, no. 10 (October 1978)
Managing Editor: David Squires.

Akutan (United States) Strombolian activity and possible lava flow

Please cite this report as:

Global Volcanism Program, 1978. Report on Akutan (United States) (Squires, D., ed.). Scientific Event Alert Network Bulletin, 3:10. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN197810-311320


United States

54.134°N, 165.986°W; summit elev. 1303 m

All times are local (unless otherwise noted)

Akutan began to erupt in late September 1978. Airline pilots reported incandescent fragments, some "as big as a car," rising about 100 m above the crater. The USCG Cutter Morgenthau passed N of Akutan during the evening of 6 October. Crew members observed incandescent tephra ejection from the summit and glow reflecting upward onto an eruption column. A deep red glow about 1 km long, which appeared to be a lava flow, moved down the flanks.

Geological Summary. Akutan contains a 2-km-wide caldera with a large cinder cone in the NE part of the caldera that has been the source of frequent explosive eruptions and occasional lava effusion that covers the caldera floor. 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 1,600 years ago and contains at least three lakes. 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: M. Compton, USCGC Morgenthau; D. Hoadley, Reeve Aleutian Airways; J. Kienle, Univ. of Alaska.