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Report on Makushin (United States) — January 1994


Makushin

Bulletin of the Global Volcanism Network, vol. 19, no. 1 (January 1994)
Managing Editor: Richard Wunderman.

Makushin (United States) Storm causes false eruption reports; sulfur smell 25 km E

Please cite this report as:

Global Volcanism Program, 1994. Report on Makushin (United States) (Wunderman, R., ed.). Bulletin of the Global Volcanism Network, 19:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199401-311310



Makushin

United States

53.891°N, 166.923°W; summit elev. 1800 m

All times are local (unless otherwise noted)


"Reports of possible eruptive activity . . . 22-23 January reflected a combination of intense lightning near the volcano and a strong sulfur odor detected in Dutch Harbor, 25 km E. The lightning was apparently associated with the passing of a strong storm front, and winds were blowing directly toward Dutch Harbor.

Geological Summary. The ice-covered Makushin volcano on northern Unalaska Island west of the City of Unalaska is capped by a 2.5-km-wide caldera. Its broad, dome-like structure contrasts with the steep-sided profiles of most other Aleutian stratovolcanoes. Much of the edifice was formed during the Pleistocene, but the caldera (which formed about 8,000 years ago), Sugarloaf cone on the ENE flank, and a cluster of about a dozen explosion pits and cinder cones at Point Kadin on the WNW flank, are of Holocene age. A broad band of NE-SW-trending vents cuts across the volcano. The composite Pakushin cone, with multiple summit craters, lies 8 km SW. Frequent explosive eruptions have occurred during the past 4,000 years, sometimes accompanied by pyroclastic flows and surges. Geothermal areas are found in the summit caldera and on the SE and E flanks. Small-to-moderate explosive eruptions have been recorded since 1786.

Information Contacts: AVO.