Report on Shishaldin (United States) — October 1993
Bulletin of the Global Volcanism Network, vol. 18, no. 10 (October 1993)
Managing Editor: Edward Venzke.
Shishaldin (United States) Steam plume observed rising to 1,800 m above the summit
Please cite this report as:
Global Volcanism Program, 1993. Report on Shishaldin (United States) (Venzke, E., ed.). Bulletin of the Global Volcanism Network, 18:10. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199310-311360
54.756°N, 163.97°W; summit elev. 2857 m
All times are local (unless otherwise noted)
A steam plume up to 1,800 m above the volcano was reported by pilots on 28 October. That same day, observers from Izembeck National Wildlife Refuge reported a steam-and-ash plume that rose to 1,200 m above the summit and drifted SE.
Geological Summary. The symmetrical glacier-covered Shishaldin is the highest and one of the most active volcanoes of the Aleutian Islands. It is the westernmost of three large stratovolcanoes in the eastern half of Unimak Island. The Aleuts named the volcano Sisquk, meaning "mountain which points the way when I am lost." Constructed atop an older glacially dissected edifice, it is largely basaltic in composition. Remnants of an older ancestral volcano are exposed on the W and NE sides at 1,500-1,800 m elevation. There are over two dozen pyroclastic cones on its NW flank, which is blanketed by massive aa lava flows. Frequent explosive activity, primarily consisting of Strombolian ash eruptions from the small summit crater, but sometimes producing lava flows, has been recorded since the 18th century. A steam plume often rises from the summit crater.
Information Contacts: Alaska Volcano Observatory.