File:Shishaldin Volcano with white steam plume (afternoon, 15 October 2023) (Aleutian Arc, Alaska, USA) 2.jpg

English: (still image from the Brown Peak web camera on Unimak Island, Alaska)

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Shishaldin Volcano is a subduction zone stratovolcano on Unimak Island in the Aleutian Islands of Alaska. Minor lava eruptions in the summit crater started on 12 July 2023. Twelve episodes of explosive ash eruptions have occurred since then, on 14 July, 15 July, 18 July, 22-23 July, 25-26 July, 4 August, 14-15 August, 25 August, 5 September, 15 September, 25 September, and 3 October 2023. Seen here is Shishaldin with a prominent white steam plume. It is likely the result of snow, ice, and meltwater vaporizing upon contact with hot volcanic rocks and fresh lava in the summit area.

The Aleutian Arc is a subduction zone formed as the Pacific Plate dives underneath the North American Plate (this area is sometimes called the Bering Plate). The diving plate in subduction zones releases water at depth, which causes partial melting of overlying mantle rocks. The low-density melt rises and eventually reaches the surface, forming volcanoes. All subduction zones have volcanoes and frequent seismicity. Volcanoes in such settings tend to have explosive ash eruptions. Rocks and tephra deposits at subduction zone volcanoes are usually intermediate in composition - typically andesitic to dacitic.

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Info. at: en.wikipedia.org/wiki/Mount_Shishaldin and

en.wikipedia.org/wiki/Aleutian_Arc