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Stepovak Bay Group

Volcanic field · United States · 1633m

Stepovak Bay 2 is part of the Stepovak Bay Group on the western Alaska Peninsula. The group is located along a NE-trending ridge, seen here in this 14 September 2018 Sentinel-2 satellite image (N is at the top), which is approximately 14 km across. Several of the volcanoes have produced debris flows and lava flows in the Holocene.
Stepovak Bay 2 is part of the Stepovak Bay Group on the western Alaska Peninsula. The group is located along a NE-trending ridge, seen here in this 14 September 2018 Sentinel-2 satellite image (N is at the top), which is approximately 14 km across. Several of the volcanoes have produced debris flows and lava flows in the Holocene. · Photo: Satellite image courtesy of Copernicus Sentinel Data, 2018.
Type
Volcanic field
Country
United States
Region
North America Volcanic Regions / Aleutian Ridge Volcanic Arc
Elevation
1633m
Coordinates
55.917, -160.017
Last eruption
Unknown
Tectonic setting
Subduction zone / Continental crust (> 25 km)
Landform
Cluster
Geological summary

The Stepovak Bay Group is a chain of four cones, extending over a distance of 18 km, just SW of Kupreanof volcano. Stepovak Bay 2 is a cinder cone with a Holocene andesitic lava flow extending initially to the NE, then SE. The Stepovak Bay 3 cinder cone has a thick Holocene lava flow that originated from an ice-filled 300-m-wide crater and entered the same valley as the lava flow from Stepovak Bay 2 (Wilson, 1989); however, Wilson (in Wood and Kienle, 1990) noted uncertainty about this being Holocene activity. Stepovak Bay 4 is a small stratovolcano with Holocene debris flows or block-and-ash flows, and a fumarole has been observed. Stepovak Bay 1, the southwesternmost of the chain is Pleistocene, with K-Ar dates of about 0.53 and 0.4 million years (Wilson, 1989).

Eruption history

Detailed timeline

No eruption records available.

External links

⚠ For reference only. Not for emergency response.