• Official Name: Westdahl Peak
  • Seismically Monitored: No
  • Color Code: UNASSIGNED
  • Alert Level: UNASSIGNED
  • Elevation: 1560m (5118ft)
  • Latitude: 54.5171
  • Longitude: -164.6476
  • Smithsonian VNum: 311340
  • Nearby Towns:
    • Akutan 52 mi (84 km) SW
    • False Pass 55 mi (88 km) NE
    • Pauloff Harbor 78 mi (126 km) SE
    • Unalaska 88 mi (142 km) SW
    • Cold Bay 89 mi (144 km) NE
  • Subfeatures:
    • Pogromni
    • Faris Peak
    • Pogromni's Sister


From Miller and others (1998) [1] : "Westdahl Peak, including nearby Faris Peak and Pogromni volcano, is located on a gently sloping plateau (mean elevation 1220 m) that may represent the surface of a truncated ancestral cone. Westdahl Peak is about 18 km in diameter at the base.
"The size of the postulated ancestral cone is about 19 x 30 km at sea level, making it one of the largest volcanoes in the Aleutian Islands be it a stratovolcano or a shield. The entire ancestral cone has been extensively dissected by erosion, with the northeast-facing slopes steeper and of greater relief than the other slopes.
"Based on the degree of erosional dissection, most of the postulated stratovolcano must have formed before early post-glacial time. Pogromni Volcano is moderately dissected and has broad valleys that have probably been glacially eroded. Such glacial erosion could have occurred during neoglaciation beginning about 3000 years ago (Black, 1974 [2] , table 1), although one or two thousand years seem inadequate to account for the degree of dissection. Pogromni volcano was probably active by latest Pleistocene time, which implies that truncation of the ancestral stratovolcano must have occurred earlier."

Name Origin

Westdahl Peak was named in 1902 by O.H. Tittmann, for Ferdinand Westdahl of the U.S. Coast and Geodetic Survey, who determined its geographic position in 1901 (Orth, 1971).

References Cited

[1] Catalog of the historically active volcanoes of Alaska, 1998

Miller, T. P., McGimsey, R. G., Richter, D. H., Riehle, J. R., Nye, C. J., Yount, M. E., and Dumoulin, J. A., 1998, Catalog of the historically active volcanoes of Alaska: U.S. Geological Survey Open-File Report 98-0582, 104 p.

[2] Late-Quaternary sea level changes, Umnak Island, Aleutians: their effects on ancient Aleuts and their causes, 1974

Black, R. F., 1974, Late-Quaternary sea level changes, Umnak Island, Aleutians: their effects on ancient Aleuts and their causes: Quaternary Research, v. 4, n. 3, p. 264-281.

Current Activity

February 7, 2024, 10:42 am

The Alaska Volcano Observatory (AVO) has experienced the failure of seismic monitoring equipment at Westdahl Volcano and the remaining instrumentation is insufficient to establish that the volcano is at a typical background level. It is not possible to repair this equipment until next summer's field season. As a result, AVO is unable to (1) assess whether this volcano may be building towards an eruption and (2) quickly confirm or dismiss reports of activity.

The Aviation Color Code and Volcano Alert Level are changed to UNASSIGNED/UNASSIGNED because this volcano is no longer seismically monitored at adequate levels. As at other volcanoes without real-time seismic networks, AVO will continue to use satellite data, regional seismic, infrasound, and lightning networks, and reports from pilots and ground observers to detect signs of eruptive activity.

Color Code Timeline


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