Wide Bay cone


  • Seismically Monitored: No
  • Color Code: UNASSIGNED
  • Alert Level: UNASSIGNED
  • Elevation: 640m (2099ft)
  • Latitude: 53.9611
  • Longitude: -166.615
  • Smithsonian VNum:
  • Pronunciation:
  • Nearby Towns:
    • Unalaska 7 mi (11 km) SE
    • Akutan 36 mi (58 km) NE
    • Nikolski 117 mi (188 km) SW
    • False Pass 143 mi (230 km) NE
    • Pauloff Harbor 162 mi (260 km) NE


From Miller and others (1998) [1] : "Wide Bay cone, a small symmetric cone with an oval summit crater, occupies the northwest edge of Unalaska Bay." Wide Bay cone is Holocene in age, and is considered to represent a magmatic system separate from that of Makushin Volcano (Nye, personal commun., 2007). From McConnell and others (1998) [2] : "Basaltic tephra and lava flows form the monogenetic Wide Bay Cone near Eider Point, the easternmost volcano of the Makushin volcanic field. Both tephra and lava flows are dominated by up to 20 vol.% of large, single phenocrysts and glomerocrysts of clinopyroxene. The clinopyroxene is zoned and may reach 4 mm in diameter. Additional important phenocryst phases include plagioclase (15 to 19 vol.%), olivine (1 to 5 vol.%), and minor magnetite in a microlite-rich, sideromelane groundmass. Lowermost flows at the base of the cone are glacially striated although the cone remains well shaped with the summit vent depression preserved."

Name Origin

"Wide Bay cone" is an informal name, after the nearby Wide Bay.

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] Geologic map of the Makushin volcanic field, Unalaska Island, Alaska, 1998

McConnell, V. S., Beget, J. E., Roach, A. L., Bean, K. W., and Nye, C. J., 1998, Geologic map of the Makushin volcanic field, Unalaska Island, Alaska: Alaska Division of Geological & Geophysical Surveys Report of Investigation 97-20, unpaged, 2 sheets, scale 1:63,360.

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