Capital
Spurr
Great Sitkin
Legend
✕
Red (Warning) | |
Orange (Watch) | |
Yellow (Advisory) | |
Green (Normal) | |
Uninstrumented | |
Community | |
Webcam | |
Instrument | |
Earthquake Magnitude | |
0
| |
Earthquake Age | |
Last 2 Hours | |
Last 2 Days | |
Last 1 Week |
Facts
- Official Name: Capital Mountain
- Seismically Monitored: No
- Color Code: UNASSIGNED
- Alert Level: UNASSIGNED
- Elevation: 2356m (7729ft)
- Latitude: 62.4238
- Longitude: -144.1127
- Smithsonian VNum:
- Pronunciation:
-
Nearby Towns:
- Slana 20 mi (32 km) NE
- Chistochina 20 mi (32 km) NW
- Mentasta Lake 37 mi (59 km) NE
- Gakona 39 mi (63 km) SW
- Gulkana 42 mi (68 km) SW
Distance from Anchorage: 206 mi (332 km)
Description
From Wood and Kienle (1990) [1] : "Capital Mountain is a relatively small andesitic shield volcano with a roughly circular summit caldera 4 km in diameter. The shield consists chiefly of lava flows and subordinate volcaniclastic rocks that dip 3 to 25 degrees away from the summit area. The caldera, apparently of non-explosive origin, is filled with thick, flat-lying flows. Talus, flow breccias, and pillow lavas occur locally between the caldera wall and intracaldera flows. A prominent andesite plug, 100 m high, marks the general center of an area of post-caldera-fill activity and is the locus of a spectacular radial dike swarm. Shield and intracaldera lavas are chiefly hypersthene andesite, but shield lavas range in composition from basalt to dacite. Dikes are also chiefly andesite; one prominent rhyolite dike originating from a small rhyolite laccolith extends almost completely across the volcano."Name Origin
The name Capital Mountain was recorded by T.G. Gerdine as a local name (Mendenhall, 1905; Orth, 1971).
References Cited
[1] Volcanoes of North America: United States and Canada, 1990
Wood, C. A., and Kienle, Juergen, (eds.), 1990, Volcanoes of North America: United States and Canada: New York, Cambridge University Press, 354 p.Reported Activity
Modern Eruptions
1 Event Date(s)
Past Activity Legend:
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Eruption |
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Questionable eruption |
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Non-eruptive activity |
Showing 1 - 2 of 2
Map Images
Map References
Geologic map of the Wrangell-Saint Elias National Park and Preserve, Alaska, 2006
Richter, D.H., Preller, C.C., Labay, K.A., and Shew, N.B., compilers, 2006, Geologic map of the Wrangell-Saint Elias National Park and Preserve, Alaska: U.S. Geological Survey Scientific Investigations Map 2877, 15 p., 1 plate, scale 1:350,000, available at http://pubs.usgs.gov/sim/2006/2877/ .
Volcanoes of Alaska, 1998
Nye, C. J., Queen, Katherine, and McCarthy, A. M., 1998, Volcanoes of Alaska: Alaska Division of Geological & Geophysical Surveys Information Circular IC 0038, unpaged, 1 sheet, scale 1:4,000,000, available at http://www.dggs.dnr.state.ak.us/pubs/pubs?reqtype=citation&ID=7043 .

Volcanoes of Alaska, 1995
Alaska Division of Geological & Geophysical Surveys, 1995, Volcanoes of Alaska: Alaska Division of Geological & Geophysical Surveys Information Circular IC 0038, unpaged, 1 sheet, scale 1:4,000,000.
Geologic map of the Gulkana B-1 quadrangle, south-central Alaska, 1989
Richter, D. H., Ratte, J. C., Schmoll, H. R., Leeman, W. P., Smith, J. G., and Yehle, L. A., 1989, Geologic map of the Gulkana B-1 quadrangle, south-central Alaska: U.S. Geological Survey Geological Quadrangle Map GQ 1655, 1 p., 1 sheet, scale 1:63,360.
Map showing distribution, composition, and age of Late Cenozoic volcanic centers in Alaska, 1986
Luedke, R. G., and Smith, R. L., 1986, Map showing distribution, composition, and age of Late Cenozoic volcanic centers in Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I 1091-F, unpaged, 3 sheets, scale 1:1,000,000.
Geologic map of the Nabesna quadrangle, Alaska, 1976
Richter, D. H., 1976, Geologic map of the Nabesna quadrangle, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I 0932, unpaged, 1 plate, scale 1:250,000.
References
Geologic database of information on volcanoes in Alaska (GeoDIVA), 2022
Cameron, C.E., Crass, S.W., and AVO Staff, eds, 2022, Geologic database of information on volcanoes in Alaska (GeoDIVA): Alaska Division of Geologic and Geophysical Surveys Digital Data Series 20, https://doi.org/10.14509/geodiva, https://doi.org/10.14509/30901.
Preliminary database of Quaternary vents in Alaska, 2014
Cameron, C.E., and Nye, C.J., 2014, Preliminary database of Quaternary vents in Alaska: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication 153, 11 p., doi:10.14509/27357 .
Ahtna Place Names Lists, 2008
Kari, James, 2008, Ahtna Place Names Lists: Fairbanks, Alaska, Alaska Native Language Center, 156 p.
Geologic map of the Wrangell-Saint Elias National Park and Preserve, Alaska, 2006
Richter, D.H., Preller, C.C., Labay, K.A., and Shew, N.B., compilers, 2006, Geologic map of the Wrangell-Saint Elias National Park and Preserve, Alaska: U.S. Geological Survey Scientific Investigations Map 2877, 15 p., 1 plate, scale 1:350,000, available at http://pubs.usgs.gov/sim/2006/2877/ .
Bibliography of information on Alaska volcanoes, 2003
Cameron, C. E., Triplehorn, J. H., and Robar, C. L., 2003, Bibliography of information on Alaska volcanoes: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication MP 131, 1 CD-ROM.
Hard Copy held by AVO at FBKS - CEC file cabinet
Volcanoes of Alaska, 1998
Nye, C. J., Queen, Katherine, and McCarthy, A. M., 1998, Volcanoes of Alaska: Alaska Division of Geological & Geophysical Surveys Information Circular IC 0038, unpaged, 1 sheet, scale 1:4,000,000, available at http://www.dggs.dnr.state.ak.us/pubs/pubs?reqtype=citation&ID=7043 .

Guide to the volcanoes of the western Wrangell Mountains, Alaska - Wrangell-St. Elias National Park and Preserve, 1995
Richter, D. H., Rosenkrans, D. S., and Steigerwald, M. J., 1995, Guide to the volcanoes of the western Wrangell Mountains, Alaska - Wrangell-St. Elias National Park and Preserve: U.S. Geological Survey Bulletin 2072, 31 p.

Volcanoes of Alaska, 1995
Alaska Division of Geological & Geophysical Surveys, 1995, Volcanoes of Alaska: Alaska Division of Geological & Geophysical Surveys Information Circular IC 0038, unpaged, 1 sheet, scale 1:4,000,000.
Quaternary volcanism in the Alaska Peninsula and Wrangell Mountains, Alaska, 1994
Miller, T. P., and Richter, D. H., 1994, Quaternary volcanism in the Alaska Peninsula and Wrangell Mountains, Alaska: in Plafker, George, Jones, D. L., and Berg, H. C., (eds.), The Geology of Alaska, Geological Society of America The Geology of North America series v. G-1, p. 759-779.
Hard Copy held by AVO at FBKS - CEC file cabinet
Age and progression of volcanism, Wrangell volcanic field, Alaska, 1990
Richter, D. H., Smith, J. G., Lanphere, M. A., Dalrymple, G. B., Reed, B. L., and Shew, N., 1990, Age and progression of volcanism, Wrangell volcanic field, Alaska: Bulletin of Volcanology, v. 53, n. 1, p. 29-44.

Volcanoes of North America: United States and Canada, 1990
Wood, C. A., and Kienle, Juergen, (eds.), 1990, Volcanoes of North America: United States and Canada: New York, Cambridge University Press, 354 p.
Hard Copy held by AVO at FBKS - CEC shelf
Geologic map of the Gulkana B-1 quadrangle, south-central Alaska, 1989
Richter, D. H., Ratte, J. C., Schmoll, H. R., Leeman, W. P., Smith, J. G., and Yehle, L. A., 1989, Geologic map of the Gulkana B-1 quadrangle, south-central Alaska: U.S. Geological Survey Geological Quadrangle Map GQ 1655, 1 p., 1 sheet, scale 1:63,360.
Map showing distribution, composition, and age of Late Cenozoic volcanic centers in Alaska, 1986
Luedke, R. G., and Smith, R. L., 1986, Map showing distribution, composition, and age of Late Cenozoic volcanic centers in Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I 1091-F, unpaged, 3 sheets, scale 1:1,000,000.
Shield volcanoes in the Wrangell Mountains, Alaska, 1984
Richter, D. H., Smith, J. G., Ratte, J. C., and Leeman, W. P., 1984, Shield volcanoes in the Wrangell Mountains, Alaska: in Reed, K. M. and Bartsch-Winkler, Susan, (eds.), The United States Geological Survey in Alaska: accomplishments during 1982, U.S. Geological Survey Circular C 0939, p. 71-75.
Hard Copy held by AVO at FBKS - CEC shelf
Geologic map of the Nabesna quadrangle, Alaska, 1976
Richter, D. H., 1976, Geologic map of the Nabesna quadrangle, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I 0932, unpaged, 1 plate, scale 1:250,000.
Before an eruption
Ashfall & Preparedness Information
- Ashfall impacts & preparedness (US Geological Survey)
- Volcanic health hazards & impacts (International Volcanic Health Hazards Network)
- Ash Alert! Pamphlet (AK Division of Homeland Security & Emergency Management)
- Volcanic Ashfall (AK Department of Environmental Conservation, Division of Air Quality)