Moffett
Spurr
Great Sitkin
Legend
✕
 | Red (Warning) |
| Orange (Watch) |
| Yellow (Advisory) |
 | Green (Normal) |
| Uninstrumented |
 | Community |
 | Webcam |
 | Instrument |
| Earthquake Magnitude | |
|
0
7+
| |
| Earthquake Age | |
|
Last 2 Hours |
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Last 2 Days |
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Last 1 Week |
Facts
- Official Name: Mount Moffett
- Seismically Monitored: No
- Color Code: UNASSIGNED
- Alert Level: UNASSIGNED
- Elevation: 1196m (3923ft)
- Latitude: 51.937
- Longitude: -176.741
- Smithsonian VNum: 311111
- Pronunciation:
-
Nearby Towns:
- Adak 7 mi (11 km) SE
- Atka 109 mi (176 km) NE
- Nikolski 339 mi (545 km) NE
- Shemya Station 390 mi (627 km) NW
- Attu Station 427 mi (688 km) NW
Distance from Anchorage: 1193 mi (1920 km)
-
Subfeatures:
- Moffett parasitic cone
Description
From Wood and Kienle (1990) [1] : "Adak is a large Tertiary island in the central Aleutians with a small (~40 cubic km) volcanic center at its northern extremity. Kanaga lies to the west and Great Sitkin to the east. Because of its easy access, Adak is certainly the most frequently visited and sampled island in the Aleutians. Andrew Bay (~350 m, oldest), Mount Moffet (1,200 m), and Mount Adagdak (650 m) volcanoes have produced essentially all the Recent volcanic material. Only the erosional vestiges of Andrew Bay volcano remain (now filled by Andrew Bay and Lake); it was apparently obliterated by caldera formation, encroachment of the sea, and glaciation. Heavily glaciated, Mount Moffet consists of principally of thick andesite flows, flank domes, and a substantial parasitic cone of many thin basalt flows. The scoriaceous, blocky dome on the outward south flank of Mount Moffet may be one of the youngest volcanic features of this center. Mount Adagdak is a model composite cone with a distinct lower shield of one or two basalt flows and interbedded scoria. At ~350 m the small stratovolcano begins, consisting mainly of volcaniclastic debris and an occasionally thin, fragmentary andesitic flow. The summit crater, with a well-defined south rim, is occupied by a hornblende andesite plug; in places it has vertical, smooth walls peppered with indigenous xenoliths. At one time this plug may have been partly a Pelean spine, large blocks of which are scattered across the shield. A northwesterly directed explosion and ash flow may have strongly breached the summit crater prior to the vent-filling event. A late stage basaltic dome lies on the southeast flank."Although Moffet and Adagdak are certainly volcanoes, when compared to large Aleutian volcanoes, both vents represent small, almost futile outpourings. This is perhaps reflected in the heterogeneous nature and composition of the erupted materials. Mafic, olivine-rich xenolithic material is common in a thick andesite flow on the north shore of Mount Moffet, and also in an apparently phreatic vent on the west shield of Mount Adagdak; gabbroic and dioritic xenoliths are found along the bouldery beach north of Mount Adagdak."
Name Origin
Mount Moffett was named by the U.S. Navy Hydrographic Office in 1936, after Rear-Admiral William Adger Moffett (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
3 Event Date(s)
Past Activity Legend:
 |
Eruption |
 |
Questionable eruption |
 |
Non-eruptive activity |
Map Images
By:
U.S. Geological Survey
Topographic shaded relief map of Adagdak, Moffet, and Andrew Bay volcanoes, Alaska.
Topographic shaded relief map of Adagdak, Moffet, and Andrew Bay volcanoes, Alaska.
By:
U.S. Geological Survey
Topographic map of Mount Moffet and Adagdak, and showing Andrew Bay volcano remnant.
Topographic map of Mount Moffet and Adagdak, and showing Andrew Bay volcano remnant.
By:
Baten, S. K.
Geologic map of northern Adak Island.
Geologic map of northern Adak Island.
Map References
Digital data for the reconnaissance geologic map of the western Aleutian islands, Alaska, 2006
Wilson, F.H., Mohadjer, Solmaz, Labay, K.A., Shew, Nora, and Grey, D.M., 2006, Digital data for the reconnaissance geologic map of the western Aleutian islands, Alaska: U.S. Geological Survey Open-File Report 2006-1302, 1 p., available online at http://pubs.usgs.gov/of/2006/1302/
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 .
Surficial geologic map of northern Adak Island, Alaska, 1995
Waythomas, C. F., 1995, Surficial geologic map of northern Adak Island, Alaska: U.S. Geological Survey Open-File Report 95-0128, 6 p., 1 plate, scale 1:25,000.
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.
Geothermal resources of the Aleutian Arc, 1993
Motyka, R. J., Liss, S. A., Nye, C. J., and Moorman, M. A., 1993, Geothermal resources of the Aleutian Arc: Alaska Division of Geological & Geophysical Surveys Professional Report PR 0114, 17 p., 4 sheets, scale 1:1,000,000.
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.
Geology of southern Adak Island and Kagalaska Island, Alaska, 1959
Fraser, G. D., and Snyder, G. L., 1959, Geology of southern Adak Island and Kagalaska Island, Alaska: in Investigations of Alaskan volcanoes, U.S. Geological Survey Bulletin 1028-M, p. 371-408, 2 sheets, scale 1:125,000.
full-text PDF 4.7 MB
plate 52 PDF 2.6 MB
plate 53 PDF 1.9 MB 
Geology of northern Adak Island, Alaska, 1956
Coats, R. R., 1956, Geology of northern Adak Island, Alaska: in Investigations of Alaskan volcanoes, U.S. Geological Survey Bulletin 1028-C, p. 45-67, 1 sheet, scale 1:50,000.
full-text PDF 831 KB
plate 9 PDF 3.3 MB 
Reconnaissance geology of some western Aleutian Islands, Alaska, 1956
Coats, R. R., 1956, Reconnaissance geology of some western Aleutian Islands, Alaska: in Investigations of Alaskan volcanoes, U.S. Geological Survey Bulletin 1028-E, p. 83-100, 1 sheet, scale unknown.
full-text PDF 4.4 MB
plate 17 PDF 1.6 MB 
Alaskan volcano investigations Report no. 2: Progress of investigations in 1946, 1947
Robinson, G. D., Kennedy, G. C., Waldron, H. H., Byers, F. M. Jr., Hopkins, D. M., Wier, K. L., Fisher, B., Simons, F. S., Mathewson, D. E., and Coats, R. R., 1947, Alaskan volcano investigations Report no. 2: Progress of investigations in 1946: U.S. Geological Survey Alaskan Volcano Investigations Report 0002, 105 p., 8 sheets, scale 1:250,000.
Hard Copy held by AVO at FBKS - CEC shelf
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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)