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  • United States
  • Alaska
  • Stratovolcano
  • 1997 CE
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 52.5°N
  • 171.252°W

  • 1066 m
    3496 ft

  • 311190
  • Latitude
  • Longitude

  • Summit

  • Volcano

The Global Volcanism Program has no activity reports for Amukta.

The Global Volcanism Program has no Weekly Reports available for Amukta.

Index of Monthly Reports

Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

08/1987 (SEAN 12:08) Possible source of 10.6-km cloud

09/1996 (BGVN 21:09) Small ash plumes observed in mid-September

09/1997 (BGVN 22:09) Ash puff on 2 March rises to just above the summit

Contents of Monthly Reports

All information contained in these reports is preliminary and subject to change.

All times are local (= UTC - 9 hours)

08/1987 (SEAN 12:08) Possible source of 10.6-km cloud

At about 1000 on 28 August pilots Charles Kozler, Wayne Russell, and George Wooliver (Reeve Aleutian Airways) reported an eruption plume reaching 10.5 km altitude in the vicinity of Amukta, drifting WNW. The FAA issued a NOTAM warning pilots to stay 25 miles [40 km] from Amukta Island. Heavy weather clouds covered Amukta Island so its activity could not be directly observed. Mt. Cleveland, 100 km ENE, was apparently active that same morning and winds were blowing in the direction of Amukta (see Mt. Cleveland 12:08). The origin of the large cloud remains both uncertain and controversial at the time of this report.

On 4 September Wooliver observed a small dark ash plume rising at least 300 m above the summit of Amukta then drifting as much as 1 km NW. Only the NW flank was visible because of cloud cover. His observations were made from 9,750 m altitude from nearly 120 km N. Wooliver has flown in the Aleutian Islands since the 1950's and is experienced at observing eruptions.

Amukta's last known eruptive activity was on 12 July 1984 (BVE, no. 24). Harold Wilson (Peninsula Airways) notes that normal activity . . . is continuous minor steam emission from several small vents just inside the summit crater rim.

Information Contacts: T. Miller, USGS Anchorage; J. Reeder, ADGGS.

9/1996 (BGVN 21:09) Small ash plumes observed in mid-September

On 18 September AVO received a pilot report of a small ash plume above Amukta. An Alaska Airlines pilot noted black and gray ash clouds rising ~300 m above the summit crater during overflights on 17 and 18 September. The ash plumes extended ~16 km S over the Pacific Ocean before dissipating. No plume was visible on satellite imagery.

Information Contacts: Alaska Volcano Observatory (AVO); NOAA/NESDIS Satellite Analysis Branch, Room 401, 5200 Auth Road, Camp Springs, MD 20746, USA.

09/1997 (BGVN 22:09) Ash puff on 2 March rises to just above the summit

On 2 March a pilot reported a small eruption at Amukta volcano in the central Aleutian Islands. Ash barely clearing the top of the volcano was reported.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of a) U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL:, b) Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and c) Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA.

The symmetrical Amukta stratovolcano lies in the central Aleutians SW of Chagulak Island and is the westernmost of the Islands of the Four Mountains group. Amukta was constructed at the northern side of an arcuate caldera-like feature that is open to the sea along the southern coast of the 8-km-wide Amukta Island. The 1066-m-high stratovolcano overlies a broad shield volcano and is topped by a 400-m-wide crater. A cinder cone is located near the NE coast. Amukta has had several eruptions in historical time from both summit and flank vents.

Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1997 Mar 3 Unknown Confirmed 1 Historical Observations
1996 Sep 17 1996 Sep 18 Confirmed 1 Historical Observations
1987 Sep 4 (?) Unknown Confirmed 1 Historical Observations
1963 Feb 13 Unknown Confirmed 3 Historical Observations
1878 Unknown Confirmed   Historical Observations
[ 1876 ] [ Unknown ] Uncertain    
1786 Jun 1791 Confirmed 3 Historical Observations
[ 1770 ] [ Unknown ] Uncertain    

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Amuchta | Amarchta
Symmetrical snow-capped Amukta stratovolcano in the central Aleutian Islands is located at the northern side of an arcuate caldera-like feature along the coast of the 8-km-wide island of the same name. The 1066-m-high stratovolcano overlies a broad shield volcano and is topped by a 400-m-wide crater. Amukta has had several eruptions since the late 18th century from both summit and flank vents.

Photo by U.S. Fish and Wildlife Service, 1972 (courtesy of Alaska Volcano Observatory).
The ruggedly dissected eastern side of the Chagulak volcano rises to 1142 m above a sea of clouds. Chagulak is the summit of a small, unstudied stratovolcano NE of Amukta, the flat-topped volcano in the left distance. The two volcanoes coalesce at depth although they are separated by 7 km of ocean. No historical eruptions have been recorded from Chagulak volcano, and its age is not precisely known.

Photo by Fred Deines, 1992 (U.S. Fish and Wildlife Service).

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title.

Coats R R, 1950. Volcanic activity in the Aleutian Arc. U S Geol Surv Bull, 974-B: 35-47.

Henning R A, Rosenthal C H, Olds B, Reading E (eds), 1976. Alaska's volcanoes, northern link in the ring of fire. Alaska Geog, 4: 1-88.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior..

Miller T P, McGimsey R G, Richter D H, Riehle J R, Nye C J, Yount M E, Dumoulin J A, 1998. Catalogue of the historically active volcanoes of Alaska. U S Geol Surv Open-File Rpt, 98-582: 1-104.

Motyka R J, Liss S A, Nye C J, Moorman M A, 1993. Geothermal resources of the Aleutian arc. Alaska Div Geol Geophys Surv, Prof Rpt, no 114, 17 p and 4 map sheets.

Smith R L, Shaw H R, Luedke R G, Russell S L, 1978. Comprehensive tables giving physical data and thermal energy estimates for young igneous systems of the United States. U S Geol Surv Open-File Rpt, 78-925: 1-25.

Wood C A, Kienle J (eds), 1990. Volcanoes of North America. Cambridge, England: Cambridge Univ Press, 354 p.

Volcano Types

Pyroclastic cone

Tectonic Setting

Subduction zone
Intermediate crust (15-25 km)

Rock Types

Andesite / Basaltic Andesite


Within 5 km
Within 10 km
Within 30 km
Within 100 km

Affiliated Databases

Large Eruptions of Amukta Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
WOVOdat WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
EarthChem EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.