Makushin

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  • United States
  • Alaska
  • Stratovolcano
  • 1995 CE
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 53.891°N
  • 166.923°W

  • 1800 m
    5904 ft

  • 311310
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

30 May-5 June 2001

Since July 2000 AVO has detected a slight increase in the number of small earthquakes beneath Makushin. The earthquakes generally ranged in depth between 0 and 8 km and were too small to be felt by humans (M0-1.5). The seismic activity was not considered to be an immediate precursor to eruptive activity. Similar fluctuations in earthquake activity have been observed at a number of Aleutian volcanoes that did not result in an eruption. The Concern Color Code remained at Green.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Index of Weekly Reports


2001: May

Weekly Reports


30 May-5 June 2001

Since July 2000 AVO has detected a slight increase in the number of small earthquakes beneath Makushin. The earthquakes generally ranged in depth between 0 and 8 km and were too small to be felt by humans (M0-1.5). The seismic activity was not considered to be an immediate precursor to eruptive activity. Similar fluctuations in earthquake activity have been observed at a number of Aleutian volcanoes that did not result in an eruption. The Concern Color Code remained at Green.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


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.

07/1980 (SEAN 05:07) Recently-ejected tephra; vapor emission

04/1986 (SEAN 11:04) Increased steaming from six summit area vents

06/1986 (SEAN 11:06) Increased steam plume

02/1987 (SEAN 12:02) Small ash eruption; new steam vents

04/1987 (SEAN 12:04) Correction: 2 March ash plume was from Akutan

01/1994 (BGVN 19:01) Storm causes false eruption reports; sulfur smell 25 km E

01/1995 (BGVN 20:01) Small steam-and-ash plume reported by pilots

06/2001 (BGVN 26:06) Slight increase in small earthquakes during July 2000-June 2001


Contents of Monthly Reports

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

All times are local (= UTC - 9 / 8 hours (winter / summer))

07/1980 (SEAN 05:07) Recently-ejected tephra; vapor emission

On 8 July, J. Hauptmann, G. Gunther, and R. [Steuer] visited a seismic station on the E flank and overflew the summit. More than ten roughly circular vents emitted vapor from the summit area, a flat region about 100 m across. The largest vent was about 30 m in diameter, and others were around 10 m across. An H2S odor was detected, but no ash or incandescent material was observed.

About 60 m below the summit on the S flank, an explosion vent had recently ejected tephra ranging in size from ash to blocks, deposited in streaks aligned roughly toward the SE. Some impact craters were present in the deposit area, which extended 30-60 m from the vent.

Information Contacts: J. Hauptmann, G. Gunther, R. Steuer, and S. McNutt, Lamont-Doherty Geological Observatory (LDGO).

04/1986 (SEAN 11:04) Increased steaming from six summit area vents

On 20 December, pilot T. Madsen (Aleutian Air) noticed anomalous amounts of steam rising from six large and closely spaced steam vents just E of the summit. The largest plume was 500-600 m high. No ash was observed in the white plumes. Air temperature at 2,400 m was -6.7°C, warm for that altitude. Steaming remained anomalously vigorous for the next two days before returning to a more normal level. Based on John Reeder's observations . . . since 1979, the summit steam activity is continuous and normally reaches heights of 100 m or slightly less.

Information Contacts: J. Reeder, Alaska Division of Geological and Geophysical Surveys (ADGGS).

06/1986 (SEAN 11:06) Increased steam plume

On 28 April at 0700, James Dickson observed a 450 m vertical steam plume over Makushin that trailed SE for at least 30 km. He detected no ash in the plume.

Information Contacts: J. Reeder, ADGGS.

02/1987 (SEAN 12:02) Small ash eruption; new steam vents

On 2 March between 1700 and 1940, a dark eruption plume rose about 900 m above the volcano and drifted SW [this was actually an eruption from Akutan; see 12:04]. After the eruption a 60-m-high steam plume remained.

An airplane pilot (T. Madsen) noted two fairly large steam vents, which he had not noticed on previous flights, on 29 February and 1 and 2 March.

Information Contacts: J. Reeder, ADGGS.

04/1987 (SEAN 12:04) Correction: 2 March ash plume was from Akutan

The 2 March eruption plume [previously reported] was actually a plume from Akutan. Activity on 2 March was limited to a steam plume containing ash that extended at least 30 km E from the summit. Pilot H. Wilson (Peninsula Airways) observed several steam plumes rising at least 250 m above the summit and drifting at least 3 km WNW. He noted particulate matter, possibly ash, over snow in the summit region.

Information Contacts: J. Reeder, ADGGS; T. Miller, USGS Anchorage; W. Gould, NOAA/NESDIS.

01/1994 (BGVN 19:01) Storm causes false eruption reports; sulfur smell 25 km E

"Reports of possible eruptive activity . . . 22-23 January reflected a combination of intense lightning near the volcano and a strong sulfur odor detected in Dutch Harbor, 25 km E. The lightning was apparently associated with the passing of a strong storm front, and winds were blowing directly toward Dutch Harbor.

Information Contacts: AVO.

01/1995 (BGVN 20:01) Small steam-and-ash plume reported by pilots

A small steam-and-ash cloud observed by Coast Guard C-130 pilots at 1246 on 30 January reportedly rose to ~2,400 m altitude and was carried NE from the volcano. Several pilots reported a diminishing light brown ash plume during the next hour, and all activity apparently subsided shortly thereafter. A satellite image recorded at 1345 showed no sign of eruptive activity, but the NWS issued a SIGMET that ran until 1700.

Information Contacts: Alaska Volcano Observatory.

06/2001 (BGVN 26:06) Slight increase in small earthquakes during July 2000-June 2001

The last eruption of Makushin occurred on 30 January 1995 and produced an ash cloud that rose to ~2.5 km altitude (BGVN 20:01). The Alaska Volcano Observatory reported that during July 2000 to June 2001 they detected a slight increase in the number of small earthquakes beneath Makushin. The volcano is located 25 km W of the city of Unalaska/Dutch Harbor in the eastern Aleutian Islands. Hypocenters of the earthquakes generally ranged between 0 and 8 km depth. The events had magnitudes of 0-1.5, so they were too small to be felt by humans. The earthquakes were not thought to be immediate precursors to eruptive activity because similar fluctuations in seismic activity have been observed at a number of Aleutian volcanoes and were not followed by eruptions. The level of concern color code remained at Green.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of a) U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (Email: tlmurry@usgs.gov, URL: http://www.avo.alaska.edu/), 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 ice-covered, 1800-m-high Makushin volcano on northern Unalaska Island west of the town of Dutch Harbor is capped by a 2.5-km-wide caldera. The broad, domical structure of Makushin contrasts with the steep-sided profiles of most other Aleutian stratovolcanoes. Much of the volcano was formed during the Pleistocene, but the caldera (which formed about 8000 years ago), Sugarloaf cone on the ENE flank, and a cluster of about a dozen explosion pits and cinder cones at Point Kadin on the WNW flank, are of Holocene age. A broad band of NE-SW-trending satellitic vents cuts across the volcano. The composite Pakushin cone, with multiple summit craters, lies 8 km to the SW of Makushin. Frequent explosive eruptions have occurred during the past 4000 years, sometimes accompanied by pyroclastic flows and surges. Geothermal areas are found in the summit caldera of Makushin and on the SE and eastern flanks of the volcano. They represent the largest and most investigated high-temperature geothermal resources in Alaska. Small-to-moderate explosive eruptions have been recorded at Makushin since 1786.

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1995 Jan 30 1995 Jan 30 Confirmed 1 Historical Observations
1993 Aug 1994 Jan 19 (?) Confirmed 1 Historical Observations
1987 Mar 2 1987 Mar 2 Confirmed 1 Historical Observations
[ 1986 Apr 28 ] [ Unknown ] Discredited    
1980 May 1 ± 75 days Unknown Confirmed 1 Historical Observations SE side of summit
[ 1952 ] [ Unknown ] Uncertain    
1951 Dec 20 Unknown Confirmed 1 Historical Observations
1938 Oct Unknown Confirmed 2 Historical Observations
1926 Dec 30 Unknown Confirmed 2 Historical Observations
[ 1912 ] [ Unknown ] Uncertain    
1907 Unknown Confirmed   Historical Observations
1883 Unknown Confirmed 2 Historical Observations
[ 1867 ] [ Unknown ] Uncertain    
1865 Unknown Confirmed   Historical Observations
[ 1844 ± 1 years ] [ Unknown ] Uncertain    
[ 1827 ] [ 1838 ] Uncertain 2  
1826 Jun Unknown Confirmed 3 Historical Observations
[ 1818 ] [ Unknown ] Uncertain    
1802 Unknown Confirmed 3 Historical Observations
[ 1792 Feb 14 ] [ Unknown ] Uncertain    
[ 1790 Jun 7 ] [ Unknown ] Uncertain    
1768 1769 Confirmed 3 Historical Observations
1150 ± 500 years Unknown Confirmed   Tephrochronology
0550 BCE ± 900 years Unknown Confirmed   Tephrochronology
1750 BCE (?) Unknown Confirmed   Radiocarbon (uncorrected)
3650 BCE ± 1850 years Unknown Confirmed 4 Tephrochronology
6100 BCE ± 50 years Unknown Confirmed 5 Radiocarbon (uncorrected)
6650 BCE ± 200 years Unknown Confirmed   Radiocarbon (uncorrected)

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.



Synonyms
Aigagin | Ajagin | Wesselow | Makouchine | Ognedieshutshai Gora | Ayagsh | Ajagisch


Cones
Feature Name Feature Type Elevation Latitude Longitude
Pakushin Cone 1050 m 53° 49' 42" N 166° 58' 43" W
Point Kadin Vent 53° 55' 0" N 167° 3' 0" W
Sugarloaf Cone 580 m 53° 55' 0" N 166° 48' 0" W


Thermal
Feature Name Feature Type Elevation Latitude Longitude
Lower Glacier Valley Thermal 53° 49' 4" N 166° 54' 26" W
Makushin Valley Thermal 53° 53' 27" N 166° 50' 9" W
Unnamed Thermal 53° 53' 15" N 166° 55' 0" W
Upper Glacier Valley Thermal 53° 50' 48" N 166° 53' 0" W
Makushin volcano is a large, ice-covered volcano on northern Unalaska Island. This March 2, 1987, view from the NE shows a small steam column originating from a vent at the left side of the broad summit and drifting about 3 km to the WNW. A 2-km-wide summit caldera helps give the volcano a broad, dome-like structure that contrasts with the steep-sided profiles of most other Aleutian stratovolcanoes. Minor explosive eruptions have occurred during historical time.

Photo by Harold Wilson (Peninsula Airways), 1987 (courtesy of John Reeder, Alaska Div. Geology Geophysical Surveys).
An aerial view of the summit area of Makushin Volcano, a 2036-m-high stratocone in the northern part of Unalaska Island in the eastern Aleutians, shows steam rising from a crater (left center). The broad summit of Makushin is truncated by a 2.5-km-wide caldera of Holocene age and contains an active cinder cone that has produced minor explosive eruptions in historical time.

Photo by Chris Nye, 1982 (Alaska Division of Geological & Geophysical Surveys).
The Point Kadin vents low on the NW flank of Makushin volcano are a dozen or so explosion pits and small cinder cones. They were erupted along a WNW-trending fracture zone that extends to the coast.

Photo by Chris Nye, 1994 (Alaska Division of Geological & Geophysical Surveys, Alaska Volcano Observatory).

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.

Beget J E, Nye C J, Bean K W, 2000. Preliminary volcano-hazard assessment for Makushin volcano, Alaska. Alaska Div Geol Geophys Surv, Rpt Invest, 2000-4: 1-22.

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

Drewes H, Fraser G D, Snyder G L, Barnett H F, 1961. Geology of Unalaska Island and adjacent insular shelf, Aleutian Islands, Alaska. U S Geol Surv Bull, 1028-S: 583-676.

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.

Myers J D, 1994. The Geology, Geochemistry and Petrology of the recent Magmatic Phase of the Central and Western Aleutian Arc. Unpublished manuscript, unpaginated.

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.

Volcano Types

Stratovolcano
Caldera
Pyroclastic cone(s)

Tectonic Setting

Subduction zone
Intermediate crust (15-25 km)

Rock Types

Major
Andesite / Basaltic Andesite
Basalt / Picro-Basalt
Trachyandesite / Basaltic trachy-andesite
Dacite
Minor
Trachyte / Trachyandesite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
0
0
3,437
3,850

Affiliated Databases

Large Eruptions of Makushin 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.