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  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 56.88°N
  • 158.17°W

  • 1341 m
    4398 ft

  • 312090
  • Latitude
  • Longitude

  • Summit

  • Volcano

There are no activity reports for Aniakchak.

 Available Weekly Reports

There are no Weekly Reports available for Aniakchak.

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
[ 1951 Jun 25 ] [ 1951 Jun 25 ] Discredited    
[ 1942 ] [ Unknown ] Uncertain    
1931 May 1 1931 Jun 13 (in or after) Confirmed 4 Historical Observations West and SW caldera floor
1560 ± 50 years Unknown Confirmed 4 Radiocarbon (uncorrected) NW & S caldera floor (Half Cone, Vent Mtn)
1550 (?) Unknown Confirmed   Radiocarbon (uncorrected) SE caldera floor (New Cone)
1390 (?) Unknown Confirmed   Radiocarbon (uncorrected) NW caldera floor (Half Cone?)
1220 ± 150 years Unknown Confirmed   Tephrochronology NW caldera floor (Half Cone)
1050 (?) Unknown Confirmed   Tephrochronology Vent Mtn and other vents?
0700 ± 300 years Unknown Confirmed 0 Tephrochronology S & NW caldera floor (Vent Mtn & Half Cone)
0460 (?) Unknown Confirmed   Radiocarbon (uncorrected)
0200 Unknown Confirmed   Tephrochronology Northern & western caldera floor
0350 BCE (?) Unknown Confirmed   Radiocarbon (uncorrected)
1645 BCE ± 10 years Unknown Confirmed 6 Ice Core
2550 BCE ± 500 years Unknown Confirmed   Tephrochronology
5250 BCE ± 2700 years Unknown Confirmed 6 Tephrochronology

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. 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. Additional discussion of data sources can be found under Volcano Data Criteria.

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

Dreher S T, Eichelberger J C, Larsen J F, 2005. The petrology and geochemistry of the Aniakchak caldera-forming ignmbrite, Aleutian Arc, Alaska. J Petr, 46: 1747-1763.

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..

McGimsey R G, Waythomas C F, Neal C A, 1994. High strand and catastrophic draining of intracaldera Surprise Lake, Aniakchak volcano, Alaska. In: Till A B, Moore T E (eds) {Geologic Studies in Alaska by the U. S. Geological Survey in 1993}, U S Geol Surv Bull 2017: 59-71.

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.

Neal C A, McGimsey R G, Miller T P, Riehle J R, Waythomas C F, 2001. Preliminary volcano-hazard assessment for Aniakchak volcano, Alaska. U S Geol Surv Open-File Rpt, 00-519: 1-35.

Newhall C G, Dzurisin D, 1988. Historical unrest at large calderas of the world. U S Geol Surv Bull, 1855: 1108 p, 2 vol.

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.

Smith W R, 1925. Aniakchak Crater, Alaska Peninsula.. U S Geol Surv Prof Pap, 132-J: 139-149.

One of the most dramatic calderas of the Aleutian arc, the 10-km-wide Aniakchak caldera was formed around 3400 years ago during a voluminous eruption in which pyroclastic flows traveled more than 50 km north to the Bering Sea and also reached the Pacific Ocean to the south. At least 40 explosive eruptions have been documented from Aniakchak during the past 10,000 years, making it the most active volcano of the eastern Aleutian arc. A dominantly andesitic pre-caldera volcano was constructed above basement Mesozoic and Tertiary sedimentary rocks that are exposed in the caldera walls to elevations of about 610 m. The ice-free caldera floor contains many pyroclastic cones, tuff cones, maars, and lava domes. Surprise Lake on the NE side drains through The Gates, a steep-walled breach on the east side of the 1-km-high caldera rim. Vent Mountain and Half Cone are two long-lived vents on the south-central and NW caldera floor, respectively. The first and only confirmed historical eruption took place in 1931 from vents on the west and SW caldera floor.