No latest activity reported for Aniakchak.

Below is a summary of eruption dates and Volcanic Explosivity Indices (VEI).

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.