No latest activity reported for Ugashik-Peulik.

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

Detterman R L, Wilson F H, Yount M E, Miller T P, 1987. Quaternary geologic map of the Ugashik, Bristol Bay, and western part of Karluk quadrangles, Alaska. {U S Geol Surv Map}, I-1801

Fierstein J, 2007. Explosive eruptive record in the Katmai region, Alaska Peninsula: an overview. {Bull Volc}, 69: 469-509

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

Kienle J, Swanson S E, 1983. Volcanism in the eastern Aleutian Arc: late Quaternary and Holocene centers, tectonic setting and petrology. {J Volc Geotherm Res}, 17: 393-432

Miller T P, 1984. Two-stage volcanism at the Ugashik-Peulik volcanic center, Alaska Peninsula. {Geol Soc Amer Abs Prog}, 16: 322

Miller T P, 2004. Geology of the Ugashik-Mount Peulik volcanic center, Alaska. {U S Geol Surve Open-File Rpt}, 2004-1009: 1-19

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

Smith W R, Baker A A, 1922. The Cold Bay-Chignik district, Alaska. {U S Geol Surv Bull}, 755-D: 156-157 & 191-192

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

The Ugashik-Peulik volcanic complex lies south of Becharof Lake and east of Upper Ugashik Lake. Late-Pleistocene caldera formation at Ugashik volcano was followed by the emplacement of at least 5 Holocene lava domes within the 4.5-km-wide caldera. Most of the caldera walls consist of basement sandstones of Jurassic age. Following caldera formation the small, 3 cu km Peulik stratovolcano grew 2.5 km to the north to a height of 1474 m, more than 500 m above that of Ugashik. Lava flows from Peulik cover the caldera rim to the south and extend to Becharof Lake, 6 km to the north. A small lava dome at 1200 m elevation on the east flank of Peulik was the source of a small block-and-ash flow. The summit of Peulik volcano contains a 1.5-km-wide crater breached to the west that is partially filled by a lava dome. Debris-avalanche deposits cover a 75 sq km area to the NW. A single documented historical eruption took place from Peulik volcano in 1814.