Based on analysis of satellite imagery, pilot observations, KVERT reports, and information from AVO, the Anchorage VAAC reported that on 11 May strong winds in the Katmai area re-suspended loose ash deposited during the 1912 eruption. The Volcano Alert Level remained at Normal and the Aviation Color Code remained at Green.

11 May 2011            Back to Top

Based on analysis of satellite imagery, pilot observations, KVERT reports, and information from AVO, the Anchorage VAAC reported that on 11 May strong winds in the Katmai area re-suspended loose ash deposited during the 1912 eruption. The Volcano Alert Level remained at Normal and the Aviation Color Code remained at Green.

Sources: Anchorage Volcanic Ash Advisory Center (VAAC)

24 November 2010            Back to Top

Based on analysis of satellite imagery and information from AVO, the Anchorage VAAC reported that on 29 November strong winds in the Katmai area picked up loose ash deposited during the 1912 eruption and carried it SE over Kodiak Island. The Volcano Alert Level remained at Normal and the Aviation Color Code remained at Green.

Sources: Anchorage Volcanic Ash Advisory Center (VAAC)

2 November 2005            Back to Top

Strong winds in the Katmai area picked up loose ash deposited during the 1912 eruption and carried it E over Kodiak Island. AVO recorded a large area of resuspended ash on satellite imagery. The National Weather Service estimated that the top of the plume was at 1.5 km (5,000 ft) a.s.l. Katmai remained at Concern Color Code Green.

Sources: Alaska Volcano Observatory (AVO)

17 September 2003            Back to Top

According to the National Weather Service, strong winds on 21 September in the Katmai area picked up old, loose volcanic ash and carried it E over Kodiak Island. AVO received reports that some of this material fell in Kodiak. This was not the result of volcanic activity and no eruption occurred. Re-suspended volcanic ash should be considered as hazardous as primary volcanic ash, and a threat to aircraft. The volcanoes in the Katmai cluster remained at Concern Color Code Green.

Sources: Alaska Volcano Observatory (AVO)

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.

Curtis G H, 1968. The stratigraphy of the ejecta from the 1912 eruption of Mount Katmai and Novarupta, Alaska. {Geol Soc Amer Mem}, 116: 153-210

Fenner C N, 1930. Mount Katmai and Mount Mageik. {Zeit Vulk}, 13: 1-24

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

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

Hildreth W, 1983. The compositionally zoned eruption of 1912 in the Valley of Ten Thousand Smokes, Katmai National Park, Alaska. {J Volc Geotherm Res}, 18: 1-56

Hildreth W, 1987. New perspectives on the eruption of 1912 in the Valley of Ten Tousand Smokes, Katmai National Park, Alaska. {Bull Volc}, 49: 680-693

Hildreth W, Fierstein J, 2000. Katmai volcanic cluster and the great eruption of 1912. {Geol Soc Amer Bull}, 112: 1594-1620

Hildreth W, Lanphere M A, Fierstein J, 2003b. Geochronology and eruptive history of the Katmai volcanic cluster, Alaska Peninsula. {Earth Planet Sci Lett}, 214: 93-114

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

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

Prior to 1912, Mount Katmai was a compound stratovolcano with four NE-SW-trending summits, most of which were truncated by caldera collapse in that year. Two or more large explosive eruptions took place from Mount Katmai during the late Pleistocene. Most of the two overlapping pre-1912 Katmai volcanoes are Pleistocene in age, but Holocene lava flows from a flank vent descend the SE flank of the SW stratovolcano into the Katmai River canyon. Katmai was initially considered to be the source of the Valley of Ten Thousand Smokes ash flow in 1912. However, the 3 x 4 km wide caldera of 1912 is now known to have formed as a result of the voluminous eruption at nearby Novarupta volcano. The steep walled young caldera has a jagged rim that rises 500-1000 m above the caldera floor and contains a 250-m-deep, still-rising lake. Lake waters have covered a small post-collapse lava dome (Horseshoe Island) that was seen on the caldera floor at the time of the initial ascent to the caldera rim in 1916. Post-1912 glaciers have formed on a bench within Katmai caldera.