Great Sitkin Forty Year Ash
Start: 1750 [1]
Event Type: Explosive
Description: From Kiriyanov and Miller (1997): "AD-1 has a thickness of 6-10 cm and consists of a pinkish-gray clay- or silt-size material containing lenses of fine-grained volcanic sand. The main components are volcanic glass (69%) and plagioclase (21%). The characteristic features are a significant amount of pyroxenes (6%) and absence of green or brown hornblend (Fig. 5 [in original text]). More than 50 wt. % of the sample are particles smaller than 0.071 mm in size. The glass is colorless, juvenile, and contains microlites of plagioclase. The approximate carbon-14 age of the ash is less than 200 years (P. Black determined its carbon-14 age of 40 years, Table 1 [in original text])."
References Cited
[1] Volcanic ashes of Adak Island, Aleutian Islands, Alaska [Vulkanicheskiye peply na o-ve Adak (Aleutskiye o-va, SShA)], 1997
Kiriyanov, V. Y., and Miller, T. P., 1997, Volcanic ashes of Adak Island, Aleutian Islands, Alaska [Vulkanicheskiye peply na o-ve Adak (Aleutskiye o-va, SShA)]: Volcanology and Seismology [Vulkanologiya I Seysmologiya], v. 19, n. 1, p. 52-77.[2] Holocene Tephra Layers on the Northern Half of Adak Island in the West-Central Aleutian Islands, Alaska, 2012
Okuno, M., Wada, K., Nakamura, T., Gualtieri, L., Sarata, B., West, D., and Torii, M., 2012, Holocene Tephra Layers on the Northern Half of Adak Island in the West-Central Aleutian Islands, Alaska, in West, D., Hatfield, V., Wilmerding, E., Lefevre, C. and Gualtieri, L. (eds.): The People Before: The Geology, Paleoecology and Archaeology of Adak Island, Alaska, Oxford, UK, p. 61-75.[3] Preliminary volcano-hazard assessment for Kanaga Volcano, Alaska, 2002
Waythomas, C. F., Miller, T. P., and Nye, C. J., 2002, Preliminary volcano-hazard assessment for Kanaga Volcano, Alaska: U.S. Geological Survey Open-File Report 02-0397, 27 p., 1 sheet.
full-text PDF 38.5 MB
map sheet plate (PDF) 17.5 MB Complete Eruption References
Volcanic ashes of Adak Island, Aleutian Islands, Alaska [Vulkanicheskiye peply na o-ve Adak (Aleutskiye o-va, SShA)], 1997
Kiriyanov, V. Y., and Miller, T. P., 1997, Volcanic ashes of Adak Island, Aleutian Islands, Alaska [Vulkanicheskiye peply na o-ve Adak (Aleutskiye o-va, SShA)]: Volcanology and Seismology [Vulkanologiya I Seysmologiya], v. 19, n. 1, p. 52-77.
Holocene Tephra Layers on the Northern Half of Adak Island in the West-Central Aleutian Islands, Alaska, 2012
Okuno, M., Wada, K., Nakamura, T., Gualtieri, L., Sarata, B., West, D., and Torii, M., 2012, Holocene Tephra Layers on the Northern Half of Adak Island in the West-Central Aleutian Islands, Alaska, in West, D., Hatfield, V., Wilmerding, E., Lefevre, C. and Gualtieri, L. (eds.): The People Before: The Geology, Paleoecology and Archaeology of Adak Island, Alaska, Oxford, UK, p. 61-75.
Preliminary volcano-hazard assessment for Kanaga Volcano, Alaska, 2002
Waythomas, C. F., Miller, T. P., and Nye, C. J., 2002, Preliminary volcano-hazard assessment for Kanaga Volcano, Alaska: U.S. Geological Survey Open-File Report 02-0397, 27 p., 1 sheet.
full-text PDF 38.5 MB
map sheet plate (PDF) 17.5 MB 