Volcanism and the Aleutian Islands

Authors: Dixie West: Kansas University; Mitsuru Okuno: Fukuoka University; Kirsten Nicolaysen: Whitman College; Breanyn MacInnes: Central Washington University; Virginia Hatfield: Kansas University

Volcanoes created the Aleutian Islands, and volcanic eruptions periodically impacted humans inhabiting the archipelago. Sizable geological events potentially disrupted food sources by killing fish; clogging spawning streams; and smothering ground nesting bird colonies, shellfish beds and sea mammal rookeries (Black 1981; Workman 1979). Volcanism also must have produced a powerful psychological effect on prehistoric Unangax^ (Black 1981).


The August 2008 Kasatochi eruption in the central Aleutians is useful for understanding past geological impacts on humans and their natural world. The explosion covered the island with meters of ash, endangered USFWS biologists, killed thousands of chicks, and destroyed sea lion rookeries and the breeding grounds of over 100,000 ground nesting birds. Pyroclastic-flow deposits created a coastline approximately 400 m further into the sea, and initiated a small tsunami recorded by Atka, Adak and Amchitka tide gauges (USGS 2009)

Our research (e.g. Okuno et al. 2012; West et al. 2012) suggests that prehistoric peoples settled on north Adak Island nearly 7,000 years ago. Five major volcanic events are recorded on north Adak: the Main, Intermediate, Sandwich, YBO, and 40 Year ash occurrences (Black 1976). By dating plant materials charred by ash falls in prehistoric village sites and by comparing the relationship of these ashes with cultural layers, we can determine how human occupations were impacted by volcanic events. Site ADK-171, the earliest site on Adak, lies immediately above the Intermediate Ash that fell approximately 7200 years ago (Okuno et al. 2012). Cultural layers capping a poorly developed soil and Intermediate Ash indicate the volcanic explosion did not prevent humans from settling north Adak soon after the ash fell.


Recent North Pacific Rim research (e.g., Dumond 2011; Fitzhugh 2012) shows remarkable hunter-gatherer flexibility in the face of catastrophic geological events. Unangan resilience probably depended on multiple factors:

  • Intergenerational communication allowing all persons in any given group to recognize signs of an imminent disaster based on past experience of older individuals,
  • The capacity to pick up and move relatively quickly from impending danger,
  • An easily reproducible house architecture and technology if villages were destroyed and tools abandoned,
  • Possible communication with, and temporary aid from, Unangax^ living in nearby island groups, and
  • A remarkably consistent maritime ecosystem where adjacent islands possessed many, if not most, food resources and tool materials familiar to Unangan groups displaced by natural disasters.

The recently NSF funded research project “Collaborative Research: Geological Hazards, Climate Change, and Human/Ecosystems Resilience in the Islands of the Four Mountains” promises to add new information about the impacts of, and human reactions to, volcanic eruptions, tsunamis and other geological events in the eastern Aleutians. In 2014 Kirsten Nicolaysen, Breanyn MacInnes, Virginia Hatfield, and Dixie West will launch this three-year interdisciplinary research on Chuginadak and Carlisle Islands.

Black, Robert F. 1976.  Late Quaternary Glacial Events, Aleutian Islands, Alaska. In D. J. Easterbrook and V. Sibrava (eds.), Quaternary Glaciations in the Northern Hemisphere: IUGS-UNESCO International Geological Correlation Program, Project 73-1-24, 285-301. Bellingham, International Union of Quaternary Research.

Black, Lydia. 1981.Volcanism as a Factor in Human Ecology: The Aleutian Case. Ethnohistory 28(4), 313-333.

Dumond, Don. 2011. Archaeology on the Alaska Peninsula: The Northern Section. Fifty Years Onward. University of Oregon Anthropological Papers No. 78. Eugene.

Fitzhugh, Ben. 2012. Hazards, Impacts, and Resilience Among Hunter-Gatherers of the Kuril Islands, pp.19-42.  In J. Cooper and P. Sheets (eds.), Surviving Sudden Environmental Change: Answers from Archaeology. University Press of Colorado, Boulder.

Okuno, Mitsuru, Keiji Wada, Toshio Nakamura, Lyn Gualtieri, Brenn Sarata, Dixie West, and Masayuki Torii. 2012. Holocene Tephra Layers on the Northern Half of Adak Island in the West-Central Aleutian Islands, Alaska, pp. 59-74. In (D. West, V. Hafield, E. Wilmerding, C. Lefèvre, and L. Gualtieri, eds.), The People Before: the Geology, Paleoecology and Archaeology of Adak Island, Alaska. BAR International Series 2322, Oxford.

USGS. 2009. Small Volcano—Big Eruption  http://alaska.usgs.gov/science/kasatochi/2008_eruption.php

West, D., V. Hatfield, E. Wilmerding, C. Lefèvre, L. Gualtieri (eds.). 2012. The People Before: The Geology, Paleoecology and Archaeology of Adak Island, Alaska. British Archaeological Reports, 2322, Oxford.

Workman, William. 1979. The Significance of Volcanism in the Prehistory of Subarctic Northwest North America. In Volcanic Activity and Human Ecology. P. Sheets and D. Grayson, eds., pp. 339-371. Academic Press. New York.


One thought on “Volcanism and the Aleutian Islands

  1. Dear AIWG colleagues:
    The Islands of the Four Mountains research will have a very strong geological component. Archaeologists, biologists and geologists will work closely together to interpret the relationships among the physical, natural and prehistoric/historic cultural worlds in this island group.

    Islands of Four Mountains geologists include:
    Kirsten Nicolaysen, Whitman College, Washington;
    Mitsuru Okuno, Fukuoka University, Japan;
    Breanyn MacInnes, Central Washington, University;
    Christina Neal, Alaska Volcano Observatory;
    Pavel izbekov, University of Alaska, Fairbanks;
    John Lyons, Alaska Volcano Observatory;
    Francis Griswold, Central Washington University
    Max Kaufman, Alaska Volcano Observatory

    When the post for the AIWG website was written some months back, we had not yet determined who some of the geologists would be participating in the Four Mountains fieldwork.

    Here is a link to the Facebook page that the Four Mountains team will try to maintain as we conduct the research.I am not confident that we will be able to post information while in the field. I am leaving the Facebook and Twitter to my tech savvy colleagues (Virginia Hatfield, Kirsten Nicolaysen, and Breanyn MacInnes).


    Dixie West

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