HR: 1400h
AN: V23A-13    [Abstracts]
TI: Comparison of Eruption Effects on Humans at Four North American Cinder Cones
AU: * Ort, M H
EM: michael.ort@nau.edu
AF: Environmental Sciences/Geology, Northern Arizona University, Flagstaff, AZ 86011, United States
AU: Elson, M D
EM: melson@desert.com
AF: Desert Archaeology, Inc., 3975 N. Tucson Blvd., Tucson, AZ 85716, United States
AU: Anderson, K C
EM: kirk.anderson@nau.edu
AF: Navajo Nation Archaeology, Northern Arizona University, Flagstaff, AZ 86011, United States
AB: Cinder-cone eruptions are typically low in volume and explosivity, but they can affect local populations profoundly. Comparisons of three prehistoric eruptions (Xitle, Sunset Crater, and Little Springs Volcano) and one historic eruption (Parícutin) in southwestern North America show that eruption effects vary dramatically due to eruption style, tephra blanket extent, climate, types of land use, the culture and complexity of the affected group, and resulting governmental action. Lava flows have long-term effects that extend little beyond the flow edges. These flows, however, are used for defensive purposes, providing refuges from invasion for those who know them well. In arid lands, tephra blankets serve as mulches, decreasing runoff and evaporation, increasing infiltration, and regulating soil temperature. Management and retention of these cinder mulches, which can open new areas for agriculture, becomes a priority for farming communities. In humid areas, though, the tephra blanket impedes plant growth and increases erosion. Cultural responses to eruptions vary, from collapse of an already declining culture at Xitle, fragmentation of society at Parícutin, dramatic changes and development of new technologies at Sunset Crater, to little apparent change at Little Springs volcano. Eruptions may be viewed as retribution for poor behavior and attempts are made to mollify angry gods. At Sunset Crater and Little Springs volcano, offerings (corn and pot sherds, respectively) were made at hornitos, rootless vents on the lava flows. Spatter containing the corn impressions and sherds was then carried away and incorporated into the walls of structures. This indicates ritual significance to the offerings.
DE: 8428 Explosive volcanism
DE: 8488 Volcanic hazards and risks
SC: Volcanology, Geochemistry, and Petrology [V]
MN: 2007 Joint Assembly