Last modified: 2011-12-17
Abstract
In high altitude and high latitude regions of North America, researchers have documented ancient organic cultural remains emerging from patches of permanent ice and snow known as ice patches (Dixon, et al. 2005; Hare, et al. 2004; Lee, et al. 2006; Vanderhoek, et al. 2007). Collections of rare and well-preserved organic artifacts from these vanishing archaeological contexts provide new insights about the interactions between hunter-gatherers and mountainous environments. Ongoing ice patch research in central Alaska and the Canadian Yukon has demonstrated that ice patches tend to be located on north-facing slopes and high elevation flats above such slopes. In Alaska, ice patches occur at different elevations in different parts of the state, and many exhibit dramatic ablation in response to climate change. Their formation and survival is dependent on a number of interactive variables including precipitation, slope, aspect, elevation, albedo, basal topographic characteristics, prevailing winter wind direction, and snow catchment area .
Methods for ice patch discovery include fixed wing aerial survey, analysis of satellite imagery and other remote sensing data, and helicopter-supported pedestrian survey of potential ice patches. Although aerial survey and remote sensing analyses can reduce the potential survey universe, it is necessary to conduct pedestrian survey in order to determine whether culturally modified objects are exposed at the surface of an ice patch. Because helicopter time is extremely expensive and survey areas may encompass hundreds of square miles of mountainous terrain, it is imperative to accurately select areas with the highest potential for ice patch preservation. This research develops a predictive model for ice patch location using slope, aspect, elevation, and solar radiation values derived from a 23m ASTER digital elevation model (DEM).
Topographic parameters for five Alaskan ice patches were used to create bounding values for environmental contexts that can support permanent ice. The model was applied to unsurveyed areas of Katmai National Park and focused the survey area on 1,083 km2, or 6.5% of the Park’s 16,563 km2 area. Ground-truthing in 2011 (a low-melt summer) confirmed the presence of permanent ice in these areas, but failed to locate ancient cultural remains.
Dixon, E. J., W. F. Manley and C. M. Lee
2005 The emerging archaeology of glaciers and ice patches: Examples from Alaska's Wrangell-St. Elias National Park and preserve. American Antiquity 70(1):129-143.
Hare, P. G., S. Greer, R. Gotthardt, R. Farnell, V. Bowyer, C. Schweger and D. Strand
2004 Ethnographic and archaeological investigations of alpine ice patches in southwest Yukon, Canada. Arctic 57(3):260-272.
Lee, C. M., J. B. Benedict and J. B. Lee
2006 Ice Patches and Remnant Glaciers: Paleontological Discoveries and Archaeological Possibilities in the Colorado High Country. Southwestern Lore 72(1):26-43.
Vanderhoek, R., R. M. Tedor and C. E. Holmes
2007 Cultural Materials Recovered From Ice Patches In The Denali Highway Region, Central Alaska, 2003-2005. Alaska Journal of Anthropology 5(2):185 - 200.