Taking the temperature of the Arctic past: Extracting temperature and precipitation information from bacterial lipids deposited in faunal remains from Cape Krusenstern, Alaska

Summary

Throughout his career, J. Louis Giddings explored the roles of climate on maritime and terrestrial resources and human ingenuity in adapting technologies and social strategies to exploit those resources under changing conditions. At Cape Krusenstern, Alaska, Giddings’ teams identified sequential occupations based on changing maritime adaptations but had no analytical tools for directly inferring key climatic parameters during periods of the Cape's occupation. Recently, our research group discovered that a widely used class of climate-sensitive bacterial lipid compounds—glycerol dialkyl glycerol tetraethers (GDGTs)—is well preserved in ancient bones. Research has demonstrated that these bacteria-derived GDGTs faithfully record mean annual air temperature (MAAT), soil pH, and, in relatively dry regions, precipitation. Direct reconstruction of climate conditions from archaeological materials, in this case non-human biological samples, with age control provided by archaeological contexts, has the potential to allow direct inference of key climatic and environmental parameters at the time individual sites were occupied, conditions to which those sites' occupants were adapting, and changes through time. This paper examines current research on bone-derived GDGTs using archived faunal collections from Giddings' excavations of Ipiutak through late prehistoric Inupiat settlements at Cape Krusenstern to reconstruct changing climate conditions at the time of those occupations.

This Resource is Part of the Following Collections

• Society for American Archaeology 81st Annual Meeting, Orlando, FL (2016)   •
• Envisioning and Re-envisioning Arctic Archaeology: The Enduring Legacies of J. Louis Giddings (1909-1964)

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