Late Quaternary Climate Change Across Northern Alaska: A Comparison of Lake-Level and Pollen Variations

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Abstract ATM-9500906 Finney, Bruce University of Alaska Title: Late Quaternary Climate Change Across Northern Alaska: A Comparison of Lake-Level and Pollen Variations This research project will address paleoclimatic questions and hypotheses for northern Alaska during the late-Quaternary (21,000 yr BP to present) using lake-level records as proxies for effective moisture. Results of climate model simulations and conceptual paleoclimate scenarios provide hypotheses to be tested against the geologic record. Other questions are derived from regional changes in the paleovegetational record that require climatic explanations. Specific paleoclimatic questions are: 1) was there an east-west gradient in effective moisture across northern Alaska during the late glacial as well as the Holocene, 2) when did the major increase in effective moisture related to late-glacial circulation changes occur, 3) was precipitation either enhanced or reduced during the period 11,000-6000 (calibrated) yr BP, when temperatures were probably warmer that present, and 4) are there other rapid, regional effective moisture changes in the record? The major contributions of this research will be 1) empirical data on regional paleohydrology, and 2) an assessment of changes in vegetation and other factors of the terrestrial system (e.g., eolian processes and watershed geochemistry) in the light of the paleohydrologic and other paleoclimatic data.