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TitleSensitivity of the Laurentian Great Lakes to climate change, progress using an early Holocene example
AuthorLewis, C F M; Croley, T E, II; King, J W; Blasco, S M; McAndrews, J H; McCarthy, F M G
SourceInternational Association for Great Lakes Research - book of abstracts; 2007 p. 111
Alt SeriesEarth Sciences Sector, Contribution Series 20070116
Meeting50th Great Lakes Conference, International Association for Great Lakes Research; University Park, PA; US; May 28 - June 1, 2007
AreaCanada; United States of America
Subjectsenvironmental geology; hydrogeology; Nature and Environment; climate effects; climatic fluctuations; climate; hydrologic budget; hydrologic environment; hydrologic properties; water levels; limnology; climate change
ProgramEnhancing resilience in a changing climate
AbstractGeologic evidence has recently shown that Huron-Michigan water levels fell below their overflow outlet about 7900 14C years ago. This lowstand episode was probably caused by excess evaporation in a dry climate when flow from upstream glacial sources bypassed the Great Lakes basins. As some projections of future climate suggest lake levels may change beyond the range of instrumentally-observed variation, climatic-hydrologic sensitivity in models of future scenarios can only be extrapolated from present hydrology and past high-amplitude climatic-hydrologic change events. Current progress towards the goal of assessing the above event consists of 1) modeling to assess temperature and precipitation excursions that would drive the present lakes into hydrological closure, 2) application of climate transfer function analysis to derive proxy temperature and precipitation information from vegetation pollen records, 3) recovery of small headwater lake sediments for new proxy climate records in watersheds around the Great Lakes, and 4) validation of the Great Lakes lowstand. Future studies and modeling will consider the additional climatic-hydrologic effects of early Holocene insolation, wind-fields, and paleogeography.