CGRG Bibliography of Canadian Geomorphology
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Author : Griffiths, K.; Selbie, D.T.; Chen, G.; Sweetman, J.N.; Michelutti, N.; Gregory-Eaves, I.; and Smol, J.P.
Date : 2011.
Title : The influence of terrestrial ice fields on Holocene climate: a paleolimnological assessment of three lakes from the Southwest Yukon.
Publication : Geohydro 2011. Joint Meeting of the Canadian Quaternary Association and the Canadian Chapter of the International Association of Hydrogeologists. August 28-31, 2011. Quebec City, Quebec.
Issue :
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Abstract
Anthropogenic climate warming has been most pronounced at high latitudes, resulting in major changes in northern terrestrial and aquatic ecosystems. However, there exists considerable heterogeneity in the rate and nature of climate change not accounted for by current climate models. Paleoclimatic reconstructions from some lakes in the Southwest Yukon revealed relatively complacent climate trends as compared to other high-latitude/high altitude sites. We hypothesize that the Wrangell - St. Elias ice fields, which lie along the Southwest Margin of the Yukon, are moderating climate at a regional scale and dampening the effects of recent climate warming. Our conceptual model is that lakes closest to the ice fields would have a muted response to climatic change, so long as the ice fields are of sufficient size to buffer air temperatures. However, if cryospheric features are moderating regional temperatures, the complete ablation of ice may result in rapid warming and possibly the crossing of ecological thresholds. To investigate the response of lakes in the Southwest Yukon to Holocene climate fluctuations, we are reconstructing Holocene climate using larval chironomid remains (non-biting midges) preserved in sediments from three lakes with varying proximity to the ice field. By comparing the long cores to regional and global periods of glacial advance/retreat, we hope to place the current trends into a longer temporal context and model the changing influence of the Wrangell-St Elias ice fields. Additionally, we will be focusing on periods of past global warmth (e.g. the Holocene Thermal Maximum) which may be of similar magnitude to those projected under future warming to identify possible rapid warming events or threshold ecosystem responses. Our investigation into this potential climate mechanism may provide additional insights to the heterogeneity of climate change in the Arctic and lead to the development of more comprehensive management strategies in the SW Yukon.
Bibliography of Canadian Geomorphology