CGRG Bibliography of Canadian Geomorphology
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Author : Beierle, B.D.
Date : 1998
Title : Climate change at the Pleistocene-Holocene boundary: equilibrium line altitude changes in the southern Canadian Rocky Mountains
Publication : 1998 Annual Meeting, Geological Society of America, Toronto, October 26-29. Abstracts with Program.
Issue :
Page(s) :
Abstract
The extent to which glaciers occupied alpine areas in the southern Canadian Rocky Mountains following the abrupt termination of the Younger Dryas advance is critical for assessing the relative change in climate at the end of the Pleistocene. Sediment cores from lakes in the southern Canadian Rocky Mountains suggest that with the termination of the Younger Dryas, climate abruptly warmed, resulting in the rapid deglaciation of alpine areas. On the basis of sedimentological, isotopic and aquatic macrofossil changes, it is hypothesized that Equilibrium Line Altitudes (ELAs) in these areas increased from modern levels of 23-2800 m to at least 3000 m, and possibly higher, resulting in the complete ablation of most alpine glacial ice in the southern Canadian Rocky Mountains. Calculations of climatic changes required to elevate ELAs to this extent suggest that temperatures may have increased by as much as 4.5° C at ca. 10 000 BP, with ice free conditions persisting until after the 6800 BP Mazama tephra. The abrupt changes noted in the sedimentology of these lakes, and the paleotemperature increase inferred from those changes correlates both in terms of magnitude and apparent rate of change with records from the North Atlantic ocean cores and the Greenland ice cores, suggesting that abrupt climatic change at the end of the Pleistocene may have had equal effects outside of circum-North Atlantic areas as in those within.
Bibliography of Canadian Geomorphology