CGRG Bibliography of Canadian Geomorphology
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Author : Begin, Y.
Date : 2000.
Title : Tree-ring dating of intraseasonal lake level fluctuations at the subarctic-boreal interface.
Publication : International Conference on Dendrochronology for the Third Millennium, 2-7 April, 2000 Mendoza, Argentina.
Issue : Abstract
Page(s) :
Abstract
Extreme water levels of two large lakes in northern Québec were dated over the past century by 1) ice scars on shoreline tree, 2) sequences of reaction wood in shore trees tilted by wave erosion, and 3) narrow rings in riparian trees protected against shore erosion, but submitted to rises in the water table controlled by lake levels. A major change in both the amplitude and frequency of the ice-flood regime occurred in the 1930s as the result of increased snowfall. A rise in amplitude of summer lake levels was indicated by the position and number of trees tilted by waves. The frequency of summer floods coinciding with earlier spring floods has increased since the 1930s, suggesting a high frequency of years with snowy winters immediately followed by rainy summers. Intercalary years are characterized by the absence of erosion markers, suggesting that low water levels resulted from dry conditions. The amplitude of the ice-flood is postulated to be related to the late freeze-up of Hudson Bay that provides moisture during atmospheric lows, resulting in abundant snowfalls in early winter. Contrasted year-to-year summer lake levels seem to be the expression of variation in summer rainfall.
Bibliography of Canadian Geomorphology