Variability of Lake Ice Growth and Quality in the Schefferville Region, Central Labrador—Ungava

Abstract

Abstract An examination of rates of ice growth, actual ice thickness and the quality of the lake ice profile on Knob Lake, central Labrador—Ungava, showed that all these factors were extremely variable. Three sites were established on Knob Lake from 1957 to 1961, and a similar sequence of sites was established on a neighbouring lake, Maryjo Lake, from 1959 to 1961. Significant variations occurred within a single lake body from site to site, though it was noted that certain patterns of ice growth and quality did occur throughout most years and could be directly related to patterns of snow accumulation on the lake. Variations from lake to lake were found to be least at the centre lake sites, probably because snow cover was always least at these sites and would not affect heat loss so greatly as at the marginal sites. It is suggested that the majority of empirical formulae proposed for lake ice growth are unrealistic for short-term forecasting of ice thickness and growth, and even long-term forecasting, using accumulated degree-days of frost, only gives average values. The only answer is repeated samplings on any lake, until such time that sufficient data are gathered for a full statistical approach based on probability analysis.