FREEZE-THAW FREQUENCIES AND MECHANICAL WEATHERING IN CANADA*

• Main Author: J. Keith Fraserf
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Arctic; Canada; Riven; Subarctic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.579.1476; http://pubs.aina.ucalgary.ca/arctic/arctic12-1-40.pdf

T HE repeated freezing and thawing of water in rock crevices and soil material is recognized as an important factor in mechanical weather-ing. The comparative importance of the process in northern and southern Canada has been examined in this preliminary study, which is not concerned with weathering under alpine conditions, and only indirectly with the role of freezing and thawing in the creation of patterned ground. Mechanical weathering is defined as the disintegration of rock in place, as opposed to chemical decomposition or to erosion, which requires a transporting agent. The freeze-thaw frequency at a particular station is the annual number of times the recorded temperature falls below the point of effective freeze following a period when the temperature was at or above the point of effective thaw. Scattered through the descriptive literature pertaining to arctic and subarctic regions are references (Tarr 1897, Eakin 1916, Jenness 1952, Bird 1955) to the widespread occurrence of frost-riven rock materials. rock deserts (felsenmeere), talus concentrations and comminuted erratics. This