A Frost Tube for the Determination of Freezing in the Active Layer above Permafrost

• Published in: Canadian Geotechnical Journal
• Main Author: Mackay, J. Ross
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1973
• Subjects: Ice; permafrost
• Online Access: http://dx.doi.org/10.1139/t73-033; http://www.nrcresearchpress.com/doi/pdf/10.1139/t73-033

A frost tube which can be used in permafrost areas to determine both the downward and upward movements of the two freezing fronts in the active layer, during the fall freeze-back period, is described. The principle, which is based upon the differential vertical migration of fine and coarse particles resting upon an upward moving horizontal ice–water interface, is discussed. Attention is drawn to some of the ice characteristics of the active layer and top of the permafrost which result from upward freezing at the bottom of the active layer.