A Dynamic Process Model of Palsa Genesis and Development based on Geomorphologic Investigations at the Boundary Ridge Palsa Bog

• Main Authors: Near Schefferville Quebec, David Alan Carlson, O David, Alan Carlson
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2005
• Subjects: Ice; palsa; palsas; permafrost
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.130.2009; http://digital.library.mcgill.ca/ethesis /theses/20-david_alan_carlson.pdf

This original research of seasonal thermodynamic and dynamic geomorphologic processes at the Boundary Ridge palsa bog near Schefferville, Quebec reports characteristic differences in heat flow (Q,), and resulting permafrost mass aggradation/degradation behavior, between a mature-phase palsa (Palsa A) and young-phase palsa (Palsa B). Quantitative analysis of September 1976-August 1977 thermal data indicates how changing palsa material characteristics and bog thermodynamics affect palsa geomorphology. Q, patterns for Palsa A show greater amplitude, and shorter active-layer heat loss duration, at its center than along its periphery. Basal active-layer ice aggradation was more evident in Palsa A than Palsa B. Although Palsa A experienced lesser Q, amplitudes than Palsa B, increased Q,, phase lag resulted in more heat loss and productive ice growth at depth. Palsas A and B experienced permafrost-zone isothermal conditions just below 0°C for seven to eight months of the year, interrupted only by the winter