Cyclic Development and Thermokarstic Degradation of Palsas in the Mid‐Alpine Zone at Leirpullan, Dovrefjell, Southern Norway

Subarctic Thermokarst Ponds: Investigating Recent Landscape Evolution and Sediment Dynamics in Thawed Permafrost of Northern Québec (Canada)

“…The studied thermokarst landscape is similar to many others formed during the Holocene along the eastern coast of Hudson Bay (Payette et al, 2004;Vallée and Payette, 2007;Calmels et al, 2008a), and also elsewhere in subarctic regions where permafrost is rapidly degrading since the early 20th century (e.g., Zuidhoff and Kolstrup, 2000;Sannel and Kuhry, 2011). However, most studies in these regions (including northeastern Canada) have considered thermokarst ponds as the final or transitional stage in the degradation sequence of permafrost mounds, or as an indicator of ancient periglacial forms (e.g., Allard et al, 1996;Matthews et al, 1997;Luoto and Seppälä, 2003;Payette et al, 2004;Calmels et al, 2008a). With the exception of recent work done in a subarctic palsa peatland of western Siberia (Shirokova et al, 2009;Audry et al, 2011;Pokrovsky et al, 2011), few studies have investigated the links between external (landscape) and internal (sedimentology, biogeochemistry) processes controlling thermokarst pond evolution.…”

The remnants of Younger Dryas lithalsas on the Hautes Fagnes Plateau in Belgium and elsewhere in the world

“…At last, a group of similar cryogenic mounds has been described by Matthews et al (1997) in southern Norway, at a latitude of 62°21′N and a longitude of 9°18′E. The features seem to have appeared under a thin peat layer (less than 20 cm thick), which was later eroded, and to have evolved as mineral mounds, looking like lithalsas.…”

Palsa Development and Associated Vegetation in Northern Sweden

“…In the present study it was found that the bog vegetation is not homogenous, neither in composition nor in height, and it is possible that local differences in vegetation might influence snow distribution and thus contribute to the location of future palsas. Alternatively, palsa formation might start in summer by local preservation of frozen ground under more insulating vegetation (Matthews et al, 1997). This possibility appears to be supported by a study by Kuhry (1998) who found that development of dry peat surfaces with Sphagnum fuscum was a trigger for palsa formation.…”