Expanding the scope of the term "periglacial"

Abstract

The traditional etymological definition of the periglacial zone, which relates it to areas located around glaciers, turns out to be insufficient. In many such regions, such as on the Canadian Shield, in the Appalachians, in Scandinavia or in Antarctica, periglacial processes are very weak or absent even though thermal conditions favour frequent temperature fluctuations. This is due, among other factors, to dense vegetation, thick soil cover and the lack of cyclic temperature changes around 0 °C.

At the same time, intensive periglacial processes occur in many areas not previously considered periglacial, such as intertropical deserts or numerous high-mountain regions, where temperature fluctuations around freezing are frequent.

For this reason, a broader understanding of the term “periglacial” is proposed, based on the actual occurrence of phenomena related to freeze–thaw cycles rather than solely on geographical location with respect to glaciers. The importance of three factors influencing the intensity of these processes is emphasised: moisture, vegetation cover, and the type and thickness of the soil. There is also a distinction between areas where periglacial processes may occur and those where they are truly active, which allows for a more complete presentation of their global distribution.