pipkrake (needle ice) Columnar ice found beneath individual stones or patches of earth in the periglacial environment. It is a result of the relatively high thermal conductivity of such materials, leading to freezing under them when the temperature falls. Heaving of less than 0.1 m may occur by this process.

pipkrake(needle ice) Columnar ice found beneath individual stones or patches of earth in a periglacial environment. It is a result of the relatively high thermal conductivity of such materials, leading to freezing under them when the temperature falls. Heaving of less than 0.1 m may occur by this process.