The mechanism of repeated-segregation for the formation of thick layered ground ice

In this article, a mechanism of repeated-segregation for the formation of thick layered ground ice has been suggested. The mechanism consists of the following processes: (1) Moisture migration to the freezing front and ice lensing there as a result of upward freezing from permafrost. (2) Unequal law of migration of unfrozen water (the combined effect of the following processes: the upward migration of unfrozen water in a frozen active layer in the cold season; water migration and ice lensing in the frozen ground behind the freezing front during upward freezing; water migration and ice lensing in the still frozen ground beneath the thawing plane in the warm season). (3) Self-purification of ice. (4) Syngenetic growth of ground ice due to the addition of material onto the ground surface. (5) Annual repetition of the processes mentioned above. Thus, a new type of ground ice — repeated-segregation ice — is distinguished.