jääjuuriseen

Jääjuuriseen is a Finnish term that translates literally to "ice root" or "ice burrow." It refers to a natural phenomenon observed in frozen soil where water seeps upwards through capillary action, freezing upon contact with the sub-zero surface. This process creates needle-like ice formations, often called "ice needles" or "ice columns," that can push up soil particles and plant material.

These ice formations are fragile and typically melt quickly once temperatures rise above freezing. However, their formation can have a noticeable impact on the surface of the ground, particularly in areas with fine-grained soils and a significant amount of available moisture. Jääjuuriseen is most commonly observed in the spring or autumn when temperatures fluctuate around the freezing point.

The extent and visibility of jääjuuriseen depend on several factors, including soil type, moisture content, and the rate of freezing and thawing. In some cases, these ice needles can be quite pronounced, creating a delicate and ephemeral landscape. While the term itself is Finnish, the phenomenon of ice needle formation is recognized in periglacial environments worldwide. It is a demonstration of frost heave, a broader process by which the expansion of freezing water in the ground lifts the soil.