patternedground

Patterned ground refers to naturally occurring geometric patterns that emerge in the landscape in regions with permafrost. These patterns are created by the cycles of freezing and thawing of the ground. The most common patterns include polygons, circles, nets, stripes, and cubes.

The formation of patterned ground is a process driven by frost action. Repeated freezing and thawing of soil causes the expansion and contraction of water within it. In areas with poor drainage and suitable soil types, this can lead to the sorting of soil particles. Larger stones and rocks tend to move towards the edges of the patterned areas, while finer materials like sand and silt accumulate in the center. This sorting process is what creates the distinct shapes observed.

Polygonal patterns are often found in flatter areas and are characterized by polygonal outlines formed by raised ridges of stones or ice wedges. Circular patterns can occur on slopes and are thought to result from a combination of frost heave and downslope movement of material. Striped patterns are typically found on gentle slopes, where material is sorted into linear bands aligned with the contour of the land.

Patterned ground is a significant indicator of permafrost and is a common feature in arctic, subarctic, and alpine environments. The specific type and scale of patterned ground can vary depending on factors such as climate, soil composition, slope, and moisture content. These features are studied by geomorphologists to understand past and present environmental conditions.