Ice wedge polygons
One of the most common forms of patterned ground in Arctic regions are ice wedge polygons. In winter the cold causes frozen soil to shrink, and cracks form (similar to drying mud). In spring meltwater seeps down into the cracks. It freezes and expands when it is chilled by the still-frozen soil. The frozen water forms wedges of ice in the soil. The ice wedges tend to increase in size year after year. I found these patterns by chance flying a drone over tundra. It is much harder to observe these polygons from ground level.
Ice wedge polygons
One of the most common forms of patterned ground in Arctic regions are ice wedge polygons. In winter the cold causes frozen soil to shrink, and cracks form (similar to drying mud). In spring meltwater seeps down into the cracks. It freezes and expands when it is chilled by the still-frozen soil. The frozen water forms wedges of ice in the soil. The ice wedges tend to increase in size year after year. I found these patterns by chance flying a drone over tundra. It is much harder to observe these polygons from ground level.