Why do stone stripes form on steep slopes in permafrost areas?

Stone stripes form on steep slopes in permafrost areas due to the combination of intense freeze-thaw cycles and the influence of gravity on the soil's active layer.123

The process involves the following factors:

• Frost Action: Repeated freezing and thawing stir and sort granular sediments, causing coarser particles to move to the surface and arrange themselves by size.12
• Active Layer Dynamics: The "active layer" of soil above the permafrost becomes saturated and soggy during thaw periods. Because the underlying permafrost is impermeable, this waterlogged layer remains lubricated and prone to movement.123
• Downslope Motion: On steeper slopes, gravity causes this soggy, sorted material to move slowly downhill. This motion stretches circular stone rings and polygonal stone nets into elongated, parallel stone stripes.12

This phenomenon is a form of solifluction, where the saturated surface soil creeps downslope over the frozen substratum.23