Soil Composition

When the snow above the active layer melts (the layer of soil where plants can grow), the water remains on the surface of the soil. This is because water cannot be absorbed by the permafrost (a permanent layer of frozen ground below the active layer), leaving the top layer of the soil wet and soggy. Evaporation of the water is also not possible because of the biome's cool climate. The arctic tundra landscape is formed by the freezing, thawing, and refreezing of this soggy soil. This type of land formation is only unique to the arctic tundra. There are five types of distinguishable land formations by the power of freezing water: pingos, frost boils, bumpy ground, polygons, and stripes. 

Pingo

Frost Boils

Polygon