Palsa

A palsa is a peat mound with a permanently frozen core of peat and mineral soil, forming in the polar and subpolar zones of discontinuous permafrost, an area that also covers what is sometimes separately called a permafrost plateau. Palsas typically have steep slopes rising above the surrounding mire surface, a shape that causes wind to strip snow from their summits while depositing it on the slopes and adjacent flats. They can grow up to 150 meters across and 12 meters high, and their internal thermal properties let them persist even where the mean annual temperature sits just below freezing.