Stone rings, pingoes, and rock glaciers and other periglacial activity became more common during ice ages.
Periglacial activity is a geomorphic process that occurs due to periodical defrosting of snow in regions of permafrost (frozen ground), the runoff which becomes frozen again in ice wedges and other structures. During periglacial activity, there is a regular fluctuation of air temperature across zero degree Celsius, and the process influences the landscape in a significant way.
<span>Enhanced Periglacial
Geomorphic processes resulting from seasonal thawing of snow in permafrost areas where the runoff refreezes in wedges, fissures, cracks and other structures. Periglacial areas can be enviroments where freezing and rethawing significantly restructure or modify the surrounding environment.</span>
