Polythermal glaciers

Polythermal glaciers are those glaciers that have a mixed basal thermal regime. They have warm ice (at 0°C) in their interior where the ice is thick and is warmed to the pressure melt point, and cold ice (below 0°C) around their margins where ice is thin and on their surface. They have a restricted geographical range and are particularly common in the Arctic, suggesting that there are climatic controls on their distribution. Proglacial and englacial thrusting, folding, and deformation of the ice are common during glacier flow, as is the deformation of permafrost in proglacial areas.