palsa bog Boggy tundra, in which ground ice is partly responsible for the formation of peat hummocks up to 35 m long, 15 m wide, and 7 m high. Palsa bogs have a core of frozen peat and develop cyclically. The dark surface with pools of water provide insulation and prevent snow from lying, causing the bog to grow; it develops a cover of lichen, giving it a high albedo; it erodes as the surface becomes unstable; the erosion reveals peat, which is dark and reduces the albedo, causing the bog to warm, leading to melting; a pool forms and the sequence begins again. Palsa bogs are circumpolar in distribution and are apparently subfossil.

palsa bog Boggy tundra, in which ground ice is partly responsible for the formation of peat hummocks up to 35 m long, 15 m wide, and 7 m high. They are circumpolar in distribution and are apparently subfossil features which are now being degraded.