Recently extinguished tundra fire in area of mudboils
This plain, with scattered bedrock outcrops projecting through a cover of glacial till, is densely ornamented with mudboils, which are also called nonsorted circles by other authors. The original photo, taken at about 300 meters altitude, shows that the turf rims surrounding the mudboils have burned out, leaving the mudboils rimmed by a significant deposit of ash. See images 0058, 0101, and 0107 or similar examples of the impact of fire on mudboil borders. Images 0102, 0103, and 0106 show stone rings surrounding burned out mudboils. These boulders, heaved by frost to the surface and pushed to the mudboil's rim by diapiric processes (Shilts, 1978; image 0098), are normally obscured by vegetation and often appear once the turf is burned, and ash is washed away. Images 0237, 0238, and 0239 show unburnt mudboils surrounded by turf rings similar to those that were destroyed by fire in this image. The stone rings around mudboils in image 0232 may have been created by an ancient fire, but certainly not by any of the fires that burned during the hot, dry summer of 1973. See detailed discussion for image 0240.
Updated 05/06/2010 AW