Effects of tundra fire on mudboils (nonsorted circles) two years after the fire

Location: Kaminak Lake area, Kivalliq, Nunavut, Canada; approximately 62° 02' N; 95° 30' W

This photo, taken from an altitude of about 20 m, shows the results of a tundra fire about two years after the event. Once the turf that originally surrounded these mudboils (nonsorted circles) was burned away, and the resulting ash washed away by rain and melting over a two-year period, boulders that were originally concealed by the turf stand out and form stone rings (sorted circles). The boulders, frost-heaved to the mudboil's surface, are rafted laterally to the mudboil's rim by the extrusion of sediment by diapiric processes that form and maintain the circular shape (see extended explanation under image 0240 ; diagram under image 0098). Note that vegetation is beginning to reestablish itself with what appear to be grasses sprouting in the mudboil fringes. This is probably in area of Fire #5, between Kaminak and Carr Lakes (see image 0101).

Updated 04/07/2010 AW