Mudboils within poorly drained area ornamented by orthogonal frost polygons
Location:
Kaminak
Lake Area, Kivalliq, Nunavut, Canada
This is a typical image of terrain below marine limit (the area submerged in the post-glacial Tyrrell Sea), where low, poorly drained areas are covered by frozen peat, which fosters formation of frost polygons, and better-drained areas of fine-grained sediment are ornamented by mudboils (see discussion under images 0072 and 0240 and discussion in Shilts, 1974. In this particular image, it can be seen that several of the mudboils are active (see discussion under image 0240 ), and there appears to be smoke on the ground, indicating a minor tundra fire in progress (see discussion under image 0053). In the high-resolution image in the upper right quadrant, on a large polygon, there appears to be a small herd of caribou. Note that the boundaries of these unusual orthogonal polygons are marked by trenches containing standing water, probably resulting from melting of the ice wedges that formed there during this particularly hot, dry summer. I am uncertain of the reason I took this picture (from an altitude of about of 500 m), but it could have been the contrast in ground patterns, the caribou, the active mudboils, the orthogonal polygons, the fire, or all five features.
Updated 08/28/2009 CAB