Rib-and-trough features in a tundra lake
This is a photo of rib-and-trough structures in a tundra lake in the Kaminak Lake area, southwestern Nunavut, Canada, west of Hudson Bay, 62 to 63° North latitude. The photo was taken from an altitude of ~50 m in August 1971. For an extensive discussion of these features see image 0120, which also cross-references 19 other images showing aspects of this type of patterned ground feature. In this image, note particularly the mud boils developed on diamicton on shore and the bifurcating, meandering shapes of the ribs. The ribs are covered by gravel and fine cobbles. Boulders up to half a meter in diameter fill the troughs. More regularly spaced, straight ribs that trend directly down slope, such as those shown in images 0120, 0127, and 0196, are more typical of the tundra lakes in this region. See detailed discussion for image 0240.
Updated 05/06/2010 AW