A Century (1910–2008) of Change in a Collapsing Pingo, Parry Peninsula, Western Arctic Coast, Canada

An isolated, eroding pingo at the southern end of Parry Peninsula, N.W.T., Canada was first photographed in about 1910. The photograph allows examination of a century of landform change. Since 1910, the pingo crater pond has drained, the north side of the pingo has become well vegetated, the serrated crest has been smoothed, and the lake bottom has become colonised by willows and other vegetation. The height of the feature was over 100 ft (30 m) in 1910 and is now about 50 ft (15–17 m). The erosion of the pingo has probably been dominated by the strong southerly katabatic winds in the area, as the vegetation on the south side of the pingo is poorly developed in comparison with the north side. A secondary cause of erosion has been the numerous excavations by ground squirrels (Spermophilus parryii) and foxes (Vulpes lagopus) on the slopes of the pingo. It is unusual to detect change of collapsed pingos near the western Arctic coast of Canada unless ground ice is exposed in the core or on the sides of the pingo. The increases since 1996 in height and cover of willows are the first record of such change from western Arctic Canada. Copyright © 2011 John Wiley & Sons, Ltd.