Increasing rates of retrogressive thaw slump activity in the Mackenzie Delta region, N.W.T., Canada

Climate warming at high latitudes may be contributing to the increase in areal extent of terrain disturbance associated with thawing permafrost. To evaluate change over time we analyzed historical temperature records and mapped retrogressive thaw slumps in the Mackenzie delta region using 1950, 1973 and 2004 aerial photographs. Here we show that rates of retrogressive thaw slump activity from 1973–2004 were significantly greater than during the preceding period (1950–1973) and suggest that these changes have occurred in response to a significant warming of annual and summer air temperatures during the period of record. In rolling, ice‐rich terrain, the rate of thaw slump activity can be expected to increase with continued climate warming. The impacts of slumping on landscape evolution and soil and lake chemistry will likely magnify the direct effects of warming on terrestrial and aquatic ecosystems.