Detecting retrogressive thaw slumps using single-pass bistatic TanDEM-X observations

Vast areas of the Arctic host ice-rich permafrost, which is becoming increasingly vulnerable to rapid thaw in a warming climate. When ice-rich permafrost soil thaws it becomes unstable, leading to changes in the topography. The most rapid and dramatic changes occur due to retrogressive thaw slumps. These slumps evolve by a retreat of the slump headwall during the summer months, making them detectable by comparing digital elevation models over time. Here we present first results of a retrogressive thaw slump detection method using bistatic single-pass radar observation from the TanDEM-X satellite pair over the time span from 2011 to 2017. Our processing chain include the digital elevation generation process, elevation model differencing, water body mask generation and a method for the detection of significant height changes. We detected 157 active RTS validated by high- to medium-resolution optical data in our study region (3700 km
²
) located in the Mackenzie River Delta, Northwest Territories, Canada.