Rapid Changes in Retrogressive Thaw Slump Dynamics in the Russian High Arctic Based on Very High‐Resolution Remote Sensing

Abstract We used very high‐resolution satellite images to map the development of retrogressive thaw slumps (RTS) at six sites in the Russian High Arctic for the period 2011 to 2020. The 3,466 mapped RTS revealed an overall high activity, with site‐specific increases of RTS‐affected area up to +2,700% and RTS numbers up to +1,294%. For coastal sites, the changes in RTS‐affected area were mutually influenced by thermal abrasion at the bluff base and thermal denudation at the headwall. Overall, we observed strong erosion with average annual headwall retreat rates reaching up to −6.3 m/yr and bluff base retreat rates up to −5.2 m/yr. Similar to prior studies from the Canadian High Arctic, our findings suggest a rapid degradation response of ice‐rich permafrost in the rapidly warming Russian High Arctic.