New publication on retrogressive thaw slumps in saline permafrost in Northeast Greenland

Our study investigates how saline permafrost and complex local geology influence the behavior and morphology of retrogressive thaw slumps – slope failures in permafrost that occur when ice-rich sediments or massive ground ice are exposed. We focused on the influence of perennially unfrozen pockets within frozen ground below 0°C (cryopegs) on two retrogressive thaw slumps close to the Zackenberg Research Station, which were highly active between 2016 and 2020.
We showed that riverbank erosion during a flood event on the Zackenberg River in 2016 exposed massive ground ice and triggered the evolution of both thaw slumps. Electrical resistivity tomography, stratigraphic observations, temperature measurements and laboratory soil analyses helped confirm cryopegs within marine sediments. We hypothesize that cryopegs can slow slump retreat once they become dry, and that thaw slumps in saline permafrost may shift toward structures comparable to active layer detachment slides as retreat slows.

The direct link to our paper:
Eppinger, S., Lorentzen, T.H., Angelopoulos, M., Ingeman-Nielsen, T., Rudd, D.A., Marcer, M. & Krautblatter, M. (2026). Retrogressive Thaw Slump Morphology and Dynamics in Saline Permafrost in Northeast Greenland. Journal of Geophysical Research: Earth Surface, 131, e2025JF008848. https://doi.org/10.1029/2025JF008848.