Dynamics, distribution and climatic conditions of retrogressive thaw slumps development in the western part of the Yamal Peninsula (2007—2023)

Retrogressive thaw slumps (RTSs) pose a significant hazard during the development of oil and gas fields on the Yamal Peninsula. The authors determine the dynamics and spatial distribution of retrogressive thaw slumps in the western part of the peninsula using multi-temporal highly detailed space images. They have established that large-scale activation of thermodenudation in this region occurs only in certain years under a unique or rather rare combination of natural and anthropogenic conditions. Having analyzed the archive of urgent meteorological observations at Marresale station for the last 55 years the researchers have identified the key combination of climatic conditions that contribute to the wide development of landslide processes. Such a combination is the early and stable onset of a warm period, elevated air temperatures and precipitation during the summer months (with a steady trend of their increase). The study has contributed to the development of a climatic index of the thermodenudation development risk (CPORT or TDRCI) that takes into account the duration of the period of active temperatures and the sum of precipitation during the warm period of the year. The proposed index unambiguously reflects both extreme retrogressive thaw slumps events in Yamal in 1989 and 2012. In the future, it is possible to validate the index using other northern regions of Western Siberia as an example. A coordinated accounting of meteorological observation data, morphometric parameters of the relief and features of the sheet ice spatial distribution in a given territory creates prerequisites for the practical implementation of a system of monitoring and forecasting the intensity of retrogressive thaw slumps’ development both at the regional and local levels of individual industrial objects.