Coastal erosion at Western Yamal, Russia, under climate changes and anthropogenic impact

The coasts of the Kara Sea at a quarter of the coastline length are represented by the retreating thermoabrasional coasts composed by permafrost. Their dynamics is determined by hydrometeorological conditions (duration of the ice-free period, wave fetch, air and water temperature, wind direction and strength, etc.) and parameters of the coast (coastal sediments composition and ice content, the relief of the coastline and shallow waters area). The maximum rate of destruction of thermoabrasional coasts is typical for the Western coast of the Yamal Peninsula. Here in the area of the polar station Marre-Sale, the mean multiyear rates are 1.7-2 m per year, and in the area of Kharasavey settlement - 0.5-2.5 m per year. The rates of coastal retreat in the key areas of Western Yamal, obtained by different teams of researchers, were recalculated using a single method as for correct comparison of the retreat rates it is necessary to average the results of calculations for similar periods of time and for coastal segments of similar length along the coast. Analysis of coastal retreat rates allows us to identify both the contribution of climate change and anthropogenic impact. The Yamal Peninsula is home to Russia's largest natural gas fields, the development of which is reflected in the dynamics of the coastline. Analysis of multi-temporal aerial photos and space images on the coast near the Kharasavey gas condensate field allowed to trace the dynamics of the shores since 1972, both in undisturbed conditions and after the beginning of construction of the field infrastructure. The role of the technogenic factor at the rapidly retreating coastal segments has turned to be higher than the impact of changes in climatic parameters.

The work has been supported by the MK-398.2019.5 grant.