Activation of Hazardous Permafrost Processes in the North of West Siberia Under the Technogenic Impact and Climate Changes

Abstract:

The north of West Siberia continues to be intensively involved in economic development, primarily due to oil and gas mining and the growth of transport infrastructure including gas pipelines and seaports. Permafrost with widespread tabular ground ice and ice wedges, greatly complicates the economic activity. Modern climate warming leads to an increase in the temperature of permafrost and active layer thickness. The dynamics of changes in permafrost state under natural conditions with technogenic impact lead to an activation of permafrost processes, making them hazardous and catastrophic in relation to already existing infrastructure facilities. Thaw subsidence, retrogressive thaw slumps and erosion ravines are formed. A new permafrost phenomenon, gas emission craters, dangerous for the infrastructure is appeared.

On the sea coasts of West Siberia, vast spread ground ice bodies determine the landforms and rate of coastal destruction, which poses a threat to the coastal structures, existing and projected, including economic development in the area of Cape Kharasavey, the passage of the gas pipeline through the Baydaratskaya Bay (on the western coast of the Yamal Peninsula), operation of the port facilities of Sabetta (on the eastern coast of the Yamal Peninsula).

On Yamal and Gydan Peninsulas, there is an intensification of the retrogressive thaw slumps associated with the thawing of tabular ground ice. New retrogressive thaw slumps (thermocirques) appear, and a new cycle of activation is noted for the previously stabilized landforms. The high retreat rate of the icy walls poses a real danger to infrastructure facilities in the Arctic plains.

The natural rhythm of the development of relief-forming processes is superimposed on the technogenic impact, leading to the activation of the existing complex of permafrost processes and the appearance of new ones. In particular, on Tazovskiy and Yamal Peninsulas, the creation of linear infrastructure facilities leads to the redistribution of surface runoff and the intensive development of thermal erosion with ravines formation.

Supported by RFBR grant № 18-05-60080.