DYNAMICS OF PERMAFROST HEAVING HILLS IN THE SOUTHERN PERMAFROST ZONE OF WESTERN SIBERIA

Abstract

The article presents an analysis of the annual dynamics of the temperature regime of the permafrost heaving mound in the southern permafrost zone of the West Siberian Plain. The study area belongs to the Tagrinskoye oil and gas field. The use in the study of the data of the automatic measuring system of temperatures within the heaving mounds made it possible to record the following parameters in time: temperature and moisture of the air at an altitude of 2 m, temperature and moisture of the soil at different depths. Modern automatic systems that record temperature data in permafrost make it possible to monitor changes in permafrost processes and predict undesirable technogenic hazards. The temperature regime of the permafrost heaving mounds is differentiated into an active layer with the dynamics of positive and negative temperatures and into the core of the heaving mounds, where long-term negative temperatures remain. Temperature study in permafrost is an important engineering and geological data that allows assessing the plasticity of permafrost in heaving mounds. It was determined that the active layer at a depth of 0,3-0,6 m has the highest dynamics of thawing and freezing, which refers to seasonal thawing. Permafrost rocks are plastic-frozen rocks, since at a depth of 1,6 m the temperature of permafrost increased to -0,3 °C and at a depth of 3 m it is underlain by melted sand with an average temperature of 0,66 °C. The dynamics of geomorphological changes depends on a complex of factors: the amount of precipitation in the summer-autumn period, the transition to zero temperatures and the amount of snow in the autumn-winter period.