ИСТИНА

In the fifties of the last century observations of permafrost temperatures were carried out by Kudryavtsev and Redozubov in the Northeast of the European part of Russia near Vorkuta city. Now we can compare their results and modern measurements started by MSU since 2010. It was expected that the global climatic changes in the end of 20th century may influence the thermal mode of soils. The territory of the area represents accumulative plain elevated up to 200 m above sea level. Quaternary deposits have considerable thickness of about 100 m. Relatively high-temperature permafrost occupes up to 80-90% of the territory on all elements of relief. Mostly permafrost thickness is about 40-80 m, and the maximum depth is about 200 m. Average annual temperatures of breeds change from-0,1 to -2 °C. Sites with permafrost distributed under active layer occupy 60-70% of the area on positive forms of relief. Average annual temperatures of soils in the area in general is from -0,1 to -2,0°C. Permafrost distributed from a certain depth below active layer is observed in dry depressions and in river valleys, its thickness is about 5-20 m. Active layer depth varies from 0,3 to 2,5 m. The observation site is located on a left bank of Vorkuta river (1,5 km from the river) elevated up to 100 m above sea level. Sixty years ago the area was the typical flat tundra with slight dry depressions of about 10 - 50 m wide. On the site permafrost is under active layer. At the moment as far as we can judge natural conditions are in the range described 60 years ago. According to thermometry in boreholes temperature of soils now is -0,4 -0,8°C up to the depth 15м, and it was about -1,0 -1,5°C sixty years ago. We did not found permafrost began below active layer. Location and sizes of taliks found sixty years ago are the same now. Thus, permafrost conditions on the site appear to be steadier with the climate changes than we could expect.