Brief communication: Alternation of thaw zones and deep permafrost in the cold climate conditions of the East Siberian Mountains, Suntar-Khayata Range

• Published in: The Cryosphere
• Main Authors: Sysolyatin, Robert, Serikov, Sergei, Kirillin, Anatoly, Litovko, Andrey, Sivtsev, Maxim
• Format: Text
• Language: English
• Published: 2023
• Subjects: permafrost
• Online Access: https://doi.org/10.5194/tc-17-4601-2023; https://tc.copernicus.org/articles/17/4601/2023/

The Suntar-Khayata Range includes numerous natural phenomena interacting with or depending on permafrost conditions. Here, we examine some patterns of deep permafrost and talik zones on adjacent sites. A 210 m deep borehole in siltstone bedrock was equipped for the temperature monitoring of the topmost 15 m and measurements of a deep permafrost temperature profile in July 2010. The temperature curvature in the upper part has a bend, which is consistent with the upper portion justified by climate warming, and shows a steady-state linear geothermal profile below 85 m depth with a high geothermal heat flux. A shallow borehole situated at the river floodplain was used to investigate the thaw zone's temperature regime. The temperatures down to 6.7 m deep have been monitored at 5 min intervals during heavy rainfall, and the temperature readings have behaved quite peculiarly. The thickness of the seasonal freezing layer reaches 5.7 m; moreover the ground temperature increases to 6 ∘ C at 6.7 m depth by groundwater heat transfer. This study provides some new insights into the permafrost condition at one of the coldest places in the Northern Hemisphere.