Temperature Field of the Permafrost Zone in Northeastern Siberia

• Published in: IOP Conference Series: Earth and Environmental Science
• Main Authors: Spektor, V B, Shestakova, A A, Torgovkin, Ya I
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: IOP Publishing 2020
• Subjects: Okhotsk; lena delta; permafrost; Siberia
• Online Access: http://dx.doi.org/10.1088/1755-1315/459/3/032032; https://iopscience.iop.org/article/10.1088/1755-1315/459/3/032032/pdf; https://iopscience.iop.org/article/10.1088/1755-1315/459/3/032032

Abstract The Northeastern Siberia includes the coasts of the Sea of Okhotsk, part of the North Siberian Lowland, the Central Siberian Plateau and the Lena Delta. Based on field measurements and calculations, this study characterizes the regional distribution of permafrost temperature in the layer of zero annual amplitude (ZAA). Permafrost temperatures vary over a wide range from -2 to -13°C. Analysis of ZAA temperatures indicates that permafrost is transient in much of the study region. In its northern part, especially where diluvial deposits are present, temperature profiles are isothermal or have inverse (negative) gradients. The temperature field in the areas of pre-Quaternary carbonate rocks is characterized by wide scatter of the values and often by higher ZAA temperatures. This is due to the karst process in carbonate rocks which is associated with heat release. This process likely occurred below the bottom of post-catastrophic basins, resulting in greater heat flow and disturbance of the equilibrium state of permafrost. The layers of dolomite flour over the pre-Quaternary carbonate rocks provide additional evidence of the high water contents in upper permafrost during deposition of the diluvial sequence. Temperatures below ZAA in these areas may reach -4°C, while similar settings without carbonate rocks have temperatures below ZAA as low as -8 to -11°C. This study has confirmed the high variability of ZAA temperatures in the region.