Radiation Parameters Of The Peat Bog Due To Permafrost Conditions Variations: A Case Study Of The Oma River Basin Of The Nenets Autonomous Okrug, Northwest Of Russia

The purpose of this article is to examine the distribution of natural radionuclides as well as the gamma radiation flux due to the variations of soil seasonal thawing depth. The study was conducted at a lumpy peat bog located within the catchment area of the Oma River, located within the Nenets Autonomous Okrug of Russia. The site was selected due to the presence of an active layer (AL) with varying depths of thawing, as well as the warming effect of the river. This feature enabled an initial assessment of the impact of thawing depth on radon flux, gamma radiation, and the distribution of other natural radionuclides along the peat profile. Field observations revealed that permafrost deposits act as a barrier to the intake of 222 Rn from geological layers. The relationship between alterations in radiation parameters (gamma radiation flux, radon flux density (RFD), radionuclide composition of peat) and the thickness of the AL has been established. An increase in gamma radiation levels and RFD has been observed in areas exhibiting maximum seasonal thawing of the seasonally thawed layer. The correlation coefficients were found to be 0.70 and 0.83, respectively. The analysis of peat profiles in diverse permafrost settings revealed that in regions exhibiting deeper thawing of soil, there is an abundance of 210 Pb relative to the concentration of its progenitor radionuclide, 226 Ra. The observed excess of 210 Pb may be attributed to radon flux from deeper geological layers.