Estimating Rock Moisture Based on Ground Penetration Radar Survey in Frozen and Thawed States

Possibilities of estimating rock moisture based on ground penetrating radar data were considered. A methodology for estimating moisture of dispersed rocks has been proposed which uses an empirical formula based on the relative change of delay time $(\mathbf{N}_{\mathrm{t}})$ of GPR signals reflected from the medium interface in the frozen ($(\mathbf{t}_{\mathbf{M}}$., ns) and thawed ($(\mathbf{t}_{\mathbf{T}}$, ns) states. It was approbated in the natural environment., on two sites in Central Yakutia. GPR data within the active layer during the period of complete freezing and thawing of rocks was examined. On the first testing site., data values were selected from a section segment in the vicinity of the check hole. The average value of the signal delay time from the reference boundary at a depth of 1.7 m was calculated based on three adjoining sounding locations. The relative change of the signal delay time $\mathbf{N}_{\mathbf{t}}$ was evaluated. The average gravimetric water content was calculated according to the proposed formula. Moisture distribution along the GPR section on the second approbation site was also determined in accordance with the methodology. The proposed methodology enables remote evaluation of dispersed rock moisture and its changes under the influence of various natural and anthropogenic factors within the active layer of the cryolithozone rock massif.