Time-lapse GPR Measurements for Observing Shallow Cryo-Hydrogeological Borders in Spitsbergen's Fuglebekken Catchment

This study investigates the changes in shallow cryo-hydrogeological layers over time using Ground Penetrating Radar (GPR) in the unique Arctic environment of the Fuglebekken catchment on Spitsbergen Island. Accurate identification of permafrost changes is essential for understanding geotechnical and environmental processes, making precise monitoring imperative. GPR has proven to be a valuable non-destructive method, providing high-resolution spatially distributed data in permafrost regions and overcoming environmental limitations inherent in Arctic areas.

Utilizing a 250 MHz shielded antenna, GPR measurements facilitated the identification of the groundwater layer and changes in the top border of permafrost at different seasons in the Fuglebekken catchment. A distinctive aspect of this research involved the repetition of GPR profiles at the same location during three different seasons, enabling the observation of temporal variations in subsurface conditions across different seasons. These profiles were complemented by strategically placed boreholes and piezometers recording ground temperature at various depths and groundwater levels, providing key data for the validation and correlation of GPR results. Additionally, drone-based digital elevation models (DEM) were employed during GPR data processing to enhance the accuracy of results.

In the majority of recorded profiles, GPR measurements captured well-defined reflections of subsurface features. The emphasis is on revealing changes over time in the study area by distinguishing geological structures from the groundwater and upper permafrost boundaries. The study convincingly demonstrated the efficacy of GPR in capturing underground time-lapse changes throughout the studied area. The comprehensive insights gained through GPR offered distinct advantages over traditional methods reliant on limited borehole data, especially in terms of demonstrating spatial changes. Integration of GPR data with ground temperature measurements from boreholes and the use of Drone-based DEM during data processing provided a holistic perspective on the evolving nature of permafrost borders, significantly enhancing the accuracy and reliability of the findings.

Comprehending spatial and temporal variations in permafrost borders is critical for predicting the impacts of climate change and guiding geotechnical and environmental management strategies. This research serves as a valuable reference for future studies aiming to explore permafrost conditions in polar regions, offering a comprehensive framework for more effective monitoring and management practices.