Monitoring rock freezing and thawing by novel geoelectrical and acoustic techniques ...

• Main Authors: Murton, Julian B., Kuras, Oliver, Krautblatter, Michael, Cane, Tim, Tschofen, Dominique, Uhlemann, Sebastian, Schober, Sandra, Watson, Phil
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2016
• Subjects: permafrost
• Online Access: https://dx.doi.org/10.3929/ethz-b-000124934; http://hdl.handle.net/20.500.11850/124934

Automated monitoring of freeze‐thaw cycles and fracture propagation in mountain rockwalls is needed to provide early warning about rockfall hazards. Conventional geoelectrical methods such as electrical resistivity tomography (ERT) are limited by large and variable ohmic contact resistances, requiring galvanic coupling with metal electrodes inserted into holes drilled into rock, and which can be loosened by rock weathering. We report a novel experimental methodology that combined capacitive resistivity imaging (CRI), ERT, and microseismic event recording to monitor freeze‐thaw of six blocks of hard and soft limestones under conditions simulating an active layer above permafrost and seasonally frozen rock in a nonpermafrost environment. Our results demonstrate that the CRI method is highly sensitive to freeze‐thaw processes; it yields property information equivalent to that obtained with conventional ERT and offers a viable route for nongalvanic long‐term geoelectrical monitoring, extending the benefits of ... : Journal of Geophysical Research: Earth Surface, 121 (12) ...