Borehole logging in alpine permafrost, upper Engadin, Swiss Alps

• Published in: Permafrost and Periglacial Processes
• Main Authors: Mühll, Daniel S. Vonder, Holub, Petr
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1992
• Subjects: Earth-Surface Processes; Ice; permafrost; Permafrost and Periglacial Processes
• Online Access: http://dx.doi.org/10.1002/ppp.3430030209; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fppp.3430030209; https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.3430030209

Abstract In two boreholes through Alpine permafrost, borehole geophysical measurements were performed. At the borehole through rock glacier Murtèl‐Corvatsch, where cores were taken, the main difficulty was to fill up the hole with water. Consequently, only some of the logging methods could be applied. Nevertheless, gamma‐gamma log (and qualitatively also gamma‐ray) made it possible to obtain density and to calculate ice content. At the Pontresina‐Schafberg drill site, a complete set of logs was run in a water‐filled hole. The bedrock was reached at a depth of approximately 16 m. No cores were obtained by the air‐lift percussion technique. Logging measurements were done to determine thickness of the perennially frozen debris layer above the bedrock and to investigate P‐wave velocity, resistivity and ice content of the whole permafrost body. The boreholes at both drill sites show a high ice content layer (80–95 % by volume), although temperature characteristics are quite different.