New geophysical methods of investigating the nature and distribution of mountain permafrost with special reference to radiometry techniques

• Published in: Permafrost and Periglacial Processes
• Main Authors: Mühll, Daniel Vonder, Hauck, Christian, Gubler, Hansueli, McDonald, Robert, Russill, Nick
• Other Authors: EU Environment and Climate Research Programme
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2001
• Subjects: Earth-Surface Processes; permafrost; Permafrost and Periglacial Processes; pergélisol
• Online Access: http://dx.doi.org/10.1002/ppp.382; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fppp.382; https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.382

Abstract A series of geophysical surveys were undertaken within the PACE geophysical work package. Various methods were applied including refraction seismics, DC resistivity, ground penetrating radar (GPR), electromagnetic induction, radiometry and bottom temperature of snow cover (BTS). The focus of the surveys was to determine the internal structures and distribution of mountain permafrost. This paper gives a preliminary overview of progress. The two‐dimensional DC resistivity tomography combines the geoelectrical sounding and mapping and makes it possible to model internal structures. This method was applied at all PACE drill sites. Electromagnetic induction methods showed good results, in particular the EM‐31 for determining the permafrost distribution and the PROTEM to assess the overall permafrost thickness. A major new development discussed here is the use of passive microwave (11.4 GHz) for airborne remote measurement of the bottom temperature of snow cover (BTS). Manual BTS measurements agreed very well with the BTS determined by radiometry. To reduce ambiguity, several geophysical methods should be deployed at the same locality. As a further step, such measurements could be interpreted using joint inversions. Copyright © 2001 John Wiley & Sons, Ltd. RÉSUMÉ Une série de levés géophysiques a été réalisé dans le cadre des travaux de PACE. Différentes méthodes ont été utilisées y compris la séismique réfraction, la résistivité DC, le radar pénétrant le sol (GPR), l'induction électro‐magnétique, la radiométrie et la température à la base de la couverture nelgeuse (BTS). Le but de ces levés était de déterminer les structures internes et la distribution du pergélisol de montagne. Le présent article donne une vue générale préliminaire des progrès réalisés. La tomographie en deux dimensionns par résistivité. DC qui combine le sondage géoélectrique et la cartographie, rend possible la reconnaissance des structures internes. Cette méthode a été appliquée dans tous les sites de sondage. Les méthodes par ...