Process oriented use of geostatistics to analyse creeping para‐glacial features

Abstract

Complex para-glacial systems may show signs of destabilization leading to frequent and potentially hazardous debrisflows. Understanding creeping permafrost displacement over a period of time is therefore crucial for hazard management and risks assessment. This paper presents our methodology for estimating creeping permafrost displacement based upon data derived from various survey methods and demonstrates its relevance on the Glacier Bonnard system in southern Switzerland. Geostatistical processing allowed estimation of the displacement intensity over the area of interest, as well as assessment of the interpolation quality. Although the local measurement network needs to be refined, the results largely improve the understanding of the Bonnard paraglacial system, though highlighting the need to locally refine the measurement network. In the present case, the destabilized front advances at~1 m/a and the upstream creeping part at~0.4 m/a. Variance analysis also provide objective thresholds that could be used to distinguish underlying physical processes.

Detection and Analysis of Ground Deformation in Permafrost Environments

“…Rock glaciers are prominent moving periglacial landforms (Barsch, ; Kääb, ). Their deformation is often on the order of decimetres to metres per year (Delaloye et al, ; Bardou et al, ; Schoeneich et al, ) and data from the few rock glaciers where deformation monitoring has been carried out at depth seem to suggest that most of the deformation occurs in a concentrated shear zone in the centre or close to the base of permafrost (Arenson et al, ; Merz et al, ). Gravity‐driven creep is the dominant mechanism for rock glacier deformation (Harris et al, ).…”