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 debris-flows. 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 para-glacial system, though highlighting the need to locally refine the measurement network. In the present case, the destabilized front advances at ~1m/a and the upstream creeping part at ~0.4m/a. Variance analysis also provide objective thresholds that could be used to distinguish underlying physical processes.