Journal: Permafrost and Periglacial Processes

Abbreviation

Permafr. periglac. process.

Publisher

Wiley

Journal Volumes

ISSN

1045-6740
1099-1530

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Publications 1 - 10 of 22
  • Creep of Alpine permafrost, investigated on the Murtèl Rock Glacier
    Item type: Journal Article
    Wagner, Stephan (1992)
    Permafrost and Periglacial Processes
    Borehole and surface deformation measurements from an active rock glacier in the eastern Swiss Alps are presented and analysed. Borehole deformation was measured by slope indicator and magnetic rings. Analysis of these measurements reveal two layers which behave quite differently. The upper, highly supersaturated (i.e. ice) layer undergoes steady-state creep (corresponds to a surface velocity of 5.5 to 6.0 cm/yr), overriding a non-deforming lower layer of saturated (structured) permafrost. Seventy-five per cent of the deformation takes place in a weak transitional zone, in the middle of the permafrost. Geodetic surveying shows, in contrast to the borehole measurements, a velocity variation in time by a factor of two. A constitutive law (Glen's flow law) was applied and the viscosity ratio between the upper ice layer and the weak transition zone was determined.
  • How rock glacier hydrology, deformation velocities and ground temperatures interact: Examples from the Swiss Alps
    Item type: Journal Article
    Kenner, Robert; Pruessner, Luisa; Beutel, Jan; et al. (2020)
    Permafrost and Periglacial Processes
  • A Labeling Intercomparison of Retrogressive Thaw Slumps by a Diverse Group of Domain Experts
    Item type: Journal Article
    Nitze, Ingmar; Van der Sluijs, Jurjen; Barth, Sophia; et al. (2025)
    Permafrost and Periglacial Processes
    Deep-learning (DL) models have become increasingly beneficial for the detection of retrogressive thaw slumps (RTS) in the permafrost domain. However, comparing accuracy metrics is challenging due to unstandardized labeling guidelines. To address this, we conducted an experiment with 12 international domain experts from a broad range of scientific backgrounds. Using 3 m PlanetScope multispectral imagery, they digitized RTS footprints in two sites. We evaluated label uncertainty by comparing manually outlined RTS labels using Intersection-over-Union (IoU) and F1 metrics. At the Canadian Peel Plateau site, we see good agreement, particularly in the active parts of RTS. Differences were observed in the interpretation of the debris tongue and the stable vegetated sections of RTS. At the Russian Bykovsky site, we observed a larger mismatch. Here, the same differences were documented, but several participants mistakenly identified non-RTS features. This emphasizes the importance of site-specific knowledge for reliable label creation. The experiment highlights the need for standardized labeling procedures and definition of their scientific purpose. The most similar expert labels outperformed the accuracy metrics reported in the literature, highlighting human labeling capabilities with proper training, site knowledge, and clear guidelines. These findings lay the groundwork for DL-based RTS monitoring in the pan-Arctic.
  • Gravimetrical investigation of ice-rich permafrost within the Rock Glacier Murtèl-Corvatsch (Upper Engadin, Swiss Alps)
    Item type: Journal Article
    Vonder Mühll, Daniel; Klingelé, Emile E. (1994)
    Permafrost and Periglacial Processes
    A gravimetrical study was carried out in the area of the Murtèl‐Corvatsch rock glacier in order to check the applicability of this method in alpine permafrost. The residual anomaly observed after removal of the linear regional trend is up to −1.5 mgal. Cores of borehole 2/1987 through this rock glacier showed a very high ice content in the uppermost 30 m. Borehole geophysical measurements furnished the density distribution with depth at the drill site showing values of less than 1000 kg m−3. According to the core stratigraphy and the density log at the drill site four layers were distinguished: an active layer to 3 m depth; massive ice (3–20 m); an ice‐silt‐sand layer (20–30 m); and a layer with ice‐saturated blocks (30–50 m). The extension of the four distinguished layers is modelled in three dimensions for the entire rock glacier according to the gravity data. The bedrock underneath the creeping permafrost is bowl‐shaped.
  • Analysing the creep of mountain permafrost using high precision aerial photogrammetry: 25 years of monitoring Gruben Rock Glacier, Swiss Alps
    Item type: Journal Article
    Kääb, Andreas; Haeberli, Wilfried; Gudmundsson, Gudmundur H. (1997)
    Permafrost and Periglacial Processes
    Aerophotogrammetrical monitoring of Gruben rock glacier over the period 1970 to 1995 results in a unique time series documenting the three‐dimensional surface kinematics of creeping mountain permafrost. In places, the area under study is affected by historical fluctuations of the polythermal Gruben glacier. Changes in elevation and surface velocities were measured over five consecutive five‐year periods using an advanced photogrammetric monoplotting technique of multitemporal stereo models. The measurements are based on a regular grid with a mesh width of 25 metres and have an accuracy of a few centimetres per year. Although surface lifting occurred in places and within individual time intervals, surface subsidence predominated at an average rate of a few centimetres per year in the ‘periglacial’ part of the rock glacier and of a few decimetres per year in the ‘glacier‐affected’ part of the rock glacier which still contains some dead glacier ice in permafrost. Fluctuations in horizontal surface velocities seem to correlate with temporal changes in surface elevation. Analysing flow along principal trajectories and interpreting the advance rate of the front leads to an age estimate of the rock glacier of a few millennia. Dynamic effects of three‐dimensional straining within the creeping permafrost as computed from the measured surface velocity field are estimated to potentially contribute to surface heave or subsidence in the same order of magnitude as the observed vertical changes. Temporal variations of surface altitudes at Gruben rock glacier show distinct similarities with mass balance and surface altitude variations determined on nearby glaciers but at a greatly reduced amplitude. This similarity may indicate that the same climatic forcing (summer temperatures?) could possibly have a predominant influence on permafrost aggradation/degradation as well as on glacier mass balance in mountain areas. © 1997 John Wiley & Sons, Ltd.
  • Permafrost creep and rock glacier dynamics
    Item type: Journal Article
    Haeberli, Wilfried; Hallet, Bernard; Arenson, Lukas; et al. (2006)
    Permafrost and Periglacial Processes
  • A model of potential direct solar radiation for investigating occurrences of mountain permafrost
    Item type: Journal Article
    Funk, Martin; Hoelzle, Martin (1992)
    Permafrost and Periglacial Processes
    A model is described to compute the daily potential direct solar radiation on the basis of digital terrain models. This model is a useful tool for investigating distribution patterns of permafrost in mountain areas. An example of its application to a low-altitude permafrost site in the Northern Prealps of Switzerland is presented.
  • Permafrost research sites in the Alps: Excursions of the Int. Workshop on Permafrost and Periglacial Environments in Mountain Areas
    Item type: Journal Article
    Haeberli, Wilfried; Evin, Michèle; Tenthorey, Geneviève; et al. (1992)
    Permafrost and Periglacial Processes
  • Construction, environmental problems and natural hazards in periglacial mountain belts
    Item type: Journal Article
    Haeberli, Wilfried (1992)
    Permafrost and Periglacial Processes
    Experience with man-induced permafrost problems in periglacial mountains has increased during recent years. Such problems can be local, as in the case of building foundations on ice-bearing ground, or can affect larger areas, as in the case of ski-run preparation on perennially and seasonally frozen ground. The most severe natural hazard concerns the destabilization, erosion and displacement by debris flows of loose, non-frozen material or weak bedrock on steep slopes. Such flows often take place as a consequence of glacier retreat or permafrost degradation and relate to atmospheric warming, which may continue or even accelerate in the future. The greatest drawback in man's behaviour with respect to these problems remains the ignorance of mountain permafrost. This probably originates from the fact that permafrost is not directly visible and, hence, is often not considered in the planning stage. The most important progress with respect to construction technology, environment protection and hazard mitigation in periglacial mountain belts can be achieved by improving communication and sharing of experience among scientists and technicians.
  • Permafrost changes in rock walls and the retreat of alpine glaciers: A thermal modelling approach
    Item type: Journal Article
    Wegmann, Matthias; Gudmundsson, Gudmundur H.; Haeberli, Wilfried (1998)
    Permafrost and Periglacial Processes
    The shrinkage of Grosser Aletschgletscher changed the thermal and mechanical boundary conditions in its marginal rock walls. The temperature at the glacier bed is at the pressure melting point while the exposed rock surface (above the glacier) is subject to atmospheric conditions. At our study site, a north‐facing rock wall at Konkordiaplatz, the surface temperatures have cooled below the freezing point during glacier retreat. Sensitivity studies on the thermal evolution and the permafrost dynamics in the bedrock involve heat transfer models with changing glacier surface and rock surface temperatures. They indicate that even small amounts of moisture limit the permafrost dynamics to the surface decametres at secular time scale. The calculations further indicate that, in the investigated rock wall, permafrost is penetrating as a consequence of the glacier retreat. The delay of the response of the permafrost base is in the order of millennia. Freezing and thawing of rock moisture leads to frost damage. The model results predict areas of frost shattering in the surface decametres and in the region of the permafrost base. The frost action is also favoured by unloading during glacier recession. © 1998 John Wiley & Sons, Ltd.
Publications 1 - 10 of 22