Concept

Avalanche

Publications associées (178)

Wind tunnel experiments: cold-air pooling and atmospheric decoupling above a melting snow patch

Michael Lehning, Enrico Paterna, Philip Crivelli

The longevity of perennial snowfields is not fully understood, but it is known that strong atmospheric stability and thus boundary-layer decoupling limit the amount of (sensible and latent) heat that can be transmitted from the atmosphere to the snow surfa ...

Copernicus GmbH2016

A new ring‐shaped wind tunnel facility to study wind‐packing of snow.

Michael Lehning, Christian Gabriel Sommer, Charles Fierz

A new wind tunnel was designed and built at SLF. The facility is ring-shaped to simulate an infinite fetch. This is important for experiments where the observed processes have a slow time scale (minutes to hours). The wind tunnel was developed to study the ...

University de Genève2016

A new mechanical framework to interpret weak layer and slab fracture in the propagation saw test

Johan Alexandre Philippe Gaume, Lorenzo Benedetti

This work aims to provide a mechanical model for the Propagation Saw Test (PST) based on the Euler-Bernoulli beam, allowing a description of the slab and weak layer stress states in the quasi-static regime. We assume an elastic-perfectly brittle model as c ...

2016

Parental arc magma compositions dominantly controlled by mantle-wedge thermal structure

Stéphane Laurent Escrig

The processes that lead to the fourfold variation in arc-averaged compositions of mafic arc iavas remain controversial. Control by the mantle-wedge thermal structure is supported by chemical correlations with the thickness of the underlying arc crust(1-3), ...

Nature Publishing Group2016

Attenuation of wind-induced pressure perturbations in alpine snow

Wolf Hendrik Huwald, Marc Parlange, Chad Higgins

Windpumping has been identified as a process that could potentially enhance sublimation of surface snow at high forcing frequency and spawn air movement deeper in firn at lower frequencies. We performed an experiment to examine the relationship between hig ...

International Glaciological Society2016

Sensitivity of Alpine3D modeled snow cover to modifications in DEM resolution, station coverage and meteorological input quantities

Michael Lehning, Mathias Thierry Pierre Bavay, Sebastian Schlögl

This study presents a comprehensive sensitivity and uncertainty assessment of important input parameters on the Alpine3D modeled snow water equivalent (SWE) for two different alpine catchments. Horizontal resolution of the DEM grid, station coverage and se ...

Elsevier2016

Influence of snow cover properties on avalanche dynamics

Walter Steinkogler

Snow avalanches are a direct thread to many mountain communities around the world and already small avalanches can endanger traffic routes and result in loss of life or property. Their destructive power depends, among other things, on the overall mass and ...

EPFL2015

A new mixed-mode failure criterion for weak snowpack layers

Johan Alexandre Philippe Gaume

The failure of a weak snow layer is the first in a series of processes involved in dry‐snow slab avalanche release. The nature of the initial failure within the weak layer is not yet fully understood but widely debated. The knowledge of the failure criteri ...

2015

Thermal energy in dry snow avalanches

Michael Lehning, Walter Steinkogler

Avalanches can exhibit many different flow regimes from powder clouds to slush flows. Flow regimes are largely controlled by the properties of the snow released and entrained along the path. Recent investigations showed the temperature of the moving snow t ...

Copernicus Gesellschaft Mbh2015

Influence of weak layer heterogeneity and slab properties on slab tensile failure propensity and avalanche release area

Johan Alexandre Philippe Gaume

Dry-snow slab avalanches are generally caused by a sequence of fracture processes, including failure initiation in a weak snow layer underlying a cohesive slab followed by crack propagation within the weak layer (WL) and tensile fracture through the slab. ...

2015

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