Personne

Alec van Herwijnen

Publications associées (11)

Using video detection of snow surface movements to estimate weak layer crack propagation speeds

Johan Alexandre Philippe Gaume, Bertil Trottet, Alec van Herwijnen

Dry-snow slab avalanches release due to crack propagation in a weak snow layer under a cohesive snow slab. Crack propagation speeds can provide insights into the potential size of avalanches and inform fracture and avalanche release models. Despite their i ...

CAMBRIDGE UNIV PRESS2023

Transition from sub-Rayleigh anticrack to supershear crack propagation in snow avalanches

Johan Alexandre Philippe Gaume, Bertil Trottet, Grégoire Bobillier, Alec van Herwijnen

Avalanches can occur when a porous snow layer lies beneath a dense cohesive snow slab. Field experiments and simulations now reveal different crack-propagation regimes in slab avalanches, similar to rupture propagation following an earthquake. Snow slab av ...

NATURE PORTFOLIO2022

Crack propagation speeds in weak snowpack layers

Johan Alexandre Philippe Gaume, Jürg Schweizer, Bertil Trottet, Grégoire Bobillier, Alec van Herwijnen

For the release of a slab avalanche, crack propagation within a weak snowpack layer below a cohesive snow slab is required. As crack speed measurements can give insight into underlying processes, we analysed three crack propagation events that occurred in ...

CAMBRIDGE UNIV PRESS2021

Micro-mechanical insights into the dynamics of crack propagation in snow fracture experiments

Johan Alexandre Philippe Gaume, Jürg Schweizer, Grégoire Bobillier, Alec van Herwijnen

Dry-snow slab avalanches result from crack propagation in a highly porous weak layer buried within a stratified and metastable snowpack. While our understanding of slab avalanche mechanisms improved with recent experimental and numerical advances, fundamen ...

NATURE RESEARCH2021

Micromechanical modeling of snow failure

Johan Alexandre Philippe Gaume, Jürg Schweizer, Grégoire Bobillier, Alec van Herwijnen

Dry-snow slab avalanches start with the formation of a local failure in a highly porous weak layer underlying a cohesive snow slab. If followed by rapid crack propagation within the weak layer and finally a tensile fracture through the slab, a slab avalanc ...

2020

Snow slab avalanches start with a failure in a weak snow layer buried below a cohesive snow slab. After failure, the very porous character of the weak layer leads to its volumetric collapse and thus closing of crack faces due to the weight of the overlayin ...

ELSEVIER2019

Snowslab avalanches start with the failure of a weak snow layer buried below a cohesive snow slab. After failure,the very porous character of the weak layer leads toits volumetric collapse and thus closing of crack facesdue to the weight of the overlaying ...

2019

Snow fracture in relation to slab avalanche release: critical state for the onset of crack propagation

Johan Alexandre Philippe Gaume, Nander Wever, Jürg Schweizer, Alec van Herwijnen

The failure of a weak snow layer buried below cohesive slab layers is a necessary, but insufficient, condition for the release of a dry-snow slab avalanche. The size of the crack in the weak layer must also exceed a critical length to propagate across a sl ...

Copernicus GmbH2017

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The process of dry-snow slab avalanche formation can be divided into two phases: failure initiation and crack propagation. Several approaches tried to quantify slab avalanche release probability in terms of failure initiation based on shear stress and stre ...

2016

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If a weak snow layer below a cohesive slab is present in the snow cover, unstable snow conditions can prevail for days or even weeks. We monitored the temporal evolution of a weak layer of faceted crystals as well as the overlaying slab layers at the locat ...

2016

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