English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

. Dynamic crack propagation in snow is of key importancefor avalanche release. Nevertheless, it has received very littleexperimental attention. With the introduction of the propagation saw test(PST) in the mid-2000s, a number of studies have used particle trackinganalysis of high-speed video recordings of PST experiments to study crackpropagation processes in snow. However, due to methodological limitations,these studies have provided limited insight into dynamical processes such as theevolution of crack speed within a PST or the touchdown distance, i.e. thelength from the crack tip to the trailing point where the slab comes to reston the crushed weak layer. To study such dynamical effects, we recorded PSTexperiments using a portable high-speed camera with a horizontal resolutionof 1280 pixels at rates of up to 20 000 frames s−1. We then used digitalimage correlation (DIC) to derive high-resolution displacement and strainfields in the slab, weak layer and substrate. The high frame rates enabledus to calculate time derivatives to obtain velocity and acceleration fields.We demonstrate the versatility and accuracy of the DIC method by showingmeasurements from three PST experiments, resulting in slab fracture, crackarrest and full propagation. We also present a methodology to determinerelevant characteristics of crack propagation, namely the crack speed(20–30 m s−1), its temporal evolution along the column and touchdowndistance (2.7 m) within a PST, and the specific fracture energy of the weaklayer (0.3–1.7 J m−2). To estimate the effective elastic modulus ofthe slab and weak layer as well as the weak layer specific fracture energy,we used a recently proposed mechanical model. A comparison to already-established methods showed good agreement. Furthermore, our methodologyprovides insight into the three different propagation results found with thePST and reveals intricate dynamics that are otherwise not accessible.

Dynamic crack propagation in weak snowpack layers: insights from high-resolution, high-speed photography