New research from the SLF in Davos, Switzerland, shows that cracks in weak layers can propagate at over 100 m/s, which is much faster than previously thought possible.
“Previously, it was assumed that such cracks propagate at speeds of between 20 and 80 metres per second. SLF researchers wanted to learn more. They have now experimentally demonstrated that cracks propagate faster than expected, even exceeding the previously assumed theoretical boundaries for this process in snow,” states the SLF in an article on LinkedIn.
The experiments were carried out by Bastien Bergfeld on a site near Davos, which is where the WSL Institute for Snow and Avalanche Research (SLF) is based. To carry out the test, Bergfeld found an experimental test slope, then preserved it until the time was right to trigger an avalanche. Using high-speed cameras, he was able to record crack propagation speeds of up to 130 m/s.
The experiment confirms findings from computer models, but Bergfeld acknowledges they took place in controlled conditions. “We don’t yet know how often this rapid crack propagation occurs in the natural environment and what role the properties of the snowpack play in this process,” he says.
