Drawing on the fact that the snow in an avalanche can behave like both a solid and a fluid, a researcher has managed to simulate a snow slab avalanche with unrivaled precision, with the help of researchers used by The Walt Disney Company for the movie Frozen. The model detailing the process of avalanches will further help to identify potentially hazardous mountain areas as well as help to protect tourists and locals from the unpredictable natural phenomenon.
An avalanche is an extremely complex event, with countless parameters and physical variables coming into play from the time the avalanche is triggered until it ends and until recently, scientists could not pre-determine the site of the avalanche, or calculate the direction and speed of its movement. However, thanks to the joint work of geofizikov, mathematicians, and engineers of The Walt Disney Company, they have been able to design a computer model of the natural disaster and are now able to make reliable predictions.
Johan Gaume, a researcher in the Laboratory of Cryospheric Sciences (CRYOS) and SLF, has created a highly accurate digital simulation of an avalanche which could be used to improve risk management in the mountains. The avalanche expert spent several months last year at the University of California Los Angeles (UCLA) working with 3D modeling experts, some of whom had worked with Disney’s engineers to simulate the snow in the film Frozen. Combining these mathematicians’ know-how with Gaume’s scientific expertise turned out to be a winning formula.
Adopting a whole new approach, the Swiss and US researchers created the first realistic, complete and scientifically rigorous simulation of a snow slab avalanche, a type of avalanche that occurs when a very clear linear crack appears at the top of the snowpack. This usually happens when, over a large area, there is a weak, and therefore not very cohesive, snowpack layer under the dense top layer of snow, known as the slab. Snow slab avalanches are hard to predict and often triggered by skiers or walkers, making them the most dangerous and the most deadly type of avalanche.
“What made our approach so original was that we took account of the fact that the snow in that type of avalanche behaves like both a solid and a fluid,” explains Gaume.
The researchers were able to simulate the collapse of the porous bottom layer for the first time at a large scale using a continuum approach. In addition, the model integrates only the relatively few key parameters that dictate how the snow will behave at the various stages of the process; these include the dynamics of the fracture, friction, and the level of compaction based on the type of snow.
“In addition to deepening our knowledge of how snow behaves, this project could make it possible to assess the potential size of an avalanche, the runout distance and the pressure on any obstacles in the avalanche’s path more accurately,” says Gaume.
The researcher’s simulations could also be applied in the arts, and especially in future animated films.