Forecasting a snow avalanche takes more than measuring the angle of a mountain slope, researchers report in the July 11 Science. Whether an avalanche happens might also depend on how the snow cracks and collapses, the study suggests.
“The new theory could be a breakthrough in understanding what is going on at the very moment when an avalanche begins,” says University of Edinburgh physicist Joachim Heierli, lead author of the study. It “gives hints on what snow properties to look for to anticipate the risk of triggering a slab avalanche.”
Slab avalanches are the most common and most dangerous because a slab of snow breaks loose and cascades to the slope’s bottom. By modeling this avalanche type the team found that snow fractures much more easily than previously thought. Also, friction between snow layers may be more important in avalanche dynamics than once thought.