Trees that stick up through the snowpack can help to hold the snowpack in place, slowing or stopping an avalanche. A thick, mature grove of evergreen trees can anchor a slab effectively!
Trees protect communities along the Wasatch against landslides and avalanches. Forests are an affordable and ecologically friendly means of protection. Both standing and fallen trees stabilize the snowpack and prevent avalanches and can reduce the size of the snow slab that is released. In the forest, snow falls from the trees, and the canopy supports the energy balance of changing snow layers. Because the forest snowpack is subject to often unseen inconsistencies weak layers can form and can avalanche naturally or when disturbed. So a healthy and thriving surrounding forest is able to stem and buffer some avalanches. If the trees can withstand the tremendous rushing force of an avalanche, it loses energy and its progress towards the valley below.
More research and information is being gathered around the world, numerous forest avalanches have been examined, documented, and even simulated to find answers and solutions to mitigating avalanche damage. Tree anchors need to be thick enough to be effective. The more thickly spaced, the more effective. Sparse anchors, especially combined with a soft slab, have very little effect. Spruce and fir trees with branches frozen into the slab are a much more effective anchor than a tree with few low branches such as an aspen or lodgepole pine. Also, snow falling off of trees tends to stabilize the snowpack around trees.
And recently a skier caught in an avalanche that killed four people in Utah survived by clinging to a tree through the onslaught of rushing snow and later helped save two people. Winters have been especially deadly in the U.S., with avalanches coming amid increasing interest in backcountry runs as skiers try to avoid crowded resorts during the pandemic. In the US, avalanches kill 25-30 people and injure many more each winter. Some days are dangerous and some days are not … learning about avalanches will help you decide when, where, and how to visit the backcountry. Learn more about safety at: https://avalanche.org/avalanche-education/ or at https://utahavalanchecenter.org/
