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Assessing danger

Avalanche Days come at a crucial time



Whither Ullr? The Norse snow god, usually depicted on skis with a bow and arrow, has not only left the resort, but, it appears, the entire province.

Revered for sprinkling white fluff across winter wonderlands the world over, Ullr is also something of a protector, the god with the shield. And yet, this winter has seen a staggering number of backcountry avalanche deaths — 13 in less than a month.

Figures like that make the annual Avalanche Awareness Days (AAD) rather topical. Though AAD’s main hoorah went down in Revelstoke last weekend, related events played out in snow spots across Western Canada, from Banff to Squamish. B.C. Parks Ranger Aaron Donohue, with colleagues Simon Gravel and Mark Latham, were the local point guards for the event, and they set up a demonstration at Red Heather Lodge, a little over five kilometres up Garibaldi Provincial Park.

And it was snowy up there. The trees were heavy with it, almost lazy with it, slumping across the trail here and there. And the temperature was mild, a fact Donohue deposited in the back of his mind. If you see balls of snow tumble from trees or roll down chutes, you make a note of it. It’s a sign of warming temperatures, nothing to ring the alarm over, not right away, but something to remember. Warming trends, after all, cause the snowpack to weaken.

And you need to understand the snowpack if you’re going to venture into the backcountry. That’s why Donohue dug out a two-metre cross section behind the lodge.

“Picking where you dig the snow pit is a big part of evaluating the snowpack,” he said, a small assembly of snowshoers, skiers and other backcountry enthusiasts gathered round.

For example, a bad spot would be directly under a tree, where falling snow has impacted the pack.

Donohue’s snowpack acts as a record of the season’s snowfalls. You can see a rain crust from early January’s deluge, and, beneath that, you can see December’s bountiful offerings compressed by the weight of what’s above. That rain crust could pose a problem. So could the ice crust a ways beneath it.

“That provides a good surface for snow to slide on,” he said. “(But) this pit isn’t representative of stuff out there. Ever.”

He’s talking about anywhere else. Variability is a major factor when trying to gauge the likelihood of an avalanche. Even on the same slope, even just a short distance away, there can be a lot of variability in the snowpack.

Often, your eyes aren’t enough. Sure, you can see the different layers — but how cold are they? The ground temperature is usually around zero degrees Celsius, even if the surface is minus-40. The surface was above zero that day, and mid temperature was minus-10 — though it will start to equalize as the winter wears on.