About 100 people attended the Canadian Avalanche Association’s Backcountry Workshop at the Revelstoke Performing Arts Centre on Friday. The workshop featured a host of avalanche experts from around Western Canada who addressed a variety of topics such as how transceivers function to making proper terrain choices.
The talks were a mix of basic information and more technical knowledge. Here are brief summaries of some of them. Each presentation will be put on the CAA’s website at www.avalanche.ca in the future.
Understanding the new avalanche bulletins
Grant Statham, a mountain risk specialist with Parks Canada, was the first speaker. He talked about the development of the avalanche bulletins that were introduced last year and adopted by Parks Canada and the Canadian Avalanche Centre.
He talked about the criticism the bulletins received – namely the switch to a more graphical format instead of a text-heavy bulletin.
The goal of the new system was to make it faster to go through and easier to understand, however many experienced users complained about the absence of the more technical information. Revelstoke backcountry users were especially vocal in their complaints, Statham said.
“There’s substantial information in this bulletin, you just have to know how to pull it out,” he said.
He focused on the meat of the bulletin where the ‘key problems are listed, and how to interpret the graphics to answer four key questions – what is the problem? Where is the problem? How easy is it to trigger? How big can the avalanche be?
All four of those questions could be answered by looking at the graphics, but it would be up to the reader to decide how to use that information when making terrain choices that day.
“Simplicity is the ultimate specification,” he concluded.
At the end of his talk, Statham did say that Parks Canada would be including a second page to its bulletins that would include more detailed information for experienced users. This is something that was part of the CAC bulletins but not implemented by Parks. He also said weather information would be improved upon.
James Floyer, PhD, a forecaster with the Canadian Avalanche Centre, went over avalanche characteristics.
“If you understand the nature of the problem, you can deal with it more easily,” Floyer said.
He looked at eight different types of avalanches:
1. Storm slabs: They occur following snow storms. They are generally powdery and release below the trigger. To mitigate exposure, stay out of steep terrain, gullies and other terrain traps.
2. Wind slabs: A cohesive slab formed by wind-transported snow. They form on lee slopes and can be identified by looking for little ridges or furrows on the snow. The snow generally feels stiffer and cracking can be seen underfoot. They can be avoided by staying off wind-loaded slopes.
3. Persistent slabs: Result from a weak layer forming in the snow pack, they can last for several weaks and are hard to predict when they will trigger. Listen out for whumpfs (the sound the snowpack makes when a weak layer collapses) and stick to conservative terrain such as thicker trees.
4. Deep persistent slabs: Like persistent slabs, they are the result of a weak layer and can persist for much of the winter. While harder to trigger, they result in massive avalanches. Warming weather leads to a greater chance of one being triggered, so avoid avalanche terrain during periods of rapid warming.
5. Wet slabs: They require the saturation of snow with water and are more common in the spring and when there’s no overnight freeze.
6. Loose, dry: Generally the result of sluffing of surface snow, loose dry avalanches are generally smaller and easily manageable, as long as the sluff doesn’t take you off your skis.
7. Loose, wet: These are slower moving than their dry counterparts and are easy to avoid, as long as you don’t fall in its path.
8. Cornice releases: Happen when cornices collapse onto slopes, causing all sorts of havoc.
Transceivers, and issues with signal overlap
Rob Whelan’s talk on avalanche transceivers was one of the most interesting of the day. Whelan is a guide with Canadian Mountain Holidays and he’s responsible for their transceivers. He went over he factors he looked at when making a purchase, but the most informative part of his talk was his explanation of signal overlap between various beacons.
“There’s definitely still some mystery around these things,” he said.
One of his first points was that pretty much all transceivers work well in a single-burial situation. It’s when there are multiple burials that the workings of different transceivers comes into play.
Whelan said the processors in transceivers can sort out different signals based on the time between beeps, as well as the length of the beep (to dumb it down a little). A major problems comes when signals overlap, at which point many transceivers can’t differentiate between signals. The overlap can range from a few seconds to more than a minute, depending on what transceivers are present. This means that for some time your transceiver might only pick up one signal when there are multiple burials.
He said older transceivers have longer signal overlap and, while modern ones still have overlap, the signals migrate apart much quicker. He signalled out the Ortovox F1 as being particularly problematic.
A member of the audience asked about the impact of cell phones. Whelan replied that phones should be kept at least 40 centimetres away from your transceiver. “Where you’ll really see cell phone interference is in the search,” he added.
Two of the presentations were about experience backcountry users who made near-fatal mistakes.
Do avalanche airbags work?
James Floyer returned to the stage to present research done in avalanche airbags by his colleague, Pasal Haegeli.
The packs work due to a process called inverse segregation, which essentially causes bigger objects to rise above smaller ones.
The key question, though, is do they work? The answer was a definite ‘yes’ but with some caveats. Based on the research, airbags increase survival rate by 10 per cent. What that means is that if 100 people get caught in an avalanche with an airbag and 100 get caught without one, the first group will have 10 more survivors. Those numbers include instances where the airbag didn’t deploy; when an airbag does deploy, your survival chance is 15 per cent greater.
“The bottom line is airbags are effective and they do save lives,” Floyer said.
Interestingly, the rate of non-deployment in Canada is higher than the rest of the world, which Floyer said could be because there’s more snowmobilers here and its harder to pull the cord when you’re riding your sled.
Floyer also discussed the question of whether airbags lead to an increase in trauma. “The data doesn’t support using airbag packes increases trauma,” he said.
At the same time, he did mention some risks with airbags, notably that getting swept into terrain traps like a gully or stand of trees could still lead to burial because if you stop moving, the snow will just pile on top of you.
Search and Rescue
Tom Riley, a manager with Revelstoke Search and Rescue, talked about the organization and what to do if you get stuck in the backcountry and need a rescue.
“We are not the fun police,” he said. “I like to think of ourselves as alpine janitors.”
One of his key points was that planning and communication could reduce the need for a rescue. Make sure you know where you’re going, how to get out, and regroup frequently to make sure everyone’s there.
If you do get stuck, lost or injured, SPOT beacons, satellite phones and possibly even cell phones are handy. He stressed the need to conserve battery power on your phone so SAR can keep in touch.
If you see a rescuer, move around so they can tell you apart from the surroundings. For sledders, if you hear other snowmobilers, turn on your headlights so they can see you. If you see a helicopter, it might just be there to survey the situation. Hold tight, because it will likely come back. And if they drop an overnight pack, it means you’re sleeping outside.
Riley also went over problems with out-of-bound skiers at Revelstoke Mountain Resort. His key points there:
– Don’t ski below the Ripper Chair; it’s full of icy waterfalls, cliffs and unskiable terrain. “There is no fun to be found here,” he said.
– If you head out into the cat-ski terrain south of boundary, don’t go below the final cat road because you’ll soon find yourself in narrow gullies and creek beds that funnel you away from the resort.
He also warned inexperienced skiers of following tracks, because if you don’t know where they go, you can quickly find yourself stuck.
Uwe Gramann, the lead meteorologist for the CAC, gave a very informative and entertaining talk about how to factor weather reports into your planning. Perhaps his biggest point was to look for text forecasts rather than graphic ones because they provide more information.
“Friends don’t let friends use weather icons,” he said. “If you’re preparing, skip the symbols. If your website only gives you symbols, skip the website.”
Perhaps most valuable infor in his talk was a list of weather resources to consult, ranging from Environment Canada weather bulletins to far more complex NAV Canada forecasts.
Two books he recommended were Mountain Weather by Jeff Renner and Weather of BC by Robin Pigott. He also suggested consulting the Weather of BC Graphic Area Forecast available free online through NAV Canada.
For online resources, he suggested the University of Washington Department of Atmospheric Sciences, NAV Canada, Environment Canada’s FPCN68 highway forecasts for mountain passes, NAV Canada, Cliff Mass’ weather blog, and Jetstream, the U.S.’s National Weather Service’s Online School for Weather.