With the prospect of getting to witness large explosions, I made my way out to the Mile 45 Warden’s station on the Icefields Parkway with a feeling of giddy excitement, preparing for a day of avalanche control operations with Parks Canada’s Public Safety crew.

Arriving at the Warden’s station, I soon realized that avalanche control encompasses far more than dropping bombs, skiing deep powder and enjoying the fact that the day’s highlight doesn’t include some colleague regaling you with stories about a youtube video they found the previous evening of a guy playing Stairway to Heaven, note for note, on his ukulele.  

Welcoming me at the door of the Warden’s Station was Rupert Wedgwood, crew member and my tour guide for the day. As the morning briefing with crew members concluded, I became attuned to the reality that avalanche control operations are more Top Gun than Warren Miller or Ski School (part one or the lousy part two). Simply put, operations are coordinated and executed with military-like precision and ability.  

With the crew briefed, we headed off to the Parker Ridge area along the Parkway, at which point Steve Blake, Jeanine D’Antonio, Geoff Skinner, Al McKeeman, A.L. Horton and J.P. Kors prepared the necessary equipment, including the explosives and their skis and set off on a 45 minute trek to an area along the ridge where detonation would take place.  

Science of the Snowpack:

As Blake, D’Antonio, Skinner, McKeeman, Horton and Kors made their way up to the detonation zone, Wedgwood explained what happens to snow that causes avalanches.  Gauging the stability of the snowpack requires an examination of the temperature, depth of snow, the position of the sun in the sky, slope angle, the direction a slope faces, elevation, and knowledge of weather systems that have crossed the area since the beginning of the season, said Wedgwood.  

This has been a relatively quiet year for avalanches in Jasper National Park and March 18 was the first time this season that the public safety crew has been out for control operations. “If you were to add up all the dribs and drabs we’ve had since November,” said Wedgwood, “we have a little over 300 cm of [snow]. Of course it all settles and condenses... this may result in a metre of snow condensed.”  

Wedgwood estimated Jasper National Park is probably down by at least 25 per cent in snowpack depth compared to a more typical year, creating what he termed, a “shallow snowpack.”  Combined with the cold temperatures experienced around Christmas, a shallow snowpack can prove dangerous for backcountry revelers and motorists on the highway.  “When you get fresh snow on top of a weak, unconsolidated snowpack,” he said, “you can get large releases.”

More scientifically speaking, the combination of cold temperatures with a shallow snowpack creates a “metamorphic effect,” said Wedgwood, which produces “sugar-like snow.” Sugar-like snow is characterized by large crystals, which are not cohesive and therefore unstable, he said.  When a layer of fresh snow piles on an unconsolidated snowpack, avalanches can happen.  

This time of year can also prove tricky for avalanche forecasters due to the position of the sun in the sky. “The sun’s a lot higher in the sky, the day length is longer, the air temperature is much warmer and on south-facing slopes, we end up with a lot more avalanche activity,” Wedgwood explained. The snowpack may be frozen in the morning,  appearing stable, but by the afternoon it begins to loosen up and avalanches can occur, he said.  

Typically, avalanches are found on slopes in the 20- to 45-degree range, but “most commonly it’s in the 30-degree slope angle that it’s a problem,” said Wedgwood. An attendant consideration is the complexity of the slope. “If the slope is steep and it has convex rolls in it, so steep areas which are unsupported... that can lend itself more towards avalanche terrain,” he said.  

The aspect of the slope, in other words the direction the a slope faces, is also very significant due to the impact of prevailing winds. Gusts pick up the snow, “smashing it into smaller pieces,” said Wedgwood, with north and east facing slopes accumulating more snow, making snowpack depth harder to determine. Additionally, “slopes that are high up in the alpine are more exposed to the wind,” he said.  

Varying weather systems also produce different layers within the snowpack.  “As storms come and go or warm dry spells come and go, they all result in different interfaces and different layers and we’ll track different events... we’re still tracking a November rain crust that’s right near the bottom of the snowpack,” said Wedgwood. “So a combination of snowpack observations, weather observations, and then just our local knowledge of the terrain enables us to go out and tell when we have to do avalanche control,” he said.

What is Avalanche Control?

Basically, the reason the crews create avalanches, is to prevent them. “You close the highway, you have a trained team, you go up and you create avalanches to remove snow from start zones,” said Wedgwood. “If you were to get a 20 cm dump overnight, there isn’t enough snow below it because you’ve been doing your control work, to create an avalanche that could hit the highway,” he said. 

In a typical season, crews would head out about four times conducting control work across the 40 avalanche paths that punctuate the highway area. Each of those 40 paths can also have numerous start zones, requiring cleaning out, said Wedgwood.  

Blake and the rest of the crew went to the top of the ridge to prepare explosives for deployment. The six crew members humped up the ridge four 12.5 kg bags of a diesel and fertilizer mix, multiple 8 oz TNT hand charges, detonation cord, fuse lengths, and explosive caps with pull-wire igniters. Barely able to make out the figures, except through my zoom lens, crew members assembled three explosive charges – in what can best be described as a series circuit arrangement – and lowered the charges down into the start zones.

“The avalanche path is divided up into three major zones,” said Wedgwood.  “The start zone, it’s where we deploy the explosives. The track is what the avalanche debris flows down and then the run-out or the fan is at the very bottom,” he said. The section of highway below Parker Ridge meanders through the track of the avalanche path, a higher risk area for the motoring public and that is why Blake and the crew began work in that particular local, added Wedgwood.

Risky operations, such as avalanche control, require a strong team effort, lots of preparation and a clear understanding of every crew member’s responsibility.  “Whether it’s a search and rescue operation, or an avalanche control operation, we employ what’s called the instant command system,” said Wedgwood, “which defines a chain of command and a scope of responsibility for each position.”

On this particular day, Steve Blake was the instant commander responsible for operations. Maintaining a chain of command reduces or mitigates the danger to not only the crew members at the top of the mountain, but all the support staff, such as the highway cleaning crews responsible for clearing avalanche debris, at the bottom. “That just makes sure that people aren’t taking on too much responsibility, that they have a good span of control,” said Wedgwood, adding that this reduces the possibility of distraction “and that way things don’t get overlooked or the chances of things getting overlooked is less.”  

With the explosives ready and the crew safely up and out of the avalanche path, Blake’s voice came through Wedgwood’s radio loud and clear, “fire in the whole.”  I waited patiently with my camera trained on the ridge – for what seemed like half an hour, but was really only about five minutes – ready to capture the explosion and resulting avalanche. The fuse burned away and finally the detonation occurred. The explosion and subsequent avalanche was both awe-inspiring and humbling in the same moment.  You don’t want to screw around with mother nature, I thought. 

With the perilous portion of the day complete, Blake, D’Antonio, Skinner, McKeeman, Horton and Kors all skied down the cleaned out slope to waiting vehicles.  Now for the fun part of the day, the Avalauncher.  

The Avalauncher is essentially a cannon, propelling explosive charges into start zones that can’t otherwise be easily or safely reached by crews for control operations. A sort of potato gun on steroids probably best describes this piece of artillery, but instead of lighting hairspray to launch a starch ordnance into low orbit, the Avalauncher uses nitrogen and launches TNT in sort of a Nerf football-shaped charge.  

Aiming is done by line-of-sight, said Wedgwood, and Avalauncher operators must be cognizant of wind conditions when preparing to fire. The area that crews were launching at is nicknamed ‘Parker Slabs’, where one massive slab of granite overlaps another.  Wedgwood referred to the overlaps as the “bookends,” with the space between the bookends as sort of the bulls-eye for the Avalauncher.  

Judging how much of an explosive charge is sufficient to create an avalanche comes with experience and an apprenticeship, said Wedgwood, and depends on the situation. Even though the level of charge is associated with the success of the operation, a loud bang and lots of smoke doesn’t constitute a success.  According to Wedgwood, “what we’re trying to do is clean out as much snow as possible. Our success is based on clean out” and not on how big or small of an avalanche we create. The March 18 operation was indeed a success with about a 70 per cent clean out, Wedgwood estimated.  

Public Safety and Responsibility

“The national parks are really here for people to explore, enjoy and experience, so we really try to give people as much information as they need to go and do the activity as safely as they can,” said Wedgwood, “but we stress self-reliance and part of self-reliance is being educated.” 

The control crews embody the edict of self-reliance as well. “One of the ways we manage that sort of residual danger from day-to-day is just making sure we’re really good with our self-rescue and we try and make our decisions with a very solid buffer of ‘what if?’, Wedgwood emphasized, adding that “we are continuously hedging on the side of safety.”  

There is plenty of information available on both the Parks Canada (www.pc.gc.ca) and Canadian Avalanche Association (www.avalanche.ca) websites that is updated daily by  six avalanche forecasters in the park. Conditions listed on these websites pertain to both the highway and the backcountry. “On days when the avalanche danger is very high, it’s a no-brainer. Don’t go out unless you’re very experienced and know the locations where you can go where there is no avalanche danger,” said Wedgwood.  “When the avalanche danger is very low, it’s also a bit of a no-brainer, you can go most places,” he added.  

The most basic advice for the motoring public is not to stop between signs that indicate avalanche danger. For the backcountry, “people should carry the [safety] equipment... which are transceivers, shovels and probes,” said Wedgwood, adding people “should know how to use them.”

Even experts like Wedgwood, Blake, D’Antonio, Skinner, McKeeman, Horton and Kors are not invincible. “Anybody’s that’s been involved in the avalanche industry for a lifetime has probably been caught in avalanches,” said Wedgwood, “and that really just makes you pretty humble and honest... accidents can happen.” For the crew, “there’s lots of history and memories” in the Parker Ridge area, due to the deaths of friends.  

The crew members put themselves in harms way, albeit in a relatively controlled manner, so that the motoring public can safely venture from Banff to Jasper throughout the winter months.  “I think sometimes members of the traveling public, they see us out on skis and they think, ‘Okay, government workers just out having fun’,” said Wedgwood, “but every day during the winter it’s our responsibility to make sure the highway’s safe and one of the ways we do that is by going out and collecting snowpack information.”

Why They Do It?

Arriving in Canada about 20 years ago with little more than a backpack and climbing rope, Wedgwood got into his specialized public safety position through his interest in ski mountaineering and touring. “For me, mountaineering and being involved in those activities... it’s an opportunity where you have to use many things that you don’t get to use that often on a regular office day,” he said. “You’re using judgment, you’re using your intuition, you’re using skills which have taken many many years to develop.”

Even though mountaineering is a “pretty self-absorbed, almost narcissistic activity,” Wedgwood joked, it’s crucial that as a crew they function well as a team at all times during the operation. “Some of these people I’ve climbed and trained with for close to 20 years and so there’s a great team spirit amongst those of us that do this and it’s really quite something when you go out to try and pull something off that’s tricky and technical and you come away saving somebody’s life,” Wedgwood said.  

Functioning with a team mentality is also something considered when incorporating new people into the crew for succession planning. “Sure they might have great technical skills, they might be good decision-makers, but can they function well in a team setting?” said Wedgwood, adding that “like any workforce these days, with the greying workforce, we have to plan for the next generation so we’re trying to take out younger people and expose them to this profession so we can pass on the knowledge because in ten years, most of us will be gone.”  

Like with any military operation, there is a debriefing for the avalanche control crew, where they discuss what went well and what could be improved upon in the future. You have to be “able to sit back and be very objective and self-critical,” said Wedgwood. “Every operation is an opportunity to get better.”