Avalanche in Sheol Valley
Posted: March 31, 2009 Filed under: Winter 2011-12 | Tags: avalanche, Lake Louise, Sheol Valley 5 Comments »It’s been two weeks now since an avalanche buried two people in Sheol Valley south of Lake Louise. A party of four went for a ski tour, making their way to Surprise Pass. Crossing a large gully feature on the south face of Mt. Fairview, an avalanche started at the top of the slope and carried two of the party over one thousand vertical feet to the bottom of Sheol Valley, which separates Sheol Mt. from Mt. Fairview and Saddle Mt, and drains into Paradise Valley. This incident made news right away in a season that has seen avalanches on the front pages of many newspapers, but it hit especially close to home once we realised that the two who were caught in the slide were a Lake Louise ski patroller and the wife of another.
The party of four, all of whom are experienced backcountry skiers and have years of ski patrolling and guiding under their belts, drove up towards the Fairmont Chateau Lake Louise and parked in the public lots close to the lake. The route to Surprise pass starts by following the summer hiking trail to Saddleback Pass, then continues around to the south side of Mt. Fairview into Sheol Valley and up to Surprise Pass, which lies between Mts. Aberdeen and Fairview and leads down to the Plain of Six Glaciers hiking trail. The route starts in the forest, emerging just below the final approach up to Saddleback Pass. From there, the route follows tree-line and makes its way around to the south-facing side of Mt. Fairview, which is where the first avalanche slope of the route is located.
The slope is a long gully feature that starts near Fairview’s peak and runs all the way to the bottom of Sheol Valley. It is typically a cross-loaded feature, meaning it gets filled by wind-transported snow from the side rather than from over the top. This means the skier’s right side of the gully has more snow than the left, at least in the part that receives the wind-blown snow.
The group had done some test snow profiles and had been discussing the stability of the snowpack the whole way up, and when they reached the gully feature, they judged it suitable to cross and decided to do so one by one. Skier 1 crossed the slope with no trouble. Skier 2 crossed as well, and was waiting behind the first skier for the other two to cross. As Skier 3 began to cross the slope, a fracture line appeared along the skier’s right flank of the slope and zipped with lightning speed almost to the top, where the snow began to slide. All of a sudden the entire slope was in motion, and Skiers 2 & 3 were hit by the snow already sliding quickly down from above. The two skiers were carried over a kilometre through small trees and open slope, ending up far apart from each other once the sliding snow hit the valley bottom and spread into a fan.
Skier 2 heard the fracture as it started, and barely had time to react before the snow began to move. She recalls trying to self-arrest, but was unsuccessful. Her only other memory was of trying to clear a space in front of her mouth with her hands as the debris came to a stop . She ended up at the bottom of the slope, face down and completely buried by snow.
Skier 3 was also carried the entire length of the slope, but on the skier’s left side. When the debris stopped moving, she was face up and partially buried. Her head, arms, and legs were out of the snow, and she was able to dig herself out and begin the search for her companion as the two skiers who weren’t caught in the avalanche joined her. With their avalanche beacons, they located Skier 2 and started to dig her out. They reached her head, and when they pulled her head out of the snow, she had been buried for around fifteen minutes, which is widely considered the maximum amount of time a person can go without oxygen before suffering irreversible brain damage. She was unconscious and not breathing, and her hands and face were blue from lack of oxygen. As soon as they uncovered her head, though, she began to breathe on her own, though she didn’t regain consciousness right away.
Once Skier 2 was uncovered and awake, Skier 3 complained of a sore neck. Another party member, her husband, also noticed her bleeding from an injury on her face and from an avulsion on the top of her head. The others immediately used extra clothing to fashion a cervical collar to stabilize her neck, and got her to lie down on a pair of skis to keep her rigid and unmoving. With the party out of immediate danger, the husband made his way back to the Fairmont hotel to call for help.
Shortly after, a helicopter with rescue crew was dispatched to the scene, and two ambulances made their way to the parking lots by the lake to use as a staging area. All party members were flown out, with the two buried parties being taken to the hospital in Banff. Skier 3, with the neck injury, was transported by STARS air ambulance to Foothills hospital in Calgary. It was later confirmed that she had six fractured vertebrae – three in her neck. The doctors there expressed amazement that she was not paralyzed given her injuries.
Skier 2 spent a short time in the Banff hospital, then returned to her home in Lake Louise. She had suffered severe frostbite to her hands, since when the body is deprived of oxygen, the extremities are the first places to stop getting circulation, and her hands froze up right away, later requiring lacerations to relieve pressure from the swelling. Her hands are almost back to normal, and after four or five days of fatigue and soreness, she has returned to work on the patrol. She heads back to her real home in New Zealand in a few days for some much needed relaxation.
Skier 3 spent some time in hospital in Calgary, and has been home now for about a week. She is wearing a halo for the next two or three months to keep her head and neck still while the fractures have a chance to heal. While her recovery will be slower, she will recover, and is expected to return to 100%. She has a few staples in her scalp to treat the avulsion, and had a loose tooth repaired as well.
For the two skiers not caught in the slide, they both knew right away as it happened that this was serious. As soon as the debris came to a stop, they checked above to ensure there was no further possibility of avalanches on that slope, then skied down the slide path to begin the search for the other two. Skier 4, the husband of Skier 3, didn’t allow the fact that his wife was in serious danger to distract him from performing the search safely and according to his training.
We’re all relieved beyond words that our friends and coworkers emerged alive from an event that otherwise could have had a very different outcome. And, while the physical wounds will heal, I can’t imagine this event will be one any of the four will ever forget.
The Google Earth diagram linked to below shows the approximate route to Surprise Pass from the parking area near the Chateau Lake Louise, as well as the avalanche path as it ran that day and the locations of the skiers. All are approximate. The photos below the diagram were taken by Parks Canada wardens from the helicopter that perfomed the rescue.
Click link for diagram —> sheol-valley1
Avalanche start zone, 200m above skiers (photo: Parks Canada)
Top of the avalanche path, looking down into Sheol Valley. Skiers were just above treeline (photo: Parks Canada)
Getting ready to fly (photo: Parks Canada)
Longlining (photo: Parks Canada)
Ambulances wait near the Fairmont Chateau Lake Louise (photo: Parks Canada)
Avalanche in West Bowl
Posted: January 10, 2009 Filed under: Winter 2011-12 | Tags: avalanche, Lake Louise, west bowl 6 Comments »Despite all the recent news of avalanche fatalities in North America and despite no shortage of warnings of high to extreme avalanche hazard in the backcountry of Banff National Park, two riders found the lure of untracked powder too powerful to resist today just outside the area boundary of the Lake Louise Ski Area.
West Bowl is located immediately west and outside of the Outer Limits boundary fence, and is probably the most travelled area outside the boundary due to ease of access. It can be reached from the top of Outer Limits or through the Window, which accesses the very top of the bowl as you head towards Boomerang.
Below is a diagram that’s posted at the Outer Limits access point to West Bowl:
Parks Canada diagram of West Bowl - © Parks Canada
About mid-afternoon today (which, by the way, was Avalanche Awareness Day at Lake Louise), a patroller working in the Summit area was skiing down Outer Limits, and stopped to look into West Bowl. She saw a startling sight – West Bowl had avalanched, and there was a boarder above the slide climbing back to the top of the ridge, and another in the debris pile trying to dig himself out. The avalanche was reported to our Avalanche Forecaster, who immediately instructed patrol dispatch to contact the Parks Canada warden service to prepare for and assist with a possible rescue, then started to head that way with other members of the avalanche control team.
As I mentioned in a recent post, Lake Louise Ski Patrol will respond to an out-of-bounds rescue, but the avalanche forecaster is the only person who can authorize any staff member to leave the area boundary, and except in very low-hazard conditions, only those patrollers with their Canadian Avalanche Association Level 2 avalanche course certification will be involved in the rescue. The public safety wardens called for a helicopter to assist in the rescue, but once it was confirmed that the two people we observed were the only ones involved in the avalanche and no rescue was required, it was called off. The wardens also stood down and let us do our thing.
A staff member was sent to the Window to intercept the person climbing back to ridge-top, and after ensuring their own safety, two patrollers skied in towards the rider who had by now dug himself out of the debris and was waiting for assistance. It’s possible to ski West Bowl most of the way down and still get back to the bottom of the Summit lift, but the avalanche had carried this one person well below that point, so he and the patrollers skied down the one prominent gully below called Deep Throat and down to the Monkey Trail (aka Star Wars), which is the long forest traverse that returns people to the resort via Juniper Jungle. Once in the avalanche forecaster’s office, they were able to tell their story…
The two were both snowboarders from Calgary in their 20′s, and, deciding to take advantage of the untouched powder, entered West Bowl through the Window. Even in good snow years, you need to pick your way through a few rocks to get down to the actual bowl since the top ridge gets scoured clean by the wind. Once they did so, the first rider decided to do a quick traverse across the top of the slope, but as he did so, he hit a rock that forced him to turn down into the slope. He then decided that since he was on the slope he might as well keep riding. He only managed a few turns when he realised the slope was starting to slide around him. As this realisation sunk in, and before he had a chance to react, the slide suddenly increased in width so that it covered almost two-thirds the width of the bowl – about 250m.
The avalanche slid to ground, and while the snow depth was only about 40cm or so, the depth and width combined to make a large avalanche – a size 2.5, which is enough to bury or kill a person, and typically has a mass of 100 tonnes. The rider was swept up and carried down the slope, and he described being tossed around, alternatively ending up on top of the debris and being completely buried, over and over again. He “fought like crazy” and tried to swim to stay on top, but the avalanche was just too powerful. When it came to a rest about 250m below where it started, the rider was upright and buried up to his chest. He looked up slope to see that his friend had not been caught in the slide, and noticing that there was still snow that had not avalanched, yelled for him to climb back up to the top rather than try to get to him and possibly start another avalanche. He had managed to free himself from the debris by the time patrollers arrived.
As he recounted his story, an hour or more had passed since the incident, and as the adrenaline faded, he broke into tears realizing how lucky he was to be alive. Had he been completely buried, the lack of oxygen would mean he only had about fifteen minutes before brain damage was likely, and his chances of survival would have plummeted. It was lucky that a patroller observed what was going on just after it happened and was able to report it, but even then, getting to the victim in fifteen minutes or less would have been unrealistically optimistic.
Both of these riders had taken avalanche awareness courses in the past, but the message appears not to have sunk in (although there’s no doubt in my mind it has now). Also, as the victim and patrollers arrived at the start of the Monkey Trail, there was a group of eight snowboarders who had just come down Maintenance, another out-of-bounds run near but not quite as big as West Bowl. Not one of them had avalanche rescue gear, and one of them, upon seeing the rider with the patrollers, remarked “Riding alone? What an idiot”. If only he knew…
The two boarders were asked to come to the avalanche office to tell their stories, because there are always lessons to be learned from an incident like this for both those involved and others as well. No doubt they’ll tell their families and friends about this. They were not punished, since they did nothing wrong from a policy point of view. Our boundary is open, and these two crossed it in a way that contravened no laws or resort regulations. What they did contravene are the protocols for safe travel in avalanche terrain – among others, know the hazard, have and know how to use a beacon, shovel, and probe, tell people where you’re going, and have a plan.
The two left here today with a new attitude about avalanches, and we hope they’ll spread that experience to as many people as they can. Others haven’t been so lucky.
“Closed” vs. “Out-of-Bounds”
Posted: January 2, 2009 Filed under: Avalanche Control | Tags: avalanche, boundary, in bounds, Lake Louise, out of bounds 2 Comments »With avalanche fatalities making news on a number of fronts lately, it seems a good time to outline the policy at Lake Louise with regards to boundaries and closures, and what the differences are between the two. And while I suspect that most of those reading this blog have a good familiarity with these aspects of the resort, it’s still probably a good idea to provide a reminder.
Most relevant to our operation were the two fatalities in Whistler, one each in separate avalanches on Whistler and Blackcomb mountains. News reports stated that each person had entered an “out-of-bounds” area, but also that both areas, while normally open during good snow years, were closed due to poor conditions – namely, high avalanche hazard and a minimum of control work. In our neck of the woods, out-of-bounds and avalanche closures are two separate things, and people need to be aware of those differences.
One of the things that makes public education a challenge is that there is no single universal policy in the ski industry when it comes to dealing with these areas. In some places, those leaving the resort boundary are subject to criminal prosecution. Others allow you to leave the resort, but make it clear that those requiring assistance or rescue will be responsible for the total cost. Given that many serious injuries require the use of a helicopter, patients could find themselves faced with a bill in the thousands of dollars.
Because Lake Louise is located in Banff National Park, the situation here is somewhat unique in the industry. Since those skiing at the Lake have entered the national park with a park pass, that pass covers any sort of rescue that may be required. This includes hikers who injure themselves far from the trailhead, and climbers who get stuck high on the mountain. (Having said that, those who make a habit of getting into enough trouble to require rescue may find themselves faced with the bill. This should prevent people from just assuming that a helicopter will come and whisk them off the mountain at the first sign of trouble).
Officially, the resort boundary dictates who will perform a rescue – inside is ski patrol, outside is Parks Service. Unofficially, the ski patrol will assist with backcountry issues close to the boundary, and the parks service will assist inside the boundary if their help is requested. This results in a great working relationship between the resort and the public safety wardens.
Out-of-Bounds
At Lake Louise, out-of-bounds means just that – any area that lies outside our operational boundary, which is marked with orange rope and bamboo fencing, and is identified with orange signs stating “Ski Area Boundary – Not Patrolled”. Our entire boundary is open, meaning there is no restriction with regards to when or where someone can leave the resort area to enter the backcountry (as long as they don’t travel through an avalanche closure to do it). At the same time, anyone considering a backcountry trip needs to realise that there can be a whole new set of hazards and implications involved with their decision.
First and foremost is the fact that no avalanche control is performed outside the resort boundary (except in a few cases where out-of-bounds terrain has the potential to avalanche into in-bounds terrain). So, even though a piece of backcountry terrain has the same characteristics (slope angle, aspect, elevation, etc) as somethings in-bounds, it has not received any of the ongoing control work that makes terrain safe for skiing.
Related to avalanche control work is skier compaction. The more traffic a piece of terrain gets, the more the snowpack gets compacted and pounded into the mountain face, adding to stability. Within the boundary we have a very good idea of the amount of skier compaction that has occurred on any given run. This is not the case for terrain outside the boundary, meaning that the stabilising effects of skier traffic are mostly unknown.
Another thing to consider when traveling outside the boundary is that rescue can take much longer to perform. Within the resort, assistance is only minutes away. In the backcountry, the rescue effort can be much more involved, and rescuers must ensure their own safety when approaching the site, especially in avalanche terrain. A serious injury such as a broken femur can be life-threatening, and if it takes a few hours for the injury to get reported and the patrol to locate the site and perform a rescue, it could be hours the patient does not have.
Avalanche Area Closures
Within and separate from the resort boundary are areas identified as avalanche zones. These are areas, mostly in the alpine, that the avalanche forecaster has deemed to be unsafe for skiing. Like the boundary, these areas are marked with orange rope and bamboo fences, but have different signage. These signs are stop sign-shaped, and use mainly red and white markings with the text “Closed – Avalanche Danger”. Unlike the boundary, entry into these areas when closed is not negotiable nor open to interpretation. Not only could the terrain be unsafe, but the patrol may be performing avalanche control work with explosives.
Entry into avalanche closures can be dealt with in a few ways. Generally, we aim for an “education, not alienation” approach when talking with “poachers”. However, if a poacher appears to have a bad attitude or lack of appreciation for why the terrain is closed, or if they appear unwilling to learn from the experience, then pass removal is the usual outcome. Season or multi-day pass holders must successfully complete an avalanche quiz at the end of their suspension in order to have their pass returned.
CLOSED! (tracks belong to patrollers - or those studying for a quiz)
Poachers almost never have any understanding of avalanche hazard and how it relates to weather or snowpack development, nor do we expect them to. We expect that people trust our experience and decision to keep terrain closed due to hazard, and that they obey all posted signage. A good example of poor knowledge came from one poacher who claimed “Well, it was open last year and it was okay then!”.
Anyone who rides Paradise chair already knows the most heavily poached spot on the mountain – the ER 4/5 fenceline (the fact that poachers are visible to a chair full of people never seems to occur to some of them). The common excuse we hear is “I was just inside the fence, how dangerous could it have been?”. We then explain that:
- by placing tracks in a closed area, you send the message to others that the terrain is open to be skied (sucker tracks).
- you endanger the lives of those who may be skiing below in open terrain.
- you endanger the lives of those who would come to your rescue in the event you got into trouble.
- you may have been by the fence, but the next person will go in further to get their fresh lines, and so on until people are skiing right in the heart of an avalanche slope.
In the end, all we can hope is that people respect the closures in place within the resort boundary, and that those traveling outside the boundary be prepared. The Ski Patrol at Lake Louise is always available to answer your questions. If they can’t, they’ll point you in the right direction to find out all you need to know.
Oh yeah, and…Happy New Year!
Snowfall at Lake Louise
Posted: November 18, 2008 Filed under: Winter 2011-12 | Tags: avalanche, lake louise snowfall Leave a comment »What a difference a week makes!
We’re starting to see a few more smiles on the faces of our avalanche control team and trail crew as they wander around the upper mountain of Lake Louise, thanks to our recent snowfalls. With over 20cm received last weekend, and more over the last few days, white has replaced brown as the dominant colour in the alpine, and with more snow in the forecast, we’re becoming optimistic that further terrain openings are not far off.
While the pervasive warm temperatures of late have put a damper on our snowmaking efforts, they have done a great job of settling our upper mountain snowpack, and so far this is a year where the snowpack is building right-side-up, but I’ll get to that in a moment.
Up to now, our avalanche control efforts have produced a number of results, with many avalanches sliding on a hard crust that formed during a rain event on November 2nd. This crust was hard enough to support the weight of a jumping skier, and provided a good sliding surface for whatever snow lay on top. Now, the warmer temperatures have resulted in a few things. Due to heat from the ground and the air, the crust has become moist, and is breaking down to the point that it will no longer support the weight of a skier. It is also becoming less of a distinct layer as it joins those layers above and below it. Only in places where there has been significant wind loading did we get any big avalanches. In other words, it currently takes a lot of snow on top of this breaking-down crust to produce results, and even then only after explosive charges are placed on the slope. A good example of this today was in the Heart, which is a feature to the skier’s right of Paradise Bowl, and avalanched about as big as anyone could remember – all on a day that otherwise produced few noteworthy results.
Now, about that right-side-up snowpack. Ideally, as a skier you want your snowpack to have its densest, strongest snow on the bottom, and then get gradually lighter as you approach the surface. This makes for great skiing, as you have soft snow to ski in on top, with a firm base on the bottom to keep the snow in place on the slope and you off of whatever ground features may be lurking below. In the avalanche world, weak over strong is good, and strong over weak is bad.
A (very) quick lesson in snow and temperature: Basically, weak layers develop when the snowpack is of insufficient depth to deal with a significant difference in temperature between its surface and its base. In this part of the world, ground surface temperature remains within a degree of 0 degrees C all winter long as a result of residual heat built up over the summer. Snow needs about 10cm of depth to cope well for every degree of temperature difference between surface and base (referred to as temperature gradient). For example, if your snowpack is 100cm deep, the temperature at the surface can be -10C or warmer without the snowpack suffering any ill effects. If the snowpack is shallower or the temperature colder, the snow can no longer maintain a gradual change in snow crystal structure from top to bottom, and weak layers begin to develop. (Many volumes of snow science have been published over the years, so obviously this is about as brief a summary as you’ll find on what can be a very complicated subject!)
A typical start to the season in this area involves a little snow mixed with cold temperatures, and any weaknesses in the snowpack that develop during this time tend to linger ominously throughout the winter, unless of course they are taken care of by avalanche control or warm temperatures. You’ve probably heard the term hoar, and there are two kinds – depth hoar and surface hoar. One type of hoar crystal can be those big feathery crystals you sometimes see next to a stream on a very cold day, covering not only the snow surface, but branches, fences, and the like. They are very fragile, and collapse as soon as you try to pick them up or disturb them. As the names imply, surface hoar happens at the surface, and depth hoar below the surface of the snowpack. Depth hoar happens when the temperature gradient is steep (shallow snow and cold temps) and surface hoar happens on cold days when there is a nearby source of moisture (not really relevant to a ski hill scenario), or during a cold, clear night. Depth hoar is a concern since the overlying snow is not well-supported. Surface hoar is not a concern as long as it is the top layer, but once it gets buried by new snowfall, it becomes a weak and unsupportive layer, just like the depth hoar.
Phew – enough about avalanches for now. Besides avalanche control, we also had a long day today of flying snowmaking equipment into place for the upcoming World Cup races, and my next post will be all about that, complete with photos. See you then…
