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ISSW, Innsbruck 2018. Alas, jetlag caught up and today I arrived late despite a few cups of power fluid. That means I missed “Localized Dynamic Loading in Extreme Snowmobile Maneuvers.” I do have the abstract. It is worth summarizing.
The gist is that the power and capability of snowmobiles now greatly exceeds most riders’ ability to assess avalanche danger. This especially in the case of situations such as deep persistent weak layers.
Getting scientific, a study showed that the snow machine exerts 2-5 times the pressure on the snowpack compared to a skier. In other words, want to go trigger an avy? The easiest way would be to boogie around on your sled. Though I’d imagine that skiers doing big cliff drops and high-speed turns might exert more force than this study used as a baseline. And telemarkers shifting all their weight to the rear ski when they ride out that big drop? Off the charts. For that study, ISSW Fernie 2020 will be worth attending.
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Next up, I did attend “Investigating Time Scales in Avalanche Formation.” Ever considered exactly when do avalanches run in relation to increased instability, say during a snowfall event? Sure, we count them when the storm clears or morning comes, but that is not the kind of scientific precision our modern avalanche scientists need for their efforts to explain the universe. To that end, these guys laced up a mountain with three kilometers of cable, connecting their sensors. It appeared to me that this was mostly a raw data gathering operation. All will evolve to something enlightening when they have more telemetry along with a multi-year span of data.
Ever wondered a big WHAT? when you’re getting mixed snow and rain? Scott Savage of the Sawtooth Avy Center spoke on forecasting mixed snow and rain… Some of his points that apply well to ski touring:
— Complex forecasting and hazard evaluation.
— Don’t try and solve problems you don’t understand.
— Know this is a challenging situation you can’t fit in a box.
— Perhaps just better to stay home.
Moving along to statistics! For some unknown reason, the conversations I had one-on-one during ISSW often turned to: How many backcountry skiers are there, anyway!? A couple of presentations focused on accident numbers, especially fatalities, but everything suffered without a way to normalize the results for changes in the number of participants. Black hole.
I suggested that researchers simply count cars at trailheads, from weekend to weekend, year to year. I’m willing to bet that would give an adequate take on growth rates, and could even be used to calculate raw numbers. Just having the growth rate would be a huge plus for statistical studies. I’ve estimated that the doubling rate during the past 15 years or so has been about 7 years. Rough guess, but counting cars at our local trailhead bears that out.
Which leads me to a few thoughts. Many of us are wondering how in tarnation we can have our enormous increase in backcountry users here in Colorado, and at the same time see an avy death rate that doesn’t steeply climb as well? (Other states, as well as the U.S. as a whole, may demonstrate this, more or less, but I’ll use Colorado as my point of discussion.) I believe some of this has to do with ski compaction of popular slopes, causing them to slide less. But that’s only part of it. I’m thinking a bigger factor might be that the majority of ski tourers are self-selecting terrain that’s been skied enough to be “tested” and obviously not particularly hazardous on a particular day. In other words, rather than looking for fresh pow on a pristine slope, where avalanche danger is relatively unknown, they go for the slope that other skiers have previously “tested.” I’ve observed this in the field and jokingly called it the sheeple principle (and been one of the sheeple).
A detailed letter from Birkeland, Greene, and Logan in Wilderness and Environmental Medicine describes the situation as follows, for the entire United States: “If we combine a conservative estimate of use increasing 8-fold since 1995 (Lou note, easily true) with our flat fatality trend, then our fatality rate has dropped dramatically. If our fatality rate had stayed constant, we might well be experiencing over 200 US avalanche fatalities each winter.”
What do you guys think? The concept of “self-selection for tested areas” leads to the next section, where my theory clearly did not apply.
“Avalanches and the Law” appeared to be a conference topic of interest to the WildSnow community. One of the more interesting presentations in that regard was titled “Ski Tours — A Legal Vacuum on Fashionable Peaks?” Presenter Klaus Paffeneder held forth with a real-life example. In 2017 an avalanche on the Bosenstain, in Austria. Apparently, this is what they call a “fashionable” tour, meaning it’s crowded, and popular for soloists. The avalanche was triggered near the summit by an unknown and took out three solo skiers. One was swept over a cliff and did not survive. Paffeneder used the accident to support questions that will clearly need answers as ski touring continues to grow in popularity while continuing to use “wild” terrain. I’ll paraphrase his interrogatives for clarity:
– By what standards or “how” do we judge the behavior of solo or group ski tourers? What is criminally negligent? What is socially unacceptable? What is normal?
– Does the general ski touring public understand how loading a slope or mountain with numerous skiers can change the hazard level? Is ignorance an excuse if you trigger an avalanche that takes a life?
– What legal or social responsibility do groups have for each other while backcountry skiing?
– Was the unknown person who triggered the avalanche criminally negligent, as there were skiers below? Were the uphill skiers culpable, in continuing upwards knowing others were above? Is everyone present obligated to perform rescue duties — legally, or socially?
WildSnowers, what is your take? If someone is above you on a peak and they trigger an avalanche that takes you out, any responsibility on their part? Yours? And again, could self-selection for “pre-tested” terrain be the cause of our odd avalanche accident statistics here in Colorado?
(Thanks Blase Reardon for getting me hip to the Wilderness and Environmental Medicine content.)
23 comments
The “sheeple principle” absolutely applies here. Folks gravitate to known, named slopes that are believed to rarely slide. As a consequence, when the number of skiers increase, these “safe” runs get compacted more and become even safer. I am one of the sheeple, but I do enjoy skiing an unknown line from time to time.
“snow machine exerts 2-5 times the pressure on the snowpack compared to a skier“. I’m no engineer, but this has to be low. With the extra weight, vibration, and especially the digging/ cutting action of the sled’s track, the number must be like 10x, no?
The fallacy of ski compaction: http://arc.lib.montana.edu/snow-science/item.php?id=458
There is plenty of evidence that early season cutting up of the snowpack does result in greater stability later in the season: http://arc.lib.montana.edu/snow-science/item.php?id=1683
but as for ski compaction – not so much.
Bard, pressure is defined as force per unit area, so the larger footprint of the snow machine mitigates the larger forces to an extent.
Forgot the quote marks on the mag article, we’ll fix soon. Can’t get to the admin at the moment. Lou
Paul, I get the surface area thing on low angle snow, but the force of the churning tread and the high velocity of the front skis in high marking and side hilling has got to be WAY more than a skier could ever generate. The exception being perhaps a young, powerful Lou:)
The legal vacuum of popular runs is indeed a huge issue. I know of, and have been on several tours where there were hundreds of skiers/hikers going up from the parking lot. They will obviously spread out to different micro locations but in at least some places, the common initial route is very exposed to several large avalanche paths that could easily be triggered by someone above and take out dozens of people. If this was the case I couldn’t possibly imagine how that one person could be blamed. Legally or morally. Just happened to be the one to trigger it, could be anyone else 30 seconds later.
There was a case a few years ago in carinthia with several parties on a slope (30+ people), someone above triggered a slide and several people got injured, no fatalities. If memory serves the person who triggered it got caught by the police upon reaching the parking but I can’t remember if there was any legal consequence. Might have been charged for fleeing the scene but I honestly couldn’t claim it was reckless behaviour or some such. Or at least the proof would have to be extremely persuasive (e.g. intentionally dropping a cornice with people clearly in view).
I’m afraid this issue won’t be resolved until a big, fatal event does happen.
About why popular slopes slide less: Our local avalanche reporter told me it was not so much compaction as the tracks breaking up the surface slab from a big slab into a bunch of smaller ones. It sounds plausible. He was likely referring to studies, but I do not know which. The conventional wisdom certainly is that popular slopes slide less than similar slopes which get skied less or not at all.
Having a lot of deadfall in the snowpack serves to anchor the lower layers. The downed timber keeps the base layers from moving as a unit, or at all, really. See? Deadfall can be your friend!
We don’t have any way to quantify this, but it feels like increasing access to (and riders taking advantage of) high quality avalanche education, forecasting, and rescue products must play a role in the reduced avalanche fatality rate. Thoughts?
Re the “sheeple” issue. I recall Mr Tremper in “Staying Alive in Avalanche terrain”, saying that one of the reasons for his continued survival in a fairly hazardous skiing life is that when in doubt, he always lets someone else go first. I follow this principle rigidly and am a happy (and alive) sheeple. Perhaps as a attitude it’s a little Darwinistic, I agree, but as backcountry folk we all know – or should know – about making our own choices and dealing with the consequences that may or may not follow.
Allan, Tremper’s including that in his essentials is indeed something to note. In my experience, there are certain personality types, ages, etc. who enjoy going first. I don’t mind that, used to be that guy myself, but unless you feel a compelling need to be the first on a slope, holding back, as Tremper alludes to, is any easy way to bump your safety level up a notch. Of course, as with the ski compaction issue, avalanches are fickle and sometimes happen after a few skiers have been on the slope. But in my experience most go with the first person if they’re gonna go. It’s wrong to call a slope “safe” after a few sets of tracks, but still ups your safety level if you’re not the first. Lou
https://www.wildsnow.com/14306/review-book-avalanche-essentials-tremper/
I hear the whole argument for “let someone else go first” but if you are so nervous of a slope sliding that you don’t want to go first, it seems cowardly to then allow your friend to ski the slope. I’m open to skiing slopes that are less than 100% in my mind but I certainly try to spread the risk through the group over the season. That would be a tough phone call to that persons love ones knowing you had doubts before the person dropped.
It seems to me like the big increase in popularity is due in part to ski touring now appealing to a bigger variety of people. In the past, my impression it was mostly “hard-core” skiers, but now I see lots of beginners or casual skiers who own touring gear and get out on a few tours per season. So these folks are not nearly as willing to accept travelling in riskier terrain.
Also, education has to have gotten better. Everyone is taking their avy 1 courses before even going out for a tour. And the classes are focusing a lot less on snow science experimentals (digging pits & tests) than on route-finding, weather, etc which is much more practical for all but the people venturing into truly unknown conditions. Plus, the weather and avy center forecasts are more accessible and easier to read.
These seem like bigger factors than skier compaction. I also don’t think skier compaction is really as big a factor in the coast ranges as in continental snowpacks, perhaps.
Counting cars at trailheads would work for many spots, but not for those with lots of snowmobiles or other users, like Vail Pass. I’m relatively new to the sport, so don’t have long term historical perspective like most on this forum, but even the “crowded” spots in Colorado are still pretty wide open a mile from the trailhead if there is no sled access.
I think one major factor at play is the large number of people who are only skiing familiar, quick roadside access locations that they hit on a regular basis. In my experience in some pretty crowded zones (Berthoud, Vail, Jones Pass), most people are within a half mile of the parking lot, and many are skiing lower angled runs. There are of course many exceptions and occasionally some very foolhardy behavior, but it seems like a small minority making poor decisions. At Berthoud the ratio of skiers within a half mile to those a mile or more from the trailhead has got to be 20:1.
Interesting discussion. My personal observations on my long-term favorite ski area (Mt. Rainier)–a narrow and perhaps atypical snapshot. In the 90s lots of XC and tele skiers skiing low to moderate slopes. Lots of emphasis on safe travel in the premier social group, the Seattle (and other cities) Mountaineers. Then the emergence of bulletin boards morphing into websites (for example Turns-all-Year) with reports and discussion of avalanches and opportunities for great skiing. AT taking off in the 21st Century leading to gradual increased risk taking. Lots of guidebooks. But a lot of attention given to the NWAC forecasts, avy equipment, and avy training. And the core skiers getting older & wiser & having influence on their peers and younger friends. Next extreme skiing movies and competition leading to freeride skiing and lots of serious risk taking, again by lots of skiers with considerable experience. Now (last 5 years) I see increasing numbers of millenials, veterans of ski-patroled lift-served skiing/boarding/riding, taking to the bc on their own, in their own personal groups, etc. and apparently many of whom are as ignorant and carefree as can be imagined. And followed by snowshoers–many of whom are indeed sheeple, following ski up tracks then trudging across, up, and down avy slopes, under cornices, etc. As a curmudgeon, I take photos and shake my head. I wonder if the rates are going to increase.
An image just popped into my head of two or three skiers at the top of a burly line saying, “go ahead”, “no you go first, I insist”, “after you, buddy”, lol.
I was that skier urged by my companions to go first! I did, made several turns, then abruptly disappeared as I fell off a six foot crown from a few days before. The light was flat, and I did not see it. The rest of the bowl’s descent required slaloming around the avalanche blocks. Not bad, actually.
Haha Jim, your friends probably freaked when you disappeared over the crown.
Sorry Rudi, I should have been a little clearer re the process. I would never urge anyone to go first in my place or expect them to sacrifice their safety levels for mine. And I expect that to work vice versa. Tremper is pointing out that it’s too easy to let group think, powder frenzy and the “I gotta be first, I gotta be first” attitude cloud common sense. Human emotion can get in the way of the science (inexact as it is with avalanche prediction) but you’re right, the scenario does raise huge moral questions.
Indeed, the “go first” issue is reminiscent of something you’d discuss in philosophy 101… In my view, if you’re up front about it within a group, e.g., “I don’t like going first, you guys like it, so go ahead,” then I don’t see any big moral dilemma. In fact, if you train up on your beacon technique and carry a high quality shovel and probe and first aid gear, and have your inReach or Satphone down pat, then you can view yourself as the safety backstop, a valid role.
This can work in reverse as well, I remember many times as a guide or when skiing with loved ones, when I went first to intentionally take on more risk.
Overall, yeah, wonderful to discuss. Thanks all of you for the astute commentary.
Lou
Re: being the first to drop in…
There have been plenty of cases of a slope avalanching on the 2nd, 3rd, etc. skier after the first skier made it safely to the bottom. Because of that, and knowing how long it can take for a rescuer at the bottom of a run to climb back up versus a rescuer at the top to ski down, I prefer not to be last.
re: “You go first — I’m doing you a bigly honor of first tracks”
I’m reminded of a flock of penguins standing on the beach, each trying to push one of their mates in first into the mouth of the waiting Leopard seal—
“Avalanches and the Law” , interesting topic.
We’ve been fortunate not to have seen more group A on group B mishaps. There’s been plenty of close calls in recent years. Peak 7 was ahead of its time.
Where’s it gonna happen? On the road, maybe. On the uptrack, probably.
“What legal or social responsibility do groups have for each other while backcountry skiing?” We’re gonna find out.
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