Technical information, news, research, and opinion on avalanches, snow safety, and winter backcountry travel.

Tuesday, November 18, 2014

6 Signs of Exposure

Where am I to go, now that I've gone too far? — Golden Earring

Let's talk about terrain selection for a few minutes. A few years ago I wrote a rather long article on terrain selection, which I followed up with another article that explained the statistical basis for the model. I don't think anyone would argue about the importance of terrain selection, but the simple model of evaluating slope angles isn't quite enough.

With that in mind, I'm going to write a simpler post that discusses the six universal signals of exposure. The benefits of the six universal signals of exposure is that they're easy to use ( regardless of experience ) and they can easily be integrated into trip planning. This means you can evaluate exposure before you set foot on the snow.

The Model
LOCALE. A model for analysing exposure that gives you holistic information about exposure to avalanches.

  • Is line-of-sight limited?
  • Do local terrain features obstruct your line-of-sight to terrain above or below?
  • Is your uphill view blocked by rocks or trees?
  • Can you see all the terrain above and below or only some of it?
  • Pay attention and double-check your decisions when line-of-sight is limited for any reason.
  • Limitations to line-of-sight can reduce your reaction time to zero. ( I personally feel like this is one of the most important, and overlooked, elements of terrain selection. )
  • Is the terrain open enough to produce small, medium, or large avalanches?
  • Are there open breaks in the forest that allow snow to travel unobstructed to your location?
  • How much open terrain is present and where is the open terrain relative to your location?
  • Large quantities of snow can accumulate in open areas near mountain tops before an avalanche and in valley bottoms after an avalanche.
  • Is the terrain confined relative to the size or speed of an avalanche of any size?
  • Could a large, fast-moving avalanche overrun the valley floor?
  • Are you in a gully where escape from a small but fast-moving avalanche could prove impossible?
  • Small avalanches form deep deposits in confined terrain, such as hollows or depressions, where snow can accumulate.
  • Estimate your reaction time before something goes wrong and double-check your decisions if reaction time is short.
  • Reaction time is a very important part of your margin of safety because it can tell you a lot about the true degree of exposure for where you plan to travel.
  • Has snow accumulated above or below?
  • Avalanches often start where snow accumulates, and then run downhill where they deposit snow on the valley floor.
  • Are there obstacles above or below?
  • This includes cliffs, crevasses, rocks, and trees.
  • Obstacles above may block your line-of-sight, inducing hazard blindness, and can cause traumatic injuries during any phase of an avalanche.
  • On the other hand, obstacles can block or redirect flowing snow and may offer protection at your current location.
  • Is the terrain steeper than 30 degrees?
  • Avalanches start and rapidly accelerate on steep terrain.
  • Steep terrain produces fast-moving avalanches that can release above you and travel toward your location.
  • If you trigger an avalanche on steep terrain, you may be unable to escape from the flowing snow.
  • Steep terrain can limit your line-of-sight, and indicate locations suitable for sluffs, cornice drops, serac fall, or rock fall—all of which can start avalanches above or around you.

Wednesday, November 12, 2014

After All The Ambulances Go

After all this time, and after all the ambulances go — Arcade Fire

Are we putting too much emphasis on human factors?

Or, is the list a bit too short?

Should we expand the list of commonly accepted human factors to include a few unflattering, but honest, additions? I have a friend here in Seattle who is a registered nurse, and a few years ago he clued me in to a wonderful practice called evidence-based medicine. I've been thinking about that for quite a long time now, and I feel like I'm ready to open the discussion.

Powder Magazine has a new series on avalanches. In the first part, they discuss a serious accident that occurred on February 11th, 2014 in the Wallowa Mountains of Oregon. The discussion ends with the now-familiar ( to many ) discussion of human factors. To be honest, after reading the entire article, I was unsure why there was any need to discuss the human factors. The story could just as well have been titled "Pushing Your Luck In Shitty Conditions".

The second incident that I'm going to add is the accident that took place on December 16th, 2013, in the backcountry at Jackson Hole Ski Area in Wyoming. After that accident the survivors had many things to say about what went wrong, and their remarks included comments about additions to avalanche education. If I'd written an article on this accident, I'd have given it the title "The Link Between Incompetence And Death In The Backcountry".

I'm interested in why we so often choose to view avalanche accidents exclusively through the lens of human factors, and if we are going to do this, I am going to propose a few additions: stupidity, laziness, and incompetence. The long and short is that both of these accidents are textbook examples of what not to do, and no amount of education is going to overcome the inertia of laziness, stupidity, and unacknowledged incompetence.

Avalanche education gives participants a foundation with which to develop the scientific and psychological tools to travel safely in the backcountry. Yet you and I both know that many participants fail to follow established best practices, and that many accidents occur as a direct result of such failures. So while it might seem awful to propose adding "laziness", "stupidity", and "incompetence" to the list of human factors, are those words not applicable for backcountry skiers who fail to properly apply their training? Haven't we all walked down that road a few times? Those of us who have been lucky enough to survive should try to remember that it only takes once.

Before this comes across as judgmental or snarky, please allow me to add a few caveats: I'll put myself at the top of the list of people who have gotten themselves into trouble through laziness, stupidity, and incompetence. Second, if we aren't going bother challenging ourselves in this regard, then who will? No, really, if we aren't going to bother challenging ourselves in this regard, then who will? Why should we be afraid to call incompetence what it is, especially if it is our own.

( FULL DISCLOSURE: I was asked by the editor of The Avalanche Review to review the article about the Pucker Face accident. My remarks here are not a result of my participation in that regard. )

Tuesday, November 11, 2014

Snowflakes & Avalanches

It's hard to believe, but I've been nibbling away at this blog for five years now. The last few years haven't had a treasure trove of exciting posts because I've slowly been running out of things that I want to say about avalanches. So if anyone has any good ideas, please get in touch via the information on the About page.

That said, I trust everyone is ready to start skinning in hopes of powder. I'm ready to start skinning whether or not there's anything good to ski down, but I'm content to wait until the rocks are covered. Of course, once the rocks are covered, we have to start worrying about avalanches. So I'm going to wait a little longer and watch videos to help pass the time.

Here's one to get started: