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

Thursday, December 6, 2012

Most Dangerous Equation

I was wondering, will you reach me?—Kylie Minogue

With some of the first great skiing weather of the season, I'd like to present an interesting concept that I found at Princeton University. It's worth reading the longer explanation, but I'm including a shorter version below:

The Most Dangerous Equation ( shorter explanation here ).

From the article:

It is no revelation that humans don’t fully comprehend the effect that variation, and especially differential variation, has on what we observe.

What can we take away from De Moivre? Variations increase as sample size decreases and variations decrease as sample size increases.

Think about this the next time you're evaluating conditions. Like most things related to snow safety, De Moivre's equation works both ways.

Thursday, October 4, 2012


I'm the weight, you're the kite—Metric

I'm trying to pick a theme for this year. Past themes have included uncertainty and complexity.

Maybe I'll choose psychology.

Anyway, you can look forward to expect a long series of posts while I think about a topics for the 2012-2013 ski season. Feel free to suggest topics if anything comes to mind.

In the meantime, think snow.

Wednesday, August 29, 2012

Phrase of the Day

Heart still beating but it's not working, it's like a million dollar phone that you just can't ringOne Republic

Happy Summer!

Found this on a popular social network.

Anyway, I think this image has a pretty nice, simple summary of the cognitive side of avalanche education. Feel free to add your own words...


Saturday, April 7, 2012

Unintentional Pseudoscience

As soon as I get my head round you, I come around catching sparks off you—The Jesus and Marychain

This post will probably be unpopular, but I'm going to publish it anyway. I'm sure that I'll lose a few readers, but I'm willing to take that risk in order to say something that I believe is incredibly important.

NWAC and/or Friends of NWAC and/or Huxley College of the Environment ( referred to herein as "NWAC et al." ) recently introduced a feature that allows you to visualise the current avalanche forecast as an overlay on a topographical map. I first saw this feature at the Northwest Snow and Avalanche Summit in November, and I was immediately uncomfortable. Rather than write a post about it last November, I decided to think about it for a while and see if my feelings changed.

They haven't.

Figure 1.1. "Danger Rose" map produced by NWAC et al. Unless asked, I won't post detailed criticism, but I will say that the map is utterly divorced from reality. Look at the huge sections of "moderate" danger. Does anyone really believe that avalanche danger is moderate everywhere indicated by the yellow overlay? If so, when is the avalanche danger moderate? This is a classic case of transforming data from a large scale ( synoptic ) to a much smaller scale ( meso or micro ) apparently without the additional data ( or procedures ) required to perform such a transformation with any reasonable degree of accuracy.

My "understanding" of the avalanche problem is "very advanced". By this, I mean that as my "understanding" has grown over the years, it has become increasingly clear to me that there are many things that can't be known. Perhaps that's why I so often write about uncertainty and complexity.

I recently wrote an email to a researcher who is a colleague of mine. In the email I discussed my travels through the network of avalanche phenomena, and about how uncomfortable it was to realise that many of my old observation tricks rested on empty assumptions. These discoveries made me realise that my record of making "safe decisions" is based in luck far more often than skill. From the email:

Funnily enough, it only took a few videos to convince me that many of the data collection/observation techniques that I've been using in the backcountry are probably very weak, and possibly very dangerous. The inescapable conclusion is that natural phenomena, such as the chaotic interaction of air masses and rough mountain terrain, are complex enough to DEFY our ability to make anything beyond what amount to very simple inferences.

The fact of the matter is that the science of terrain, snowpack, and weather are not nearly advanced enough to allow anyone to create detailed avalanche forecast maps for a large area. NWAC et al. have gone through the motions of at least twice disclaiming the inapplicability of the maps at small scales, even while the map presents the data at small scales. Yes, they've limited the zoom feature, and while I certainly believe that they're trying to do the right thing, the fact of the matter is that the science says this map is dangerous and inaccurate.

I believe that a professor at the Huxley College of the Environment handled the programming, and since I'm not at all sure of his background, I'll keep my comments narrow: the capability to make a map of the avalanche forecast does not mean that it is a good idea, and anyone with a reasonable, working knowledge of the scientific realities of avalanche phenomena should understand why.

Figure 1.2. "Danger Rose" map with single kilometre quadrants. It's very obvious that this map inappropriately presents data at the kilometre and sub-kilometre scales. Each kilometre quadrant is 20x20 pixels, which means that each pixel is 50 metres. 50 metres IS approximately the scale of a single slope. Even though NWAC doesn't allow additional zooming, I think it's fair to say that the danger rose map presents data at the synoptic, meso, and micro scales.

The map CLEARLY shows a synoptic scale forecast that has been inappropriately transformed to the kilometre scale, and possibly to the slope scale as well. Think I'm just being picky? Ask yourself a question: where are the data for each coloured point shown in the map and how were the data generated?

In reality, there's no actual data for most of the points in the map, and the lack of a disclaimer for this "little" fact is misleading AT BEST. Shouldn't the disclaimer say something like "We made this map using data from a variety of computer models and a few weather stations. Even though the map looks complete, we actually have no data for most of the forecast area." That would, at least, be honest.

I feel perfectly comfortable assigning the bulk of the criticism to Huxley College of the Environment. Their logo is featured prominently at the bottom right corner of the map, and they handled the programming. It's Huxley's responsibility to get the science right, and this abject failure rests solely at their feet.

The science of avalanche phenomena tells us unequivocally that such maps cannot be accurate given the current state of the art. I understand the desire to make things easier for people to understand, but this is not the right approach. It's one thing to implement something as an experiment, or even as a tool for professionals, but it is another thing entirely to make it available to the general public, who may not understand the limitations.

As it stands, scientific impossibility relegates this map to the realm of unintentional pseudoscience. NWAC et al. should remove this feature from their web site immediately, and the good folks at Huxley College of the Environment should get a better handle on the science behind avalanche phenomena.

Friday, April 6, 2012

Happy Trails

It's that time of year... time to think about long trips that involve skiing big mountains. I've certainly had less to say this year than in years past, but I hope that what I have written has been useful.

I have one more post for the season, and I'll be publishing it in a couple of days. It probably won't be a very popular post, but I'm not all that concerned with popularity.



Monday, February 20, 2012

More Suffering

You gotta know when to hold 'em, know when to fold 'em, know when to walk away, know when to runKenny Rogers

On Sunday, four people were killed by avalanches in Washington State. I won't armchair because it only adds to the suffering for survivors.

But there's another side to the story, and it's that not everyone died. Here's a post from Turns-All-Year in which a local backcountry skier describes their experiences in/around the backcountry near Crystal Mountain Ski Area.

Yesterday was really bad. Condolences.

In the backcountry near Crystal, we triggered two slabs one 80-ft wide with 12 inch crown. No burial. The one strong warning we observed.

Then later triggered a 250-ft wide 24 inch crown. Brought down the whole small (what we thought was mellow angle) bowl, on us as we were skinning up. All of us were buried. Two partial, chest +/- deep. One burial a full 4-ft deep. Beacon and probe and quick (5-6 min.?) uncovering of the 4-ft deep burial saved a life. We all skied out with no major injuries.

A crazy day indeed.

In other posts, I've written that there is a significant difference between experience and skill. Skill means knowing how to do something properly. The tale from Crystal Mountain is a testament to the ugly possibilites that arise when you take a low skill approach to backcountry skiing.

As always, as I've written so often, it's so easy to focus on the physical and kinesthetic aspects of backcountry skiing, but the underpinnings of the sport are almost entirely cerebral.

That's why you have to manage your state of mind.

Now every gambler knows the secret to survin' is knowing what to throw away and what to keep.

Friday, February 3, 2012

The Root of Suffering

Terrain + Snowpack + Weather + Human = Desire * Uncertainty

I've updated my recipe for decisions ( directly above ).

So I'll spare you the long-winded rattle about risk management, because what does all that stuff really mean? If you want the long version, read my Backcountry Recipe Book post. For follow up reading, check out Lynne Wolfe's interview in The Valley Citizen. Lynne is brilliant ( as usual ).

The long and short of it: no matter how we approach the world, it's up to us to proactively manage our state of mind.

Wednesday, January 25, 2012

Does Size Matter?

I feel like a broken record.
I feel like a broken record.
I feel like a broken record.

Does size matter?

Here's an excellent video of a small avalanche.

Watch the video and draw your own conclusions about the relative safety of a small slope.

The slope in the video provides a perfect example of the concept of consequences. For any slope that contains enough snow for a complete burial, consequences are already at maximum regardless of the size of the slope.

Thanks to whoever posted this video. I assume that your friend is unhurt, and if so, it's great that you were paying attention because it doesn't take very much for situation like this to have an entirely different ending.

So, with that in mind, does size matter?

Monday, January 23, 2012

Does Size Matter?

Hello from bed.

Two weeks of cold, sinus infection, and ear infection have kept me busy. It's even better when your family catches the same cold, and everyone gets sick ( and cranky ).

In light of the recent snow, and in light of some recent close calls, I'm going to post a link to a post I wrote in March of 2010. This post discusses the relationship between terrain size and our perception of hazard.

This is an important topic because, at one time or another, we've all traded horses and chosen smaller slopes that we thought were safer. But as the USFS pamphlet on avalanches clearly states, about half of all avalanche victims are killed by slides running less than 300 feet ( 90 metres ) slope distance.

Does Size Matter?

And while we're at it...

Let's have a quick refresher on uncertainty.