Out of Harm’s Way

After a very tiring week, I have successfully completed the AST2 course for expedition leaders.  This five-day course focused on advanced avalanche prediction, snow science and terrain and route management.  In other words, how to do your own avalanche forecasting and how to lead people through mountain terrain in a way that maximizes safety.

The first day I spent in a giant pit we dug in the snow to examine the profile of the snowpack.  By taking temperatures at many intervals of snow depth, you can determine the state of metamorphosis in the various layers of snow.  By identifying layers of snow, their crystal structure and their bonding, you can make pretty good predictions of snow stability at different slope angles.

Above is my snow pack analysis and by coincidence, the Parks Canada avalanche service conducted their own survey in a similar location the next day which was very similar to my own results.  The temperature gradient within the layers determines whether a layer gets stronger or weaker.  Complicating the matter is the fact that terrain itself influences the strength and weakness of this snowpack.  This is why we spent the week climbing up into the high alpine into complex, difficult and dangerous terrain to study first hand the intricacies of how to identify the myriad of dangers and safe zones.  

Here we are with veteran heli-ski guide and avalanche professional Cyril Shokoples discussing route strategy on the north face of Mt Crowfoot.  He was an excellent teacher giving clear and simple lessons that only decades of experience can generate.  Over the week, we each had to lead the group through very complex terrain features while justifying every step of the way to Cyril by explaining the rational for every move we take.  Not only that but we must be able to provide proof of our assessment of the snowpack at every moment through in situ testing.

We all found it very stressful to make these decisions while under the microscope of the instructor and our peers.  After all a bad decision would affect the safety of the group (although the instructor would have intervened.)  But in doing so, we all  gained valuable experience.  There’s nothing like learning by doing with the backup of an expert!

On day four, I led the group up to an unammed summit known only as GR248408.  Below is the GPS track.  The final ascent is on sun heated gullies which presented many different technical problems.I was rather pleased with myself in that I lead our group from the road up through a thousand vertical feet of trees and emerged in the alpine within 50 feet of where I wanted to be.  The complement I most enjoyed was when someone said they couldn’t believe we were at the top as it barely felt like they had climbed.  Safety aside, this meant I used the terrain to my advantage by allowing us to conserve as much energy as possible.  An elegant line up is something I am constantly trying to improve on.  This pride was brief though as we entered serious terrain features where critical decisions were necessary to remain safe.  

Above: Ewen studies the terrain as he leads us up  unnamed summit GR200375 on day 5.  While it may look pretty,  within this picture I can identify a dozen potential fracture points, three poorly supported convex rolls, two terrain traps, a hanging serac,  four run out zones and several dangerous cross loaded gullies.  But with careful geometry, all of this can be avoided and that is what Ewen is figuring out.

Above: At 10,000 feet above sea level, Gerry leads us above the Wapta on an unnamed summit face to face with Vulture Mt.

Above: Braving the summit windchill with the vast Wapta icefield stretching out to the horizon.  Vistas like these do not come easy!  Experience is slow to acquire and fitness alas, can not be bought at the hardware store.

Above L-R: South and North Rhondda, Mt Baker, Peyto Peak rise through the massive ice sheet.  Getting into places like this is truly amazing and is difficult to appreciate in the five or ten minutes you have to spare at the summit.

At the end of each day, we got the joy and excitement of skiing down through untracked snow back to the highway.  After a week though, my legs are waving the white flag of surrender and rest is in order for the next couple of days.  It was a great week of learning more skills and problem solving.  One of the other participants is part of my regular touring group so together we can add to our group’s knowledge base.

more pictures click here

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2 Responses to Out of Harm’s Way

  1. Curious to know how long it takes to do a paper analysis like the one in your first pic? In SCUBA there are some (far simpler) calculations to make with regards to the times and depths you will be diving, the time since your last dive and the accumulated CO2 in your body. Originally, it was done longhand on paper. Thanks to the proliferation of divers, there are many types computers to handle these calculations now (including ones you wear on your wrist and, of course, phone apps). Obviously, the conditions you experience in mountain terrain are complex with a lot resting on your judgement and evaluative skills, but computers must make the grunt work easier. Or is that just not feasible?

  2. daviditron says:

    Well, the curved line is the snow temperature profile at 10 cm intervals down to the ground so that’s difficult to mechanize. Also the layer widths are measured and the density, snow crystal type and size are all measured to make that chart. All these measurements are important. For example if two layers have a difference in grain size of more than a milimeter, they can form a weakness that increases avalanche potential. So It ends up being pretty hands on. The Parks guys have a template on the computer (the one in the pic) compared to my hand drawn version but thats where technology ends really.
    The whole analysis took me a couple hours, much of that was digging a pit big enough to have a clean “face” of snow to view and test in profile. As the snow is nearly 2m deep, this represents several tonnes of snow to move. As it was my first full profile, I’m sure I can do it faster next time.

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