Thread: Avalanche Terrain

There is a big difference between skiing, and skiing in avalanche terrain, particularly in an avalanche start zone.

It seems like a 101 topic, almost ho-hum and not worth a thread. But it is almost the only near binary choice we get to make and still go skiing, the one decision we can really be confident in most of the time (with exceptions)

I wonder how many skiers and boarders are acutely aware of being in avalanche start zones? And does it matter to them that they are, beyond the popular fun factor that comes with that type of terrain?

If we are aware of it and still there, is is because accessible areas lack non-avalanche terrain which is also rewarding skiing? Hence our choices are limited and our risk taking is higher by default rather than choice? Or do we actively seek out start zones, despite plentiful options to avoid them?

Dumb questions?

Originally Posted by Hohes

There is a big difference between skiing, and skiing in avalanche terrain, particularly in an avalanche start zone.

It seems like a 101 topic, almost ho-hum and not worth a thread. But it is almost the only near binary choice we get to make and still go skiing, the one decision we can really be confident in most of the time (with exceptions)

I wonder how many skiers and boarders are acutely aware of being in avalanche start zones? And does it matter to them that they are, beyond the popular fun factor that comes with that type of terrain?

If we are aware of it and still there, is is because accessible areas lack non-avalanche terrain which is also rewarding skiing? Hence our choices are limited and our risk taking is higher by default rather than choice? Or do we actively seek out start zones, despite plentiful options to avoid them?

Dumb questions?

not dumb. def worth a tr. more so than geeky/science/charts imo. nttaww geeky stuff. i think that theres too much emphasis on the snowflake and not the terrain and routes of travel that the snowflake lays upon or is burried beneath the surface. i go by history. there are places in the high country where i've lived east and west that never have slid due to pitch and lack of terrain traps or certain wind loading. cons/high days? i just go to those proven places over and over without incident. fun skiing too above and belw treeline in those places as well. the moderate rating has always freaked me out the most and i've set off more potentially disasterous slides during times of moderate than any other rating.

avi terrain=

1) new slab
2) steep enough angle
3) sliding surface
4) trigger

take any one of the above away and it ain't avi terrain.^^^^^^^that is the extent of my geekyness, or lack there of and how i base my decisions up high.

rog

i have to admit that if i'm going to put in the effort of the approach, i'm looking for a reward on the descent.

so, before i've even left the house, i'm typically intending to ski lines that hold the potential of a slide

no matter how happy the snowpack is I'm always shocked when I ski cut that convex roll and shit doesn't start moving. Snow is pretty amazing stuff.

I do a lot of trying to get things to slide, on indicator slopes and stuff. Its pretty fun.

Great topic Hohes!

One factor that repeatedly catches my eye is what I refer to as "middle ground terrain". The Union Creek drainage near Crysal Mountain is a pretty good example. There are some pictures here:

http://avalanchesafety.blogspot.com/...ion-creek.html

The questions I have essentially mirror the question you posed at the start of this thread:

* What do you really know about the terrain in which you're traveling?
* Does the "visual appearance" of the terrain mask the actual degree of exposure?

When you use a computer to run statistical models of Union Creek, the numbers end up being very similar to terrain that is obviously much more dangerous. So, if a skier makes a choice to go somewhere that "looks" safer ( but isn't actually safer ) then it's just trading horses.



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Originally Posted by ak_powder_monkey

no matter how happy the snowpack is I'm always shocked when I ski cut that convex roll and shit doesn't start moving. Snow is pretty amazing stuff.

I do a lot of trying to get things to slide, on indicator slopes and stuff. Its pretty fun.

Here is one that went yesterday with a ski cut, after a big temp rise around noon.

It started up high where the brown dust in the snow help absorb the heat.

Everyone clear. Good thing, would have been hard to dig through that debris with a backhoe...

Will the heat up high in Co. solidify things if we get a storm cycle with some snow and cold temps? Do multiple days of thaw followed by cold make the lower week layers bond with days of sub 30 temps?

Obviuosly the opposite is true, the warming trend creates activity, in a big way as seen the pics above.

Originally Posted by Crampedon

Will the heat up high in Co. solidify things if we get a storm cycle with some snow and cold temps? Do multiple days of thaw followed by cold make the lower week layers bond with days of sub 30 temps?

Obviuosly the opposite is true, the warming trend creates activity, in a big way as seen the pics above.

if the current snowpack up high got saturated enough to consolidate and then freeze up with a cold shift in temps, then i would think that things would stabilize. once new snow starts to fall the new concern will be new snow instabilities failing on the new maybe slick frozen surface crust.

guess it depends on how deep the saturation goes and how cold the temps become. if both are marginal then you might be dealing with some bridging. bridging is tricky. tread lightly when crossing the bridge

rog

Hohes - Very good thread. Terrain selection is the one aspect of avalanche avoidance that we 100% control, and yet oftentimes it is still very complex. One difficulty I personally run into is what I would call "micro" changes in terrain. You can be setting a great skin track, in very dense trees (e.g., too dense to ski), avoiding avalanche slopes above and below and then find yourself in a small clearing. It looks harmless, is very small in relation to the larger terrain, surrounded by dense forest, but still has all the ingredients for avalanche terrain.

Even more so is other "micro" changes - e.g., small convex rollls, cross-loaded terrain impacted from different wind dynamics, etc... It is just a lot to process and something I would guess develops over time through travel in such terrain.

Originally Posted by Crampedon

Will the heat up high in Co. solidify things if we get a storm cycle with some snow and cold temps? Do multiple days of thaw followed by cold make the lower week layers bond with days of sub 30 temps?

The upper and middle pack should certainly become considerably more stable, but I don't expect the lower pack to stabilize much at all until the snow goes isothermal.

Every piece of terrain can be traveled/skied on the right day. Being relatively inexperienced in the backcountry, I find it relatively easy to make (what I perceive to be) the safest choice, but rarely is the safest choice of terrain also the most fun choice. What experience gives you is the ability to assume a reasonable level of risk that's appropriate for the conditions without being unneccesarily conservative. However, an awareness of your surroundings and a solid understanding of when to ski what is absolutely crucial.

One thing that has always puzzled me about gaining experience is how experience translates into better decisions. Tremper in his book talks about how most slopes will not slide most of the time, and the positive reinforcement that comes with surviving your outing, even if you made poor decisions and just got lucky.

So does experience simply add confidence to your potentially flawed decision-making? How does one gain the ability to make more sound choices?

Originally Posted by D(C)

Every piece of terrain can be traveled/skied on the right day. Being relatively inexperienced in the backcountry, I find it relatively easy to make (what I perceive to be) the safest choice, but rarely is the safest choice of terrain also the most fun choice. What experience gives you is the ability to assume a reasonable level of risk that's appropriate for the conditions without being unneccesarily conservative. However, an awareness of your surroundings and a solid understanding of when to ski what is absolutely crucial.

One thing that has always puzzled me about gaining experience is how experience translates into better decisions. Tremper in his book talks about how most slopes will not slide most of the time, and the positive reinforcement that comes with surviving your outing, even if you made poor decisions and just got lucky.

So does experience simply add confidence to your potentially flawed decision-making? How does one gain the ability to make more sound choices?

According to The Avalanche Handbook, a combination of targeted education and experience is the best way to learn how to make decisions.

To your question about experience and flawed decision-making: experience is not the same as skill. Being experienced means knowing how to do something. Being skilled means knowing how to do something the right way.

Do you want to be experienced? Skilled? Both?

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All IMO

Experience usually leads to more and more risk tolerance

More and more risk tolerance (and getting out more) leads to incidents.

Hopefully the incident doesn't kill either you or your partners

Which then drops your risk tolerance

But then if you don't give up BC skiing post-incident you'll go out again which will again up your risk tolerance.

The question then is whether you can learn how either (i) how to mitigate risk; or (ii) keep your risk tolerance under control. I suppose there's also (iiii) learn to accept the fact that you have high risk tolerance and are fated to die in the mountains.

and I submit that is all a very personal thing.


... and I forgot to answer DCs question. You can get out and trigger small avalanches on very small terrain to get experience in testing whether or not something will slide. eg ski cutting 5m slopes. Stomping on flattish or gentle surfaces to cause whumphs (which are after all essentially small avalanches), cutting cornices. But this is something to do very very carefully and in places where if you are wrong all you do is embarrass yourself