Stomping on a sawed cornice.

[hutash]

This just proves the adage.."Cornices always break further back then you expect them to."

That could have ended badly.

[LeeLau]

BFD - that's a hell of a picture

[upallnight]

just a quick reply as i've been inside all morning and need to get out for a quick ski tour...

one point i see i failed to mention earlier is that i have spoken with theo at length regarding this very video and situation. however, it was years ago (and this video was shot in.....2003 or 2004, i believe). i've also spoken with him at ISSW about his cornice-cutting technique.

he can shed more light onto the situation (it's trivial to find his contact information if someone is really interested).

i'll be sure to talk more with him about this in a couple weeks.

I thought it was just a probe pole with no saw.
e.g. remove pole handles and one basket, screw together and start poking the cornice.

he used a saw to cut a segment of the cornice in a specific way, which happened before the cameras were rolling. he may have been poking at it again with a regular pole. i haven't re-watched the video.

Problem with that method is if there really is high hazard, you end up being on the cornice while cutting of your small piece.

he knew exactly where he was at the time.

I think upallnight nailed a lot of it. - Its a known slope, fairly rated by the daily forecast and his experience as a local guide and snow expert for that season, and obviously expected to be stable based on them being up there in the first place (and clearly stable after it handles that huge cornice release)

we agree. (Stability is a relative term.)

What I would disagree with is that he expected that much of it to break loose behind him.

he expected to knock down the cornice. that was the intention of being there and doing what he was doing. i'm not speculating here about his intent -- that is what he has said he was there to do, and that is why the camera was rolling.

But, he was in the right location to knowingly ride it out to the right.
That was the cool part. If you are going to do something like that, think about your exit and where it might break and travel.
Much like a ski cut.

yes! his approach allows for a smaller section to fail first (briefly) and assist in the exit strategy. he was carefully positioned for the exit and pointed toward where he wanted to be.

can something go wrong? of course! that can happen in any situation.

I also am not sure he was doing cornice control work. - that cornice grows all season long and I'm not sure anyone feels the obligation to nock it down for public safety.

he was doing a demonstration and taking down a hazard on a frequently skied and often underestimated slope. you and i can disagree about the necessity of what he was doing, but it is hard to disagree that the slope (both the approach and the actual ski) is safer as a result.

he had a group of skiers with him that day who were being guided down the run, and they were safer for it.

Finally, to me it looked like a class. A lesson. A lecture.
An abbreviated and quick demonstration of cornice cutting in theory.

yes. not stated or covered specifically in the video. this was a part of his instruction for a steep ski camp years ago, he has said.

When he is cutting cornices in AK, I really doubt he is standing on the cornice and poking it with a probe pole.
Pretty sure he would use a rip cord or some splosives if he really needed to cut a big chunk off above a really suspect slope.

this is a very specific situation. each situation would call for its own technique. in AK, operations do not use explosives. there's a regulation (i think it's FS regulation) that requires an operation to stick with the same technique for avalanche control throughout a season. that means if you want to use one bomb, you've got to use them for the entire season, everywhere.

if you've been to AK, you know the vast terrain means this would be insanity.

good points.

Cool video.
Great example of cornice breaking behind you.
Sweet quarterbacking.

it broke where he expected. no quarterbacking on my end, just filling in some details about what i know of the slope and what the man has said about this event.

The graveyard is full of experts.

the graveyard is full, period. everyone should decide who their prophets are and act accordingly. personally, i like to examine new techniques and understand the motives...and then decide what, if anything, i want to incorporate into my backcountry routines. i assume you do the same.

Looks to me like it went bigger than he thought it was going to, but he was (correctly) pointed at his safe zone.

I think the most important point here is the difference between doing this in a "known" area versus somewhere "unknown". Cornice stomping is a pretty routine part of avalanche control.

he did expect the cornice to break. a cornice breaking is still a violent act, though, so in super-slow motion you definitely see some frames where one is out of balance.

I watched a video of someone cut a cornice have it break behind him forcing hm down the slope than ending up sprawled on the slope.
Yes and it still broke bigger than he thought and took him down the slope All the experience told him was that the slope was low enough angle he wasn't going much further.

well.....the reason he is facing the way he was and the reason he cut it the way he did (not shown in the vid) is that he expected it to go and wanted the whole thing to go.

i wouldn't exactly say that he was sprawled on the slope -- he's on his skis the whole way and puts a hand down for balance. that slope is rather steep (never put a slope meter below the area where that cornice is, but i'd say it approaches 50 degrees for that first turn and is less steep toward the camera. he just dropped 15 feet onto the slope in one turn onto the small rib and put a hand down.

isn't this what happened. Yes he choose a spot where the cornice was supported still he was forced onto the slope.

this is getting repetitive, but, yes, he anticipated going onto the slope and in fact needed to weight a small section of the cornice to get it to fail according to his system.

I really do not know what you are saying here. That we should cut all cornices as they are a threat to us on the slope? Personally my experience is unless they are actively loading or warming they really are not a threat. If you choose to walk out on them they become a problem. Personally having fallen through a cornice more than once I try not to mess with them.
Core Shot I believe there is a saw involved. I think it would be very difficult to cut a cornice using a probe. Also I really doubt he will use this method to cut cornices in AK. Big differnce from that cornice and one that has been forming all year in a place that gets 30' of snow. Also the Valdez heli ops do not blast.

i agree with you re: AK heli ops and cornices.

you made a point about how it is safer for you to use a rope and dig a pit on belay than cut a cornice. i accepted that as a safe(r) protocol.

since you live/work in AK, i'm sure you are no stranger to having a slope fail while digging a pit on it (or at least you know of experienced people who have had that happen).

while spontaneous cornice failure is unlikely without a trigger (warming, new snow, human traffic), it still is possible for a person to be on-slope, on-belay, digging a pit...and have one fail. a rope's not going to help much in that scenario.

i'd wager that dropping a cornice -- by any means -- means the slope will be safer afterwards.

i'm sure there are cases where skiers had a cornice fail above them. it can happen, though it sure is a rare thing.


<continued>

[upallnight]

<continued from above>

I agree with this but personally I do not try to avie control the BC. But choose to ski slopes when the conditions are safe. Also when using cornices as part of your avalanche control work I would think you cut them with each storm or wind event to keep them to a manageable size.

are you aware that the cornice featured in the video was not from one storm cycle? i can't recall either way, but i think that is possible, and in that event, theo would be 'cutting them with each storm or wind event' per your suggestion. just offering that up here.

have you ever done a ski cut on a slope? well, you've done some control work. acting as a guide and making a slope safer for clients to ski may involve different techniques from skiing something solo, but ski cuts, cornice drops, dropping a block of snow onto a slope, Z-cutting, etc. all add up to snow control.

again, as you probably often ski big terrain in AK, you know safety is relative, and small things can sometimes do quite a bit to improve the safety. i don't think anyone is arguing that these techniques are a substitute for digging a pit, knowing the snowpack, skiing smooth, having safe zones scoped, etc.

i think we probably agree more than disagree.

...it appears to more than one person that he got more than he expected when the cornice broke. I believe we have all come to that conclusion based on where the cornice broke, and his body language when it happened (... he wasn't looking down hill when it broke, fighting to keep balance, and ending up on the slope below partially on his side).

respectfully, i've said all i can on this subject. why not give theo a call and ask him? (seriously) or ask him @ issw @ squaw this fall. (again, i'm serious.) he is basically stationary on the cornice and has an exit strategy, but that doesn't mean he doesn't have to work hard to maintain control. you're looking in slow motion and analyzing frame-by-frame. he lands on his feet exactly where he expects.

you can decide this isn't safe for you, or isn't appropriate for your terrain, but at least invest the time to know how he cut the cornice and think about his exit strategy, etc., before you dismiss it.

To me, the fact that a known slope in known conditions can surprise you is exactly why I don't think this is good technique to use. That was the nature of my coments.

Do you still disagree with me? (I'm asking a serious question, not trying to be a douche). Thank you for shedding more light on the situation... it makes this discussion more meaningful.

i understand this is all for discussion purposes, so we can all learn. i respect your point of view and hope you know my comments are -- i hope -- pretty level. i've had the good fortune to speak with theo about this technique and this very video, which is why i'm responding in this thread.

because of those discussions and what i know of this terrain, i DO disagree with you in this circumstance. if you decide to speak with theo and hear his side directly, you might change your opinion (or might not).

intelligent people can disagree, and often do.

i'll still keep this technique in mind as *an option*. i think as backcountry users responsible for our own safety, we always need to maintain our options and continue to think about things in new ways. examining a technique in this way -- even if you think it is a poor one -- may make us come up with something new.

unfortunately, this video doesn't come with a 30-minute lecture on how to prepare the cornice to minimize risk as much as possible.

well, i think that's all i can possibly say on this matter, so i don't expect to reply any further in this thread. again, the source is available to you, if you are truly curious.

thanks for the discussion. hope everyone gets/had good turns today!

[Puffin]

Apologies for getting "heated" but my sentiment remains this same. this is a poor example at best of what to do in the backcountry. you shouldn't get your bc knowledge off the net but setting an example is setting an example.

This video posted insists this is controlled in the comments many times. It is not controlled. You should never be dropped onto the prone slope with the cornice. Period. It's dangerous.

30 years of bc experience isn't worth anything if it exhibits itself as hubris. The fact of the matter is that you drop a cornice because it stresses the prone slope much more than a skiier would. There is no other reason to cut a cornice. He cut it and dropped onto the slope. If there was a slide, he could have easily been caught and died.

I rountinely ski a bc area around me with a cornice at the top and maybe 20 chutes in a row under the cornice. Usually only one slides and is a pronouced slide path. I have ridden it over 250 times. This year the cornice fell in a spot that it always does but somehow the cracks propagated through mature dense growth into adjacent chutes. My point is, sometimes is breaks bigger than you expect.

What your boy Theo does here is just not a good example of how to drop a cornice. If he has been doing this for 30 years and falling onto the prone slope every time just cause he "can ski out of it everytime" well he's just lucky.

Use a cable.

[Dhelihiker]

nice blogs ^^


My #1 issue with this is what if I was on the other side of the peak, I drop in start skiing and some fucking asshole that watched a you tube video cuts a cornice off. When trolls set off control work, they have made certain that no one is below. You have no way of roping off a BC spot.

[phuongtim59]

I dont know what to say about this.

This poster of the video insists this is safe, but I think this is insanity especially on a larger cornice. Where I come from if you MUST cut a cornice you use a cable not this insane method.

What do you think...

YouTube- Cornice Break in Jackson Hole Backcountry

Great video! It's very nice and userful. Thank you so much for your post.

[inthemtns]

Great video. I don't think I will be using that technique anytime soon. As evidenced by these comments, there are just to many things to take into consideration.

[Alaskan Rover]

In my experience, I never trust a "dump" cornice...soft slab will bite your ass faster than a crack-whore. Sometimes it's just the "straw that broke the camel's back" kinda thing, and you'll never know where it's going to break away.

I think the guy was obviously trying a technique he'd used with success before, as it seemed a like a guide-training seminar of some sort...this time he got more than he bargained for.

He had obviously judged it safe for a cut, but I think he mis-judged the slab...people are not infallible and shit happens...this one just happened to be caught on video.

I think this video just underscores the fact that soft slab cannot be trusted emphatically. There is no precision with soft slab....there is experience and luck. That slab could have just as easily broke 2 feet in front of him and everyone would have been congratulating his success.

Shit happens...and sometimes it's filmed.

[BFD]

I found this glossary for you Alaskan Rover. You can start reading at the link.
http://www.avalanche.org/~uac/encycl..._avalanche.htm

[Alaskan Rover]

I found this glossary for you Alaskan Rover. You can start reading at the link.
http://www.avalanche.org/~uac/encycl..._avalanche.htm

BFD: I am in no way endorsing what the fellow was doing as being right nor safe. I never said that. But since I wasn't there, I cannot judge him, beyond the fact that he didn't expand his margin of safety. Shit happens, is all....just like on the bumper stickers.

By "dump cornice" I just meant a cornice formed by repeated dumpings of fairly light snow and of course wind over a short duration, rather than wind and slower accumulations of snow over over longer periods of time. Sorry if I used a term not officially recognized by snow scientists. It's just my own term, is all.


Do you honestly think that there is some sort of quantitative division line between hard and soft in the real world??? Like I said, I wasn't there observing those exact conditions, only he was. I think he judged that particular cornice and it's underlying layers to be of soft slab type, hence his being closer to the edge, anticipating that it would break below him. He was wrong.

That slab broke above him, but I think there is a hazy point between the characteristics of a hard and soft slab. Directly after the slab broke, the snow seemed of the soft slab category...fairly light new snow. One thing for sure...it looked pretty damn homogenous.

I think if there was ANY good vid that showed a slab that shared characteristics of both hard and soft, this vid would be it! It was a slab that broke above, but ALSO a slab that shared more characteristics with soft slab than with hard...just seeing what I could from the vid.

The guy obviously judged it as soft slab (and according to someone that was apparently there or knew someone there, he had tested the slab first, before the video...I guess his test told him that it had soft slab characteristics)...it defied him and whatever training he had and broke hard.

The fact that it shared one attribute with hard slab (breaking above the the guy) and MANY others with soft slab does not MAKE IT hard slab. It actually reinforces the fact that there is a great big wide fuzzy zone between hard and soft slab, where many characteristics are shared....."hybrid slab"???? Hermaphodite slab???? As you know, so many different factors affect layer adhesion, and those factors are continually morphing. They've got multi-million dollar avalanche modeling platforms that STILL cannot accurately present an infalliable slide model.

I think avalanche.org is probably the best readily avaible source for avi information...and like you, I have referred many people to it.


I still think that was soft slab that just happened to break sharing one hard slab attribute, that of breaking above. If the stresses and layering were just slightly different, it may have just as easily broken below.

We can go on and on about whether that was a technically a hard slab sharing soft characteristics or a soft slab sharing hard characteristics, but that would be pointless...just semantics.


I think we can agree, though that NO cornice and NO slab can be be fully trusted...and testing ANY cornice is dangerous work.

Looking at that vid, would I have done that test that way, or done it at all? No, probably not. That cornice would probably have been stable. But that's hind sight.

Me, if I am unsure about a cornice, and unsure about the safety of even TESTING it, then it's time to pick a different route.


Are you with the Avalanche Center in Cordova, by the way?
As long as I've lived up in Ak, Cordova is one place I've never been. You're lucky to live there. Myself, I hope they don't finish that highway there...the bridge is fine...it opens up new rec oppurtunities for the townies that don't have boats. But I wouldn't want to see the road completed. I know lots of townfolk want the road to increase "bidnes", and who I am to tell them they can't have their road...but a town changes its soul when a road comes in. In my neck of the woods (Homer and Seldovia), there are people that want to push a road from McNeill Canyon, around kachemak, past Halibut Cove, all the way to Seldovia and maybe even to Port Graham. Having lived on Jakolof Bay, I am worried by that type of thought. Do they still drive ATVs and trucks across that old bridge, or has DOT totally barricaded it now?

[summit]

Rover, it's not that i necessarily disagree with any one point you are making, but cornices by their nature are unpredictable and are NOTORIOUS for not behaving as expected particularly because they have variance in structure. Their variable behavior is hard to predict or detect until it is too late and that's due to the variable conditions under which they form. Therefor, doesn't it seems prudent to avoid riskier control methods like the one demonstrated here in order to avoid the occasional undesirable result, at least with cornices and runouts of significant consequence?

[CookieMonster]

I am confused by the lengthy explanations/justifications/hair-splitting in this thread. The skier in the video certainly looks surprised by the results, and I can't imagine that taking a ride, short or not, was in the plans. I've had my share of nasty surprises ... most of which were due to foolishness in one form or another. Making a mistake doesn't make someone intrinsically incompetent.

The hard slab/soft slab debate is confusing?

Cornice failures occur because cornices are usually overhung, and this makes cornices susceptible to tension fractures. The unpredictable nature of cornice failure is, as Summit explains, related to the varying hardness and density of the snow. The propagation potential of fractures that lead to cornice failure is directly related to the hardness of the snow and overall stiffness of the cornice. Fracture is less likely in a very hard cornice, but the failure is almost certain to be large. Fracture is more likely in a soft cornice, but the failure is not likely to spread.

[ColoradoGnar]

I would like to see that video if you have a link

[MagnificentUnicorn]

I really do think he intended to do exactly what happened after watching many times. He clearly intended to ski off the side of that cornice after doing his cuts and was not surprised by the cornice fall. He watches it fall and keeps his eyes on it the whole time as if evaluating the slope. He didn't lose his balance until the end when coming to a stop. How many skiers have had that happen when watching something else and coming to a stop?

[grskier]

I don't think you can deny that went bigger than he expected...

[Roo]

What I would disagree with is that he expected that much of it to break loose behind him.
But, he was in the right location to knowingly ride it out to the right.

At the TGR Jackson summit, Theo gave an avalanche talk, showed this clip and confirmed this very fact. He didn't expect the crack to propagate behind him in this manner and used the video to demonstrate that even with years of experience, there is still an element of unpredictability to cutting cornices. That said, his experience has mitigated a number of the allied dangers, as upallnight rightly points out.

[Alaskan Rover]

At the TGR Jackson summit, Theo gave an avalanche talk, showed this clip and confirmed this very fact. He didn't expect the crack to propagate behind him in this manner and used the video to demonstrate that even with years of experience, there is still an element of unpredictability to cutting cornices. That said, his experience has mitigated a number of the allied dangers, as upallnight rightly points out.

Thanks, Roo, for clarifying that.

I think it just goes to show that sometimes the difference between hard-slab and soft-slab is indeterminate, and that even after 20-30 years you can still get surprised by the action of snow. That's just the way nature is. Although avalanche science has made MANY improvements over the decades, you are STILL taking your chances out there...but isn't that part of the adventure of it? Sure beats an office desk where one's biggest physical danger might be falling out of one's chair.