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Higher Elevation slab?

  • Joedabaker
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01 Jun 2012 14:46 #105531 by Joedabaker
Higher Elevation slab? was created by Joedabaker
Just throwing this out there since the 7000ft and below snow pack seems to have drained to the base by now if there are any thoughts on the slopes reacting on the higher elevations as the warmer snow levels advance their way up to 10 or 11,000 ft. IE...draining down to an ice lens or weak layer from the winter and having large scale failure of the snowpack.
Beside the prerequisite dangers of false bridging on crevasses, rock fall and cornice collapses, does anyone feel there is potential snowpack failure on weak layers and some large scale action as the higher elevation snowpack evolves or should I say dissolves in areas like the Inter Glacier or Frying Pan Glacier?
I have seen some pretty ice glazed slopes over there from Crystal during the ski season.

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02 Jun 2012 08:35 #105543 by ron j
Replied by ron j on topic Re: Higher Elevation slab?

I think that is worth serious consideration, Joe.
I was just thinking this last week that I may just dig a few pits in search of those types of layers before I retire my avy gear for the summer/fall corn season.

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  • garyabrill
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04 Jun 2012 16:09 #105645 by garyabrill
Replied by garyabrill on topic Re: Higher Elevation slab?
Not sure about that, Joe, but here comes another foot or more of new snow down to 5000-5500'....

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  • Joedabaker
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05 Jun 2012 07:08 #105674 by Joedabaker
Replied by Joedabaker on topic Re: Higher Elevation slab?

Not sure about that, Joe, but here comes another foot or more of new snow down to 5000-5500'....


Well I'm not sure either, but the possibility does seem applicable given that higher elevations tend to progress into the spring season later than lower elevations. What helps the snowpack is that it is higher and the potential for refreeze is much better than lower elevations that remain warmer. Thus slowing the progression of meltwater.
I saw recent pictures of Shasta in a trip report where there is a huge hangfire on it's face. Not sure if that is a result of what I'm talking about since there is more warming on southern volcanoes and a better chance of percolation. I would assume hypothetically the possibility exists. Unless of course you can explain why it would not?

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  • Amar Andalkar
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05 Jun 2012 10:28 - 05 Jun 2012 10:36 #105685 by Amar Andalkar
Replied by Amar Andalkar on topic Re: Higher Elevation slab?

I saw recent pictures of Shasta in a trip report where there is a huge hangfire on it's face.


I just skied from the summit of Shasta last week, and drove around taking high-res photos of several other aspects. If by "huge hangfire" you mean a large avalanche crown, I saw no such thing anywhere on the south, SW, west, NW, or north aspects of Shasta right now. All recent TRs which I have seen have come from routes on those aspects. Can you link to the specific TR or photo?

However, the large semicircular bergschrund which spans the top of the Bolam Glacier on the north side of Shasta is often mistaken for an avalanche crown. I wouldn't be surprised if that is in the photo you saw.

Over the years, I've found that the majority of distant-view reports of large avalanche crowns on the Cascade volcanoes were actually bergschrunds being mistaken for crowns. The report in mid-May of a large crown spanning the entire width of the Park Headwall on Mount Baker practically screamed out "bergschrund!" instead of avy crown, as the person posting the report posted no photos of the "crown", and a large bergschrund spans that entire face. Perhaps there was in fact a crown and not simply the bergschrund opening up across the entire Park Glacier face due to 4 days of intense heat, but without high-res photos, the safest and most likely conclusion would be that it was the bergschrund being mistaken for a crown. If someone does have photos of a crown spanning the entire Park Headwall in mid-May, please post them, I want to learn more about any such event.

I'm referring to this post:

I was skiing all over the Mt. Baker Ski Area yesterday (5/15) and got a great view of Mt. Baker and the Park Glacier.  Last Friday (5/11) I saw the great tracks down the Park; yesterday I saw a huge crown across the entire Park headwall and assume the entire thing had ripped over the weekend or on Monday.

Similar aspects further around towards the Boulder Glacier showed large crowns also.

"The heat is on..."

which was also quoted in the Weekend Avy Forecast thread.

I observed no avalanche activity or instability of any kind at high elevations on Mount Rainier that weekend (see my May 12-13 TR ), and I would expect that elevations above 9-10K on Baker were similarly unaffected by the heat, so a massive slide (and multiple other large slides) would be shocking. During those sudden spring heat waves, my own experience has shown that the avy-safest places in the entire Cascades are usually at high elevations on the volcanoes, since that is where the degree of warming is the least and where temps barely rise above freezing, even when it is suddenly 60 F at Snoqualmie or wherever, and everything in sight there is wet-sliding.

Last edit: 05 Jun 2012 10:36 by Amar Andalkar.

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  • T. Eastman
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05 Jun 2012 11:25 #105687 by T. Eastman
Replied by T. Eastman on topic Re: Higher Elevation slab?
Amar, I know what I saw and I frequently observe that side of Baker. I also know about the bergshrund and considered that in my note. Others beside you are capable of making astute observations...

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  • Amar Andalkar
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05 Jun 2012 12:26 #105691 by Amar Andalkar
Replied by Amar Andalkar on topic Re: Higher Elevation slab?

Others beside you are capable of making astute observations...


Well, as usual, it's hard to comment or even ask for clarification about anything online without offending someone, and then getting a snippy response. I'm sorry if my comments and request for photos of what sounds like a very exceptional avalanche offended you, that was not my intent. Would like to see photos even more if it was definitely an avy crown. That Park Glacier bergschrund is definitely among the ones most commonly mistaken by many for an avy crown, though.

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  • garyabrill
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05 Jun 2012 15:34 #105694 by garyabrill
Replied by garyabrill on topic Re: Higher Elevation slab?
All I'm really saying, Joe, is that after mid-May or so, I usually don't worry about deep instabilities since they would be hard to trigger and you would never really know, anyway. So, I worry about recent snow and natural sluffs especially in gullies and glide avalanches off rock slabs. The latter two types of naturals are the only ones by this time of year that seem to be probable enough to be a concern. Otherwise, I would obviously be careful around cornices (especially above them). I'm also careful when there is much exposed rock since snow comes off rocks (as do rocks!). Rocky areas are also problematic as far as the effect on warming the snowpack with the potential for deeper slides.

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  • Joedabaker
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05 Jun 2012 18:23 #105698 by Joedabaker
Replied by Joedabaker on topic Re: Higher Elevation slab?
You are probably right Amar it is a bergshrung. I used the word hangfire because it looked as though something more may bust off that sucker.
Gary thanks for the response. I to was thinking that it does need a trigger after i posted the reply. But great follow up.
It is strange to me that there is more attention at lower elevations than at higher when it comes to spring depth failures.

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  • Joedabaker
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05 Jun 2012 18:30 #105699 by Joedabaker
Replied by Joedabaker on topic Re: Higher Elevation slab?
And also the reason I ask is that I can never learn enough about snowpack.
I've seen things that I would have never predicted.

And I rarely climb or ski above 10,000 ft so I have no history, just a lot of assumptions.

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  • CookieMonster
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06 Jun 2012 14:32 #105714 by CookieMonster
Replied by CookieMonster on topic Re: Higher Elevation slab?
To answer your original question, yes it's possible to encounter leftover weaknesses in the snowpack at any elevation where snowpack is found.

I think your question is a bit more specific, as in "do these weaknesses exist right now". I'd say, yes, you could probably find patches of weak snow buried in the high elevation snowpack at certain aspects and elevations in the Cascades, and you can probably trigger avalanches. Is this an exceptional year for such weaknesses? I'd say no, at least not from what I've seen and heard. However, like you, I've observed enormous patches of shiny surface snow on the east side of Rainier, and I have wondered about it. That information would certainly lead me to be cautious were I to travel in that area.

Finally, whether or not any weaknesses are widespread is a bit moot in my opinion because it doesn't take a very large area of weakness to produce an avalanche capable of injuring, burying, or killing a skier, especially in certain situations like "small avalanche + crevasses nearby".

1. Protocol doesn't change. If you suspect weaknesses, get out your shovel and dig.
2. If you find weaknesses, adjust your travel plans and expectations accordingly.
3. Make conservative decisions if you are uncertain about the distribution and parameters of weaknesses.

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  • avajane
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03 Jul 2012 18:20 #106814 by avajane
Replied by avajane on topic Re: Higher Elevation slab?

Just throwing this out there since the 7000ft and below snow pack seems to have drained to the base by now if there are any thoughts on the slopes reacting on the higher elevations as the warmer snow levels advance their way up to 10 or 11,000 ft.  IE...draining down to an ice lens or weak layer from the winter and having large scale failure of the snowpack.
Beside the prerequisite dangers of false bridging on crevasses, rock fall and cornice collapses, does anyone feel there is potential snowpack failure on weak layers and some large scale action as the higher elevation snowpack evolves or should I say dissolves in areas like the Inter Glacier or Frying Pan Glacier?
I have seen some pretty ice glazed slopes over there from Crystal during the ski season.


I think that this year that is a concern. I know that up north in Whistler they get "grounders" often after the ski area closes in big snow years.. I've seen pictures of huge slides going full slope on Sudans as well as Flute and all the way to Lesser Flute. These areas are in the 6,000 - 7,000' range and will fail after a spell of really warm days. I'm thinking that being careful during the next few hot spells would be a good thing... I will not be camping out at the bottom of a steep slope in the late afternoon on a hot day.

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