How tight are safe trees? What is "near treeline"? Fat skis safe? How deep to effect?

Here's my take on fatter skis.

Many slides are propagated from a distance. This means there is a certain weight that will will overcome the tensile strength of a weak layer causing failure. So, the more weight, the more chance of propagating. So fat skis won't make much of a difference if you are propagating from remote trigger sites due to weight on a slope.

Another trigger is breaking through parts of a slab that were "holding" the slab from sliding on an already broken weak layer ie cutting loose a slab on a ski cut or sending something by skiing over a convexity. I think a couple inches of float extra is still splitting hairs unless you are getting those skis up to plane like a ski boat.

I wouldn't base my life or my buddies' lives on "couple weak layers here, good thing I brought the Birdos today".

But it goes back to all depends.

For the depth of concern, it really goes back to knowing the history of the snowpack. There have been some man eaters this season from the pnw over to MT that have 10 foot or more crown faces on some really weak layers. Most people only dig 6 feet or so. If you know of massive loading and some early season hoar, you might take the time to dig.

Trees-no way to be certain. Stuff slides in tight trees too. I like the addage open enough to ski, open enough to slide but it still depends on the snowpack, thermal affects of trees and sun, etc.

My .02 and answer to all of this is to follow general safety rules, know the snowpack and be humble.

Quote:

---

Originally Posted by Bart T

...
as for trees, I go by whether or not there are any branches on the uphill side, if not you're in a slide path. of course, i would rather be there than in some wide open bowl, but I'll keep my safety goggles on - ymmv.

---

this is what I was trying to get at before. The trees with uphill branches *seem* safe, but a 100yr. slide could get you right in the middle of it! Those class 3&4's in the PNW this year are just the animal I fear. I guess it depends on what exposure is above you when you're in the relative safety of trees...

I've always used flagging as a warning on where to put my routes, tracks, and safe zones.

I think we are starting to miss the point if one regularly focuses on the potential danger 100 or 500 year events in daily skiing decisions... which are by their nature irregular and extremely rare. You are more likely to have a tree fall on your head unless you seek danger during an activity cycle where conditions are running 100 year slides.

Agreed that conditions for slides that big are generally stupid obvious. It's the gray zones that'll get ya.

Quote:

---

Originally Posted by Summit

I've always used flagging as a warning on where to put my routes, tracks, and safe zones.

I think we are starting to miss the point if one regularly focuses on the potential danger 100 or 500 year events in daily skiing decisions... which are by their nature irregular and extremely rare. You are more likely to have a tree fall on your head unless you seek danger during an activity cycle where conditions are running 100 year slides.

---

yeah, true enough... the conditions are the first warning. This years Dec. 4th and Jan26th? PNW crusts are the red flags, and caution should be taken accordingly. Most years mature timber would be safe indeed, but by the looks of the downed trees up there - these are at least "75 year" events happening.

But you are right, if we wanted to worry by numbers, we'd all want to re-think driving to the slopes... or eating butter & bacon... or walking across the street without our helmets!!!

Yo jfost: not trying to talk shit, but the really big slides aren't "happening." They happened during multi-day/week-long snow events that featured new snowfall by the meter atop those crusts, then further new snowfall accompanied by warming. Seriously, not trying to talk shit, but that's how the big ones slid in Washington last month. There really wasn't any mystery about it. If you were trying to ski anywhere below slide paths at that time, then you were asking for it.

not a particularily valuable contribution to this thread but every time I see it the question that jumps to my mind is:

How safe are tight trees? :)

This was my first season on Pontoons, and the first season I've kicked off slides - two of them spooky and could easily have been leathal (I stayed inbounds after that first dumb run OB). But I think the unusual snowpack this year was much more of a factor than the fats luring me into questionable conditions.

having this thread bumped after summit's "Below Treeline Chuting TR" makes complete sense now :)