Slope Angle Affect on Compression/Extended Column Test


Original Post
BrokenChairs BrettC · · Sultan, WA · Joined Feb 2015 · Points: 245

I thought I'd share because I thought these studies were worth while. Also wanted to see if anyone else had similar experiences with being able to conduct pit tests from less dangerous locations to get an idea on the snowpack.

https://static1.squarespace.com/static/53fbfe1ce4b04ce86372f366/t/54289608e4b08f7343c91dbd/1411945992070/10_ISSW_ECT_SlopeAng.pdf

https://static1.squarespace.com/static/53fbfe1ce4b04ce86372f366/t/54287163e4b06b86fdabf37d/1411936611793/14_ISSW_BirkelandBairChabot_CT_SlopeAng.pdf

Gavin W · · Surrey, BC · Joined Feb 2015 · Points: 183

Interesting. I think that there are regional differences in snowpack variability as well (I didn't read the entire paper so they may have addressed this). Wind loading though can be dependent on slope angle, so you could certainly miss something by only doing compression tests in flatter areas.

Of course, the only thing that any compression test or ECT really tells you is what the snowpack is like at that particular point...

Derek DeBruin · · Unknown Hometown · Joined Jul 2010 · Points: 585

This is becoming pretty commonly accepted knowledge in the snow study community. You don't want to under do it and go super low angle, but a safer location that is still representative of the slope yields good data.

As Gavin, notes, this shouldn't be misinterpreted. A good example would be a lower angle pit at the top of a steep run. If that pit is subject to wind effect, radiation, etc. that differs from the run itself below, the results may not translate.

In an intuitive way, it makes sense for an ECT and PST. The only difference between cracking/whumpfing and an avalanche is slope angle. Cracking/whumpfing happen regularly on days of high hazard when you wouldn't think of riding anything steep just to confirm that an avalanche could occur.

Rui Ferreira · · Longmont, CO · Joined Jul 2003 · Points: 869
Gavin W wrote:Interesting. I think that there are regional differences in snowpack variability as well (I didn't read the entire paper so they may have addressed this).
Variability is present even within the same slope

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.715.1429&rep=rep1&type=pdf
Guideline #1: Don't be a jerk.

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