Extended Column Test - How to interpret?

Here's something I think about.

1. You have a high fever and can't keep down food or water.
2. Your doctor performs a complete blood count.
3. The test reveals normal cell counts.

What are your expectations? How do you interpret the results? How does your doctor interpret the results?

It probably means you have the flu and you need an IV if dehydrated. It could be early symptoms of appendicitis, but that usually means elevated white count. I don't  know what this has to do with an ECT.

jk Mike. Negative result don't mean your not sick.

Nice breakdown of potential scenarios that may effect a stability vs. an instability approach jd.  I was thinking it was just semantics, but your description brings it home.

Thanks for the list Lowell. It may also be helpful to mention for those who weren't there that the knotted string can be tied to the ends of two avalanche probes for saw-like use to create the test block.

Did a quick google; didn't find any of the vids Karl used, but there's a couple others. Here's one: Extended Column Test

www.turns-all-year.com/skiing_snowboardi...61.msg95316#msg95316

After thinking about it a little more, I remembered that Karl Birkland stressed how you mustn't use the test to verify stability. It can only tell you instability. So I added the following item to the checklist:

_Lack of failure doesn't necessarily indicate stability

I like the way you put that Lowell - "...doesn't necessarily indicate stability" (italics are mine)

While no single test can be used to determine stability, test like the ECT can be helpful in the process of confirming your theories about stability.  If all signs point to stability and the ECT also points to stability I would factor that result into my evaluations.  The key is to not give that test too much weight.  There are too many factors that could give you a false stable result (spatial variability, poor site selection, etc...)

Now if all signs point to instability and the ECT points to stability I'd probably just throw that result out.  I believe that is what Karl was getting at. 

What I use the ECT most often for is to track the trends in a layer of concern.  I've found it too be a good test to see if a layer is gaining or losing strength.  We often get surface hoar layers here on the east side of the cascades that can last for months.  These things can go dormant for a long time until there's finally enough weight to tip the scales.  The ECT is one more tool to help you keep an eye on these layers.

As far as physical tools go, I've found the long saw to be indispensable for the ECT.  The probe - cord combo works but doesn't give you as clean of a cut.  A 70 cm folding saw is cleaner and I believe faster than the cord.  Personally I prefer something stiff like the Brooks Rang Igloo 70 so the cuts stay straight.  Some of the long saws out there are a little too flimsy in my opinion.   

As far as physical tools go, I've found the long saw to be indispensable for the ECT.  The probe - cord combo works but doesn't give you as clean of a cut.  A 70 cm folding saw is cleaner and I believe faster than the cord.  Personally I prefer something stiff like the Brooks Rang Igloo 70 so the cuts stay straight.  Some of the long saws out there are a little too flimsy in my opinion.   

One point that Karl emphasized and even joked about was not filling our packs with more things. This of course is from the perspective of ski touring - I imagine if you're heli skiing or on a sled that this would be different. Seems he did most of his research using the probe/knotted cord combo. The beauty is that the only addition to your pack is a piece of cheap nylon (or whatever) string with a couple of knots in it.

A friend of mine was telling me that there was a new test for slab fracture propagation. Any one know if its true or what it is?

www.alaskasnow.org/wp-content/uploads/2011/01/Prop-Saw-Test.pdf

I think this is what you mean and related to the ECT.

One point that Karl emphasized and even joked about was not filling our packs with more things. This of course is from the perspective of ski touring - I imagine if you're heli skiing or on a sled that this would be different. Seems he did most of his research using the probe/knotted cord combo. The beauty is that the only addition to your pack is a piece of cheap nylon (or whatever) string with a couple of knots in it.

I agree that keeping your pack light is very important.  A heavy pack slows you down and wears you out, increasing your likelihood of needing all of that rescue gear, but the long saws are only a few ounces heavier than your standard saw.  Now if you are suggesting not using a saw at all, I think trying to do stability tests without a saw is like trying to carve a turkey with a spoon (gets the job done but its often a little sloppy).   I've tried the probe-cord method for everything from Rutschblocks to Compression Tests and it doesn't provide consistently clean cuts, which adds to the potential for inaccurate results.  Possibly the probe cord combo works better in shallower, lower density snowpacks but my results with it have been less than ideal. 

I'm always carrying a saw in the backcountry, whether I'm being dropped off by a helicopter or earning my turns (I spend approximately %95 of my time touring as opposed to heli skiing).  I actually find the saw more useful when I'm earning my turns because I have more time to do stability tests.  For me the extra 9 ounces are worth it.