Am I right in assuming that the snow in an avalanche behaves somewhat like a fluid?
If so, would it be possible to have some kind of flotation device that the victim is able to activate, rapidly inflating a large ballon (or something similar) from a canister of compressed gas, enabling them to float on top, or near the top surface of the flow?
BTW, I mean that they would activate it while the flow was still moving.
Methinks that the chaotic flow and moving mass of snow is going to make any buoyancy irrelevent, much like wearing a lifejacket while being at the center of a giant breaking wave.
I suppose we would also need to consider that snow is mostly air and flowing snow is even less dense (on average) - any effective buoyancy aid would have to render the average density of the whole apparatus (including the body of the victim) considerably less than the average density of the flow.
Won’t work. Objects are buoyant in liquids and gasses. Snow is neither. If you buried a balloon in snow, it would remain buried.
Did you read the question? I’m not talking about burying a ballon in a pile of stationary snow.
Buoyancy is a phenomenon of fluids - I believe it is the case that finely separated solids can behave exactly like a fluid when they are in motion.
Sorry X-ray I should not have been so snarky.
Darn, I typed a large reply but no one fed the hamsters so they ate it.
There is some evidence that the avy air bags give some protection, mainly from Europe where there are somewhat popular. They haven’t been use in the States or Canada yet to any degree. I have my doubts that they would provide any added protection in a serious avalache, but perhaps time will tell.
I think the theory is fine, I’m not sure of how they work in practice. Keep in mind that lots of the danger of an avalanche is trauma, in addition to the suffocation. Trees, rocks, ice can all cause blunt trauma and I don’t think the air bags provide much protection from that.
Indeed; it seems they would be of most use in a powder avalanche on a rather open slope. It also does seem a little strange that the flotation devices open on the back, floating you face down.
I guess if it attenuates one of the hazards (i.e. the burial, but not the trauma), then it is better than nothing, but maybe I’ll just stay at the lodge and drink Gluhwein.
As mentioned in the halfbakery link, this was done in a recent James Bond movie (“The World Is Not Enough”, apparently). Basically, the jacket was made of an array of inflatable pockets which, when inflated, formed a bouncy protective ball with empty space (not pressurized, though – the shape is held because the inflated outer pockets are somewhat rigid) inside.
It seems like one of the important factors in surviving an avalanche is going to be making sure not to get bashed in the head by the massive chunks of snow falling with you. I don’t think it’s like diving into a big fluffy pile of powder.
Wouldn’t work in my opinion. Perhaps a device that would create an inpenetrable cocoon would be more feasible.
The concept of floating to the top of a fluid avalanche flow is good and does work. The problem is that in practice there often isn’t enough time for it to work, or other extenuating factors (impact, skis on feet, etc) get in the way. While an avalanche is flowing it is possible to “swim” your way towards the top, and attempt to stay on top. Once the flow stops moving, things set up quickly, and that fluid medium becomes like concrete, trapping people in whatever position they end up in. Anything you can do to get your head above or near the top of the debris is a good thing. These air bags may help, at least to some degree.
The problem with trauma as I understand it isn’t so much the stuff flowing with you, though there is danger from that, but hitting trees and rocks in the path of the avalanche.