Tuesday, January 23, 2018

Swimming in Snow

[Prepper Journal] In a past life I was involved in the Avalanche Survival Classes The Sierra Club taught. This was back when their ranks were filled with outdoor enthusiasts focused on survival and conservation as opposed to politics. Then the organization understood that hunters and fishermen and mountaineers were among the most aware and responsible of people in the wilderness and left the smallest of carbon footprints. As preppers we may end up in the mountains and snow and the physics of snow are another thing to understand to give ourselves the best chance at survival.
While this was all on-piste skiing, the ski patrol was always dealing with the clown that went off-piste and got into trouble. (A note: the term is loosely used to mean within the bounds of a ski area and outside the bounds of a ski area.) Part of the certification process from the Professional Ski Instructors Association (PSIA) was to recognize avalanche potential, on or near ski resorts. As a scientist, I became very interested in this as it was a real world application of some highly technical textbook stuff – a lot of physics as to the bonding of materials, and a lot of fluid mechanics. Working in that alpine environment gave me my first real world experience on how to be “detectable” when you are off the grid. Being buried under a few feet of snow somewhere, anywhere in maybe 200 acres of avalanche slab run off is one hell of a position to end up in. Of course, there were specially trained dogs, transponders and other technical devices to assist…somewhere. Maybe drinking hot cocoa at the warming hut and seldom less than 5 minutes away. I find this interesting because unlike a SHTF scenario your goal here is “how do I QUICKLY get found when I am buried alive!”
Anyone who lives in an area where snow is something to deal with knows the differences in the construction of the snow crystals caused by temperature and humidity. Colder and dryer makes for lighter snow with limited bonding capabilities. You have all seen this in films of skiers blasting through waist or chest deep “powder” with ease, or in trying to make snowballs. On the other hand warmer and higher humidity give you what we called “Sierra Cement” though it has many names, not all of them as complimentary, especially if YOU are the one who has to shovel the porch, walk and/or driveway. The “average” ratio of snow to water is 1:10 – 1 inch of water produces 10 inches of snow.
Well as you all know sometimes it snows when it is 8 degrees F with a relative humidity below 15% and sometimes it snows when it is 30 degrees F with a relative humidity of 38% or more. (Floridians will shake their heads at these humidity numbers.) What this does is produces layers in any mountain snow pack of dry non-binding snow between layers of wet heavy bonding snow. Now take this snow pack and pitch it on a mountain slope. The steeper the slope, the more likelihood of an avalanche. The reason that a lot of areas that look so tempting around ski areas are “off piste” – closed to resort users. And the exact same reason some idiot is going to chance it to “cut first/fresh/new tracks”. Read More