diff --git a/content/notes/avalanche.md b/content/notes/avalanche.md index b960ccf2a..7990cd872 100644 --- a/content/notes/avalanche.md +++ b/content/notes/avalanche.md @@ -183,5 +183,37 @@ snowpack - formed by thin early season snowpack and cold temps - ![](https://i.imgur.com/bPduxfH.png) - creates vapour pressure gradient / temperature gradient + - ground is about 0 degrees c + - surface is similar to air temp e.g., -10c + - 10c per m gradient + - with a shallow snowpack and the same temps. the gradient is higher, causing _faceting_ creating sugary crystals + - deeper snowpack lessens the gradient + - less rapid vapour transfer + - - near surface facets - - surface hoar \ No newline at end of file + - hard to see + - small grains with sharp angles + - develop near surface during cold clear nights and warm sunny days + - surface hoar + - frozen dew + - large feathery crystals + - deposition of moisture on snow surface + - ![](https://i.imgur.com/pvsVjwG.png) + - ![](https://i.imgur.com/g3zwefO.png) + +weak ≠ unstable (weak + slab + steep) + +loading +- new snow + - rate of loading is important + - 2 feet overnight is bad + - 2 feet over a week is good +- wind + - can be 10 times faster than from sky + - cornices + - large drifts + - harder snow +- rain + - adds weight and stress and destabilises + +