Persistent Slabs
- Alpin
- Limite forestière
- Sous la limite forestière
- Probabilité
- Unlikely - Possible
- Taille
- 1–2
A weak layer of surface hoar/facets or a crust exists 20 to 35 cm down. This layer may be reactive to human-triggering where a slab has developed above it. Watch for signs of instability: whumphing, shooting cracks and recent avalanches.