Glossary

Credit

Mark Bender

A glide slab is a cohesive slab of snow, often consisting of the entire snowpack, that lacks significant support of friction from the bed surface beneath it. The slab “glides” slowly downslope as a whole unit, slipping over a smooth ground surface, or sometimes a hard ice crust or glacier. Grass slopes, smooth rock slabs, or areas exposed to geothermal heat are common areas for glide slabs to occur. 

Glide slabs are often visible by the presence of glide cracks, which form as the slab begins to tear away from the surrounding snowpack. When the strength of the slab is finally overcome, it releases as an avalanche.