...Creep and Glide...

Rate of distortion is determined by a number of factors, including slope angle, temperature, snow type and density. Different rates of deformation within the snowpack create stress that can result in avalanches. These differences can be caused by rapid surface temperature changes or increasing load. They also occur at terrain features like convexities where the snow is "stretched" over the rollover.

A dramatic example of creep can be seen in the drooping, unsupported masses of deep snow that sometimes hang over the edges of roof eaves and off of narrow, horizontal surfaces like telephone lines and fence rails.

Glide is usually seen in the spring when melt water lubricates the ground, or in areas that have lots of sopping wet ground under a deep, warm, insulating snowpack. The slippery surface allows the snow to slide along the ground without breaking totally free of the surrounding snow. This process creates crevasse-like "glide cracks". These cracks tend to occur in the same places from year to year and can be very large. They can look like slab fractures or even glacial ice-falls. Like ice falls, the glide-cracked pockets of snow fail unpredictably, although failure seems more frequent when a warm spell turns cold.

Glide cracks should not be confused with shooting cracks that indicate instability in a dry snowpack.