January 10 - Snowpack

Rising Snow - Constructive metamorphism occurs when water vapor rises toward the surface, changing the snowpack's vertical structure.

Packed Snow - Firnification occurs when ice crystals melt, then refreeze, greatly increasing the density of the snowpack.

Unstable Ground - Snowpack is made up of layers piled on from each winter storm. Avalanches are likely to occur when weaker layers are buried toward the bottom of the pack.

(Photo by Tom Painter - Sampling of dust layers in the snowpack of the Upper Colorado River Basin by the Center for Snow and Avalanche Studies and the Snow Optics Laboratory/NASA Jet Propulsion Laboratory.)