Albedo is the percentage of the incoming radiation that is reflected off a surface. An albedo of one indicates that 100 percent of the radiation is reflected. Crevasses are open fissures in glacier ice.
Crevasses form where the speed of the ice is variable, such as in icefalls and at valley bends.
Snow has a density averaging about 0.1, firn has a density of about 0.55, and glacier ice has a density of about 0.89. The density of unmineralized fresh water is 1. Firn is old snow that has been recrystalized into a more dense substance. Snowflakes are compressed under the weight of the overlying snowpack. Individual crystal near the melting point have slick liquid edges allowing them to glide along other crystal planes and to readjust the space between them.