Glacier ice is very similar to other forms of ice, although there are a few differences. All types of ice share the same qualities of density, viscosity, heat capacity and thermal conductivity. Some things that sets glacier ice apart — such as its larger crystals and slower rate of melting — are caused by the way that glaciers form. Over time, layer upon layer of continual snowfall causes the bottom layers of snow to begin breaking down and forming into ice.
More facts about glacier ice:
- Although it is not colder than other forms of ice, glacier ice does take longer to melt. This is because the ice crystals that make up the glacier are larger than the crystals found in regular ice. Ice melts from the outside in, so the larger crystals protect more of the surface during that process, which slows the rate of the melting.
- Glacial movement usually is described in two ways. Basal movement refers to the gradual forward progress of the glacier as a whole over land. Glacial creep refers to situations in which portions of the glacier move faster than other portions, such as the sides moving at a slower pace than the top and middle areas.
- A glacier retreat occurs when the ice begins to melt at a rate that is faster than the freezing of ice crystals, giving the impression that the glacier is moving backward.