GL02 How are glaciers created?

Question 1

How does glacial ice form and what is the process called?

Answer 1

• Glacial ice forms through a process called accumulation. Precipitation in the form of snow falls on top of the glacier to form neve, and as the snow becomes more compacted after a year or more it is called firn.
• This compaction continues for hundreds of years with more and more layers added to the surface, a process known as diagenesis.
• The density changes over time from 0.05g/cm³ for fresh snow to 0.83-0.91g/cm³ as the firn becomes glacier ice, which eventually becomes so compact that the ice appears blue. In order for glacial ice to form, temperatures need to remain below freezing in the summer months, so that the snow does not melt