The ratio of the volume of meltwater that can be derived from a sample of snow to the original volume of the sample; strictly speaking, this is the specific gravity of the snow sample. Freshly fallen snow usually has a snow density of 0. 07 to 0. 15; glacial ice formed from compacted snow (or firn) has a maximum density of about 0. 91. Values as low as 0. 004 have been measured. Compare water content, water equivalent.