Here’s a tabular form differentiating between glacier ice and firn ice:
|Glacier Ice||Firn Ice|
|Formed from the compaction and recrystallization of snow over time||An intermediate stage between snow and glacier ice|
|Typically found in the lower parts of glaciers or in ice sheets||Often found in the upper parts of glaciers or accumulation areas|
|Composed of densely packed ice crystals with minimal air pockets||Contains a significant amount of air spaces or bubbles|
|Appears blue due to the absorption and scattering of light by ice crystals||Often appears white or slightly opaque due to air bubbles and refraction|
|Exhibits high density and is more solid and compact compared to firn ice||Has a lower density compared to glacier ice due to the presence of air pockets|
|Exhibits minimal permeability to water due to the compact nature of the ice||Has a certain degree of permeability due to the interconnected air spaces|
|Generally characterized by slower flow rates and deformation compared to firn ice||May experience relatively faster flow rates and deformation compared to glacier ice|
|Typically forms deeper within the glacier or ice sheet, where pressure and temperature conditions allow for densification||Forms closer to the surface of the glacier or ice sheet, where snow undergoes compaction but hasn’t fully transformed into dense ice|
|Represents a more advanced stage of ice formation compared to firn ice||Represents an intermediate stage between snow and glacier ice|
|Examples include the dense ice layers found in the lower regions of glaciers or ice sheets||Examples include the porous and granular layers found in the upper regions of glaciers or accumulation areas|
It’s important to note that glacier ice and firn ice are part of a continuous process of ice formation and transformation within a glacier. As snow accumulates and undergoes compaction, it progresses from snow to firn ice and eventually to dense glacier ice.
The transition from firn ice to glacier ice typically occurs with the increased pressure and time associated with deeper burial within the glacier or ice sheet.