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"Dispersed" basal ice is formed in relatively warm ice where water flows between the crystals. |
The particular pattern or distribution
of debris in the basal ice depends on the process by which it was entrained,
and the way it was entrained depends on the temperature at the glacier
bed. Therefore we can use the characteristics of the basal ice to tell
us about the temperature of the glacier.
This reminds us of the idea of "process environments" that we discussed earlier in the lecture. We can use features in the landscape (or in the ice) to work out what processes were going on when they were created and thus to work out what environment they were created in. |
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"Stratified" basal ice is formed at a boundary between warm and cold conditions where water and debris freeze to the base of the glacier |