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Ice Ring Analysis

Ice Octopus Pictures > Lake star examples and analysis > 10.jpg

Contraction cracks (wet cracks) cracks are a common feature of ice sheets.  They form in the evening when things are cooling off. These cracks are common.  If they get a snow  layer on them (snow storm or drifting snow) the can be develop a buoyancy instability and the crack takes on the features of a lake star.  The crack is the up-flow hole and the dark feeder arms are arranged along the crack.  The arms are smaller and more numerous.