| Term: | Weathering crust |
| Definition: | A friable surface layer, of reduced density, that develops due to small-scale variations of the melting rate of ice in the presence of cryoconite. Short-term measurements of surface lowering are unreliable as estimates of surface ablation when there is a weathering crust. The crust may reach a thickness of the order of 100200 mm over several days, only to be removed abruptly by rain or strong winds. |