glacial system, budget and net balance
- Created by: Ali Bland
- Created on: 16-03-15 19:43
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- Glacial System
- The main input is snow
- The main outputs include ice and meltwater
- Over many years of snow being compacted, it gradually turns from ice crystals to a clear glacial ice
- The weigt of the compacted ice combines with gravity to make the glacier move slowly downhill
- As it does that, it transports sediments and erodes the valley
- The glacial budget
- The boundary where gains & losses are balanced is called the equilibrium line
- Variations in the glacial budget may result in this moving either up or down the glacier, causing the snout to advance or retreat
- The glacial budget varies during the course of a year
- The two zones
- Ablation zone
- Where there is a loss of ice during a year
- Here the losses (melting, evaporation) out do the gains
- Where there is a loss of ice during a year
- Accumulation zone
- Snow accumulates and forms ice
- Here the inputs (snow & avalanches) out do the outputs
- Snow accumulates and forms ice
- Ablation zone
- In summer ablation will be its higher, because a rapid melting of the ice
- In winter, accumulation being greater than ablation
- In summer ablation will be its higher, because a rapid melting of the ice
- The boundary where gains & losses are balanced is called the equilibrium line
- Net balance
- This is the difference between the total accumulation and the total ablation during 1 year
- In termperate glaciers, there is a negative balance in summer when ablation exceeds accumulation,and the reverse in winter
- If the summer and winter budgets are equal, the glacier appears to be stationary
- If supply begins to exceed the losses, the snout moves down the valley
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