1a. Glaciated landscapes as systems Flashcards
Inputs
- snow
- solar radiation
- kinetic energy
- material from weathering
Outputs
- meltwater (from sublimation)
- glacial/wind erosion
- evaporation / sublimation
Processes (which consist of stores)
All forms of glacial movement
- deposition
- glacial & wind erosion
- movement downslope
Stores
- ice
- meltwater
- deposits of material
What is an example of negative feedback in a glacial system?
When the glacier is no longer at equilibrium so the system produces its own response to the disturbances (dynamic equilibrium)
What is a landform?
- Individual feature
- created by glacial erosion, deposition, fluvial-glacial activity or activity within periglacial
What is a landscape?
Made up of landforms
When was the Pleistocene period?
2.6 million years ago to 12,000 years ago
What are glacials and interglacials during the Pleistocene period?
- Glacials - colder periods (more ice cover)
- Inter-glacials - warmer periods (less ice cover)
Ablation
reducing of glacier by melting, sublimation or calving
Accumulation
addition to glacier by snowfall
Calving
detachment of icebergs from the glacier into water
Glacial retreat
shrinking of the glacier (due to negative mass balance)
Glacial advance
forward movement of glacier (due to positive mass balance)
What is glacier mass balance/glacial budget?
Difference between the total accumulation and ablation that occurs over a 1 year period
What is the accumulation zone?
- where majority of inputs occur in upper part of glacier
- where accumulation exceeds ablation
What is the ablation zone?
- where majority of outputs occur in lower part of glacier
- where ablation exceeds accumulation
What is the equilibrium line?
The point at which there is a balance of accumulation and ablation between the two zones
How do you calculate the annual budget of a glacier?
total accumulation - total ablation
+ figure = glacial advance, equilibrium line will move down the valley
- figure = glacial retreats up valley
What happens when input > output?
glacier advances, moves down valley
What happens when input < output?
glacier retreats, moves up valley
Glacial budget graph
-
