Glaciated landscapes Flashcards
What are the inputs of energy into glaciated systems?
Kinetic, potential or thermal energy
Name the throughputs of a glaciated system
- Stores (such as ice, water and debris)
- Transfers (such as moving ice, flowing water and movement of debris downslope due to gravity)
Explain how negative feedback is linked to a dynamic equilibrium.
Negative feedback means a system is restored back to its equilibrium. For example, mass is lost from a glacier by ablation and sublimation but further inputs of snow and ice add mass and restore the equilibrium.
Explain how seasons affect the glacial budget.
In summer, there are higher temperatures so this will increase rates of ablation over accumulation. The equilibrium line will move up the glacier. In winter, when temperatures are lower, there will be an increase in accumulation over the amount of ablation and the equilibrium line will move down the glacier towards the snout.
How does geology influence glaciated landscapes?
It affects the impact of weathering, erosion and mass movement processes. Structure, permeability and and also affect weathering and geomorphic processes.
How does aspect affect a glacial budget?
An aspect facing the sun will lead to more melting and a negative budget. An aspect facing away from the sun will mean less melting and a positive budget.
How is temperature linked to latitude and altitude?
An increase in latitude results in a decrease in temperature. An increase in altitude also results in a decrease in temperature.
Creep
Slow downward movement of loose rock and soil down a gentle slope.
Bed deformation
Movement of soft sediment of weak rock beneath a glacier. It is more effective beneath temperate glaciers as the underlying sediment and rock is saturated with water.
Intergranular flow
Where individual ice crystals move relative to each other.
Laminar flow
Where individual ice crystals move along layers within the glacier.
Explain the process of diagenesis.
The creation of glacier ice over a period of 30 to 1000 years. Snow that has survived a summer’s melt (firn) becomes further compacted by snowfall year on year until its density increases and air is expelled.
State three features of warm-based glaciers and three features of cold-based glaciers.
Warm-based glaciers
- Occur in temperate areas.
- They are small, with summer melts.
- Lubrication means more movement and more erosion, transportation and deposition.
Cold-based glaciers
- Occur in polar areas.
- Compose large glaciers and vast ice sheets.
- All ice in cold-based glaciers is below melting point, meaning slower movement, and the glacier is often frozen to the bed, resulting in less erosion, transportation and deposition.
What factors influence the movement of a glacier?
Gravity, gradient, ice thickness, internal ice temperatures and the glacial budget.
Which types of weathering processes are more significant in glaciated landscapes?
- Freeze-thaw: if temperatures are fluctuating above and below 0C.
- Pressure release: if glaciers or ice sheets are melting.
