Glaciated Landscapes: Glacier Mass Balance And Equilibrium Flashcards
What is feedback?
An output in a system that causes changes to the systems inputs
What is negative and positive feedback?
Negative feedback reduces or reverses processes, positive feedback furthers change
What is glacier mass balance?
The difference between snow and ice accumulation and ablation in a glacier over one year
Where does the majority of input occur in a glacial system?
The upper areas, called the accumulation zone, where accumulation exceeds ablation
Where is the majority of output in a glacial system?
At lower levels, called the ablation zone, where ablation exceeds accumulation
What defines the equilibrium line of a glacial system?
The area that seperates the ablation and accumulation zones, where there is a balance between accumulation and ablation
How do you calculate the annual budget of a glacier?
Subtracting total ablation from the total accumulation
What happens when a glacier has a positive annual budget/glacier mass balance?
The glacier will gain ice and advance, moving the equilibrium line down-valley
What happens when a glacier has a negative annual budget/glacier mass balance?
The glacier will lose ice and retreat, moving the equilibrium line up-valley
What happens if accumulation equals ablation?
The glacier will be in equilibrium and won’t advance or retreat, but instead remain stationary
When does accumulation increase and ablation decrease?
The winter
When does accumulation decrease and ablation increase?
The summer
How can retreating glaciers appear to advance?
As the ice moves down-slope, however is losing ice overall
