GL07 Glacial Mass Balances Flashcards
Mass Balance Diagram
Why are scientists concerned about the Thwaites Glacier?
Scientists are concerned about the Thwaites Glacier because it is one of the largest glaciers in the world and is melting rapidly. Its melting could potentially lead to a significant rise in global sea levels.
What is the definition of accumulation in a glacial landscape system?
Accumulation is the accretion of snow and ice onto a glacier. It occurs at high latitudes and altitudes where temperatures prevent melting.
What is the definition of ablation in a glacial landscape system?
Ablation is the loss of ice mass due to melting and sublimation (amount of ice mass loss due to sublimation is relatively minor compared to melting).
What is the definition of mass balance in a glacial landscape system?
The annual mass balance (budget) of a glacier is the difference between accumulation and ablation over one year.
What is the accumulation zone in a glacial landscape system?
The accumulation zone is the top section of a glacier where there is the least melting, so this part has a positive mass balance.
What is the ablation zone in a glacial landscape system?
The ablation zone is the lower section of a glacier that has the least snowfall and the most melting, so it has a negative mass balance.
What is the equilibrium line in a glacial landscape system?
The equilibrium line is the line between the two zones where accumulation equals ablation.
What is dynamic equilibrium in a glacial landscape system?
Dynamic equilibrium is the idea of a system adjusting to bring itself back to equilibrium if either the inputs or outputs change and equilibrium is disturbed. It does this through negative feedback loops to counteract the change.
What are the dominant processes in the upper parts of a glacial landscape system?
In the upper parts of the glacial landscape system, accumulation happens at a much higher rate.
What are the dominant processes in the lower parts of a glacial landscape system?
In the lower areas of the glacial landscape system, ablation is more important.
What is the snout of a glacier?
The snout of a glacier is the very end part.
Where does most snowfall on a glacier occur and what is the result?
Most snow falls on the top section of a glacier where there is the least melting, resulting in a positive mass balance (inputs are greater than outputs). This section is known as the accumulation zone.
What does the position of the equilibrium line indicate in terms of glacier mass?
Recording the position of the equilibrium line can indicate the long-term rate of increase or decrease in glacier mass, as it moves depending on the seasons and changes in ablation and accumulation throughout the year.
What is the state of equilibrium for a glacier?
Glaciers theoretically exist in a state of equilibrium when the inputs are perfectly balanced with outputs.
