Glacial Systems & Processes

Question 1

What is accumulation?

Answer 1

The addition of mass (precipitation, usually snow) to the glacier.

Question 2

Where does accumulation mainly occur?

Answer 2

Mainly occurs at higher altitudes at the source of the glacier.

Question 3

What is ablation?

Answer 3

The loss of mass from the glacier.

Question 4

What processes are included in ablation?

Answer 4

This includes meltwater, avalanches, sublimation, evaporation, and other processes.

Question 5

What is the glacial budget?

Answer 5

The mass balance of a glacier, i.e. the difference between accumulation and ablation.

Question 6

What does a positive glacial budget show?

Answer 6

Accumulation exceeds ablation, so the glacier is advancing.

Question 7

What does a negative glacial budget show?

Answer 7

Ablation exceeds acumulation, so the glacier is retreating.

Question 8

How do glacial budgets fluctuate yearly?

Answer 8

With more ablation in the summer months and more accumulation in winter months.

Question 9

What are glaciers in terms of systems?

Answer 9

Glaciers are natural systems, meaning there are specific interactions within their development and sustaining that allow glaciers to work.

Question 10

What happens in a natural system?

Answer 10

Something enters the system which allows for processes to occur, eventually leading to something leaving the system.

Question 11

What is an open system?

Answer 11

In an open system, there are inputs from outside the system’s set area.

Question 12

What is a closed system?

Answer 12

In a closed system, all of the inputs and processes occur within the system’s set area.

Question 13

What are inputs in a glacier system?

Answer 13

Additions to the glacier (accumulation).

Question 14

Give examples of inputs to a glacier.

Answer 14

Precipitation such as snow or hail and avalanches from other areas entering the system.

Question 15

What else can be an input to a glacier system?

Answer 15

Debris that has been eroded can also fall into a glacier’s system and consequently can be transported and deposited elsewhere.

Question 16

What are outputs in a glacier system?

Answer 16

Things that leave the glacier system, usually in the form of meltwater.

Question 17

What processes are outputs?

Answer 17

All ablation processes are outputs.

Question 18

What is calving?

Answer 18

A common output in which large pieces of glacier break off at the snout (the end).

Question 19

What determines glacial energy?

Answer 19

Glaciers all have varying amounts of energy dependent on their mass, their environment, their composition and other factors.

Question 20

What is an example of increased glacial energy?

Answer 20

A glacier with more meltwater underneath it would move faster, giving it more energy.

Question 21

What form is glacial energy usually in?

Answer 21

Kinetic energy as the glacier moves.

Question 22

What allows the glacier to have energy?

Answer 22

Gravity allows the glacier to have energy, as it forces the glacier downhill.

Question 23

What are stores in a glacier?

Answer 23

Stores are the mass that glaciers hold.

Question 24

What are the main stores in a glacier?

Answer 24

The majority of stores within the glacier are ice, but sediment from erosion and meltwater lakes/channels also contribute.

Question 25

What are the three types of glacial stores?

Answer 25

Subglacial (underneath the glacier), englacial (within the glacier), and supraglacial (on top of the glacier).

Question 26

What are flows in a glacier?

Answer 26

Flows occur in glaciers through the transfer of mass or energy.

Question 27

What do flows include?

Answer 27

There are flows in mass and energy from ice on the glacier to meltwater leaving the glacier.

Question 28

Give an example of a flow movement in a glacier?

Answer 28

Compressional flow.

Question 29

What does equilibrium refer to?

Answer 29

A state of balance.

Question 30

When is equilibrium dynamic?

Answer 30

When the processes causing the balance are continual (always occurring).

Question 31

When is a glacier in dynamic equilibrium?

Answer 31

If the amount of inputs and outputs are the same, the mass of the glacier does not change annually.

Question 32

What is the equilibrium line?

Answer 32

The area where mass gain = mass loss on a glacier.

Question 33

What is a feedback loop?

Answer 33

A type of chain reaction, where one process leads to another process, leading to another process, and so on.

Question 34

What are the two types of feedback loops?

Answer 34

Positive and negative.

Question 35

What happens in positive feedback?

Answer 35

A process occurs which causes another process, creating a chain reaction that heightens the first process.

Question 36

What is an example of a positive feedback loop?

Answer 36

Temperatures rise which causes permafrost to melt. This causes CO2 to be released which enhances the greenhouse effect. This leads to termperatures to rise further.

Question 37

What happens in negative feedback?

Answer 37

The process is counteracted by an opposing process, causing the effects to cancel each other out and nothing to change.

Question 38

What is an example of a negative feedback loop?

Answer 38

Temperatures rise, which causes permafrost to melt, more plants take in CO2, the greenhouse effect lessens and this causes temperatures to fall.