How can glaciated landscapes be viewed as systems

Question 1

What is a system

Answer 1

a set of interrelated objects that are connected together

Question 2

What energy is available to glacial landscapes

Answer 2

Kinetic
Potential
Thermal

Question 3

Inputs of glacial systems

Answer 3

Kinetic energy (wind, moving ice)
Thermal energy (sun)
Potential energy (position of material on slopes)
Precipitation and snow

Question 4

Outputs of glacial systems

Answer 4

Glacial wind erosion
Evaporation
Sublimation and meltwater

Question 5

Processes in glacial systems

Answer 5

Stores (ice water, accumulation)
Flows (movement of ice + water, movement of debris)

Question 6

Glacial mass balance

Answer 6

Difference between accumulation and ablation in a one year period

Question 7

Firn line

Answer 7

Equilibrium line where ablation and accumulation are equal

Question 8

What is negative feedback

Question 9

What is positive feedback

Question 10

How do glacial systems show negative feedback

Answer 10

They have a dynamic equilibrium, in the event of the equilibrium being disturbed the system self regulates until balance is restored

Question 11

Annual budget

Answer 11

total ablation - total accumulation = annual budget

(+ figure means net accumulation)
(- figure means net ablation)

Question 12

Two things that may affect mass

Answer 12

• Seasonal changes
• Temporal changes

Question 13

How does climate influence glacial landscapes

Answer 13

• Wind can carry out erosion, transportation and deposition
• Precipitation is key to determine mass balance
• Temperature is key in determining mass balance and glacial movement

Question 14

What is geology

Answer 14

-Lithology
-Structure

Question 15

How does lithology influence glacial landscapes

Answer 15

-Lithology
-physical and chemical rock composition
-rocks like basalt have strong lithology so are resistant (likely to form structures like corries and arêtes)
- rocks like clay have weak lithology so erode easily

Question 16

How does structure influence glacial landscapes

Answer 16

Structure
- properties of rocks (e.g jointing, bedding, permeability)
-rocks like limestone have many joints so high water permeability

Question 17

How do latitude and altitude influence glacial landscapes

Question 18

How do relief and aspect influence glacial landscapes

Question 19

How does the formation of glacial ice influence glacial landscapes

Answer 19

• Glaciers form when temperatures are low enough that snow falls in one year remains the following year
• When snow falls the following year it compacts the previous years snow

Question 20

Firn

Answer 20

Snow that survives one summer

Question 21

Diagenesis

Answer 21

The layering and compacting process of snow year on year

Question 22

Ice sheets

Answer 22

• largest accumulations of ice
• more than 50,000km2
• only two ice sheets: Antarctica, Greenland

Question 23

Warm based glaciers

Answer 23

• high altitude
• steep relief
• basal temperatures above pressure melting point
• rapid movement
• found in the Alps and Rockies
• high accumulation and ablation
• high seasonal variation
• significant erosion
• lots of ice transported over firn line

Question 24

Cold based glaciers

Answer 24

• high latitude
• low relief
• basal temperatures below pressure melting point (frozen to bedrock)
• very slow movement rates (few m/yr)
  -found in Antarctica and Greenland
  -no large seasonal variation
  -limited erosion and deposition

Question 25

Basal sliding

Answer 25

• warm based glaciers move by basal sliding
• if basal temperatures are above pressure melting point a thin layer of meltwaters is under the glacier reducing friction

Question 26

Internal deformation

Answer 26

• cold based glaciers move by internal deformation
• “inter-granular flow” is where crystals re-orientate and move in relation to each other
• laminar flow is where there is movement of individual layers of annual accumulation
  -extending flow is wher

Question 27

Pressure melting point

Question 28

Intergranular flow

Answer 28

where crystals re-orientate and move in relation to each other

Question 29

Laminar flow

Answer 29

where there is movement of individual layers within the glacier, often layers of annual accumulation

Question 30

Extending flow

Answer 30

when the ice goes over a steep slope and is unable to deform quickly enough so cracks and forms creases

Question 31

Compressing flow

Answer 31

when gradient is reduced and the ice thickens pushing the slower moving leading ice

Question 32

Factors affecting glacial movement

Answer 32

• gravity
• gradient
• ice thickness (influences pressure
  melting point and basal temperatures)
• glacial budget (positive budget causes advance)