What processes operate within glacial systems?

Question 1

what are some glacial inputs

Answer 1

precipitation
Avalanches
meltwater
rock debris

Question 2

what are the glacial stores/ processes? (General)

Answer 2

the moving glacier erodes transports and deposits rock debris

Question 3

what are the glacial outputs

Answer 3

meltwater
icebergs
water vapour
rock debris

Question 4

what is accumulation

Answer 4

the input of snow and ice into a glacier

Question 5

what processes cause accumulation

Answer 5

precipitation
wind deposits
avalanches

Question 6

what is ablation

Answer 6

the output of snow and ice from a glacier

Question 7

What are some ablation processes?

Answer 7

melting
ice berg calving
sublimation
evaporation

Question 8

what is iceberg calving

Answer 8

when chunks of ice break off at the terminus, or end. of the glacier

Question 9

what can cause accumulation rate to vary

Answer 9

high levels of inputs
low average temperatures
low levels of insolation
low wind speed

Question 9

where are the highest rates of ablation

Answer 9

higher altitudes
on slopes with a poleward aspect

Question 10

where/ what is the accumulation zone?

Answer 10

the uppermost section where there is greater accumulation than ablation

Question 11

where/ what is the ablation zone

Answer 11

lower part of the glacier when the rate of ablation is higher then accumulation

Question 12

what is the equilibrium line

Answer 12

the boundary between zones where rate of accumulation and ablation are equal

Question 13

how is glacial mass balance calculated

Answer 13

subtracting total ablation away from total accumulation for the year

Question 14

what is positive mass balance

Answer 14

when total accumulation exceeds ablation

Question 15

what is negative mass balance

Answer 15

when ablation is higher than accumulation

Question 16

how does the glacier move in positive mass balance

Answer 16

the glacier will advance as there is greater ice content

Question 17

how will the glacier act when in negative mass balance

Answer 17

it will retreat as the input into the glacier is reduced

Question 18

what will happen to the snout when in dynamic equilibrium

Answer 18

the glacier snout will remain stationary

Question 19

what are feedback loops

Answer 19

deviations in in puts or outputs that move systems away from a balanced state

Question 20

what do negative feedback cycles act to do?

Answer 20

minimise the effect of the new input, in order to re-establish stability

Question 21

what is an example of a negative feedback loop

Answer 21

more snow in accumulation zone
increased ice volume, glacial advance
more ice volume in ablation zone
more ablation
overtime output of meltwater equals snow input
return to balance

Question 22

what do positive feedback loops do?

Answer 22

Amplify the initial change and might cause a shift in the system to a new state of equilibrium

Question 23

what is an example of a positive feedback loop (glacier)

Answer 23

positive mass balance
surface area increases
increased albedo
reduced air temperatures
increased accumulation
initiating positive feedback (continued advance)

Question 24

how fast does the Jakobshavn glacier moving

Answer 24

20 meters per day at its snout

Question 25

what affects glacial movement

Answer 25

temperature of ice if PMP is satisfied

Question 26

what happens to the melting point of ice with increased depth of a glacier

Answer 26

the temperature will be fractionally lowered due to the pressure of the overlying ice

Question 27

what does the meltwater do on temperate glaciers

Answer 27

acts as a lubricant between the rock and the ice allowing the glacier to move

Question 28

what is the process where meltwater acts as a lubricant for the ice

Answer 28

Basal slip

Question 29

what glacier does basal slip happen at

Answer 29

most temperate glaciers

Question 30

why cant PMP be satisfied in polar glaciers

Answer 30

Too cold to produce melt water

Question 31

what happens between the bedrock and a polar glacier

Answer 31

the ice is frozen to the bedrock movement only occurs by internal deformation

Question 32

what is internal deformation

Answer 32

gravity and the pressure of the ice in the accumulation zone cause ice crystals to slide over each other in a series of parallel planes in a 'crumpling deformation'

Question 33

what can internal deformation form

Answer 33

deep crevasses at the surface

Question 34

what factors control the rate of glacial movement

Answer 34

ice temperature rate of ablation ice thickness precipitation levels bedrock permeability ice and slope gradient

Question 35

how does ice temperature influence movement

Answer 35

colder ice moves more slowly as it does not deform as easily and stays stuck to the bedrock more

Question 36

how does rate of ablation affect movement

Answer 36

The more melt water there id the faster the movement as basal slippage increases

Question 37

how does ice thickness affect ice glacier movement

Answer 37

when the ice is 50m thick plastic flow begins. the grater the thickness the greater the pressure causing faster movement (more melt water)

Question 38

how does precipitation level affect glacial movement

Answer 38

higher snowfall leads to greater accumulation and faster movement

Question 39

how does bedrock permeability affect glacial movement

Answer 39

if the bedrock is permeable, then meltwater may be able to soak away slowing the glacier

Question 40

what is the process of water soaking into rocks

Answer 40

percolation

Question 41

will movement be slow or quick over clay

Answer 41

quick as clay is deformable

Question 42

how does ice and slope gradient affect movement

Answer 42

the steeper the slope the faster the movement due to gravity

Question 43

what type of glacier is Briksdalbreen

Answer 43

a temperate/ warm based glacier

Question 44

what ice cap feeds the Briksdalsbreen glacier

Answer 44

Jostedalsbreen ice cap

Question 45

what is the altitude range for the brikdalsbreen glacier

Answer 45

1910m to 350m

Question 46

what erosional processes take place in a glacial environment

Answer 46

frost shattering abrasion plucking fracture/traction dilation meltwater erosion

Question 47

What are the 3 areas in a glacier where material is transported

Answer 47

Sub-glacially En-glacially Supra-glacially

Question 48

Where does deposition occur in a glacier?

Answer 48

At the snout Where surrounding ice sublimates Friction against the base

Question 49

What is a relict glacial landscape

Answer 49

A area not currently glacially active but features fossilised glacial landforms due to past glacial activity

Question 50

What are macro-scale landforms? (definition)

Answer 50

Large scale landforms that have been created by a combination of glacial processes over time

Question 51

What is an example of a macro scale landform

Answer 51

Cirques Arêtes Pyramidal peaks Terminal moraines (Ice sheet eroded landscapes- all features combined)

Question 52

What are meso-scale landforms

Answer 52

Intermediate scale landforms that have been created mostly by erosion but can also be created by meltwater erosion

Question 53

What are some examples of meso-scale landforms

Answer 53

Roches moutonnes Drumlins Kames Eskers Kettle holes (fluvioglacial landform)

Question 54

What are micro-scale landforms? (Definition)

Answer 54

Small scale landforms in some cases quite small in size

Question 55

What are some examples of micro-scale landforms

Answer 55

Striations Chatter marks Erratics

Question 56

What are the 4 main glacial environments we need to know about?

Answer 56

Subglacial Ice marginal Proglacial Periglacial

Question 57

What is the subglacial environment

Answer 57

The environment beneath the glacier ice subject to immerse pressure from the overlying ice

Question 58

What is the ice marginal environment

Answer 58

Environment at the edge of the glacial ice where a combination of a glacial and fluvioglacial processes take place

Question 59

What is a proglacial environment

Answer 59

Located at the front of the glacier, ice cap or ice sheet dominated by fluvioglacial activity

Question 60

What is a Periglacial environment

Answer 60

Environment found near the glaciers dominated by freeze thaw activity but not dominated by moving ice

Question 61

What are past glacial landscapes useful for

Answer 61

Allows us to see exact position and extent of ice cover This process is called inversion modelling

Question 62

what processes of glacial erosion are there

Answer 62

plucking crushing abrasion fluvio-glacial erosion

Question 63

What is frost heave?

Answer 63

Physical weathering process involving the cyclic freezing and thawing of water in soil or rock Heave is the upward movement of the ground due to ice crystal/lenses in the soil