Glaciated landscapes Glossary Flashcards Preview

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Flashcards in Glaciated landscapes Glossary Deck (77)
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1
Q

Glacier

A

Compressed snow. Ranging from 1km to the scale of Antarctica

2
Q

Glaciated landscape

A

A landscape that has features to form a glacier. These can be active or a relic landscape

3
Q

Ablation

A

Loss of mass- ice

4
Q

Accumulation

A

More mass- ice

5
Q

Zone of accumulation

A

Greater amounts of accumulation than ablation

6
Q

Zone of ablation

A

Greater amounts of ablation than accumulation

7
Q

Equilibrium line

A

Separates the 2 zones of accumulation and ablation

8
Q

Glacial mass balance

A

Difference between the amount of snow and ice accumulation and the amount of ablation occurring in a glacier over a year

9
Q

System

A

Set of interrelated elements comprising of components (stores) and processes (links) that are connected together

10
Q

Pressure melting point

A

Refers to the temperature at which ice is at the verge of melting

11
Q

Basal sliding

A

Sliding of glacier over bedrock

12
Q

Regelation (or creep)

A

The base of the ice meets a rock outcrop on the valley floor the ice may flow around it

13
Q

Intergranular slip

A

Weight of ice can result in ice crystals changing shape due to compaction. Ice crystals become flattened and slide over each other

14
Q

Laminar flow

A

Ice flow in layers

15
Q

Rigid zone

A

Upper zone of thew glacier where the ice is brittle and breaks

16
Q

Plastic zone

A

Lower zone of the glacier where the under the pressure the ice deforms

17
Q

Freeze thaw

A

Process of weathering caused by water, confined in rock joints, expanding as it freezes

18
Q

Plucking

A

Rocks and stones become frozen to the base or sides of glacier and are plucked from the ground

19
Q

Abrasion

A

Process of erosion whereby stones and rocks become embedded in the base and sides of the glacier

20
Q

Opened system

A

Matter and energy can be transferred

21
Q

Corrie

A

Armchair shaped hollow found on upland hills or mountains

22
Q

Geomorphic processes

A

Natural mechanisms of weathering, mass movement, erosion, transportation and deposition

23
Q

Weathering

A

Breakdown of rocks

24
Q

Erosion

A

Wearing away or removal of rock

25
Q

Physical weathering

A

Breakdown of rock by physical processes

26
Q

Chemical weathering

A

The decay of rocks as a result of chemical weathering

27
Q

Biological weathering

A

May consist of physical actions such as growth of plant roots

28
Q

Oxidation

A

Minerals in rocks react with oxygen, either in the air or in water.

29
Q

Frost shattering

A

Extremely low temperatures water trapped in rock pores freezes and expands

30
Q

Solution

A

Mineral dissolves in water

31
Q

Hydration

A

Water molecules added to rock minerals create new minerals of a larger volume

32
Q

Tree roots

A

Tree roots grows into cracks or joints in rocks and exert outward pressure

33
Q

Carbonation

A

Rainwater combines with dissolved carbon dioxide from the atmosphere to produce a weak carbonic acid

34
Q

Organic acids

A

Produced during decomposition of plant and animal litter

35
Q

Hydrolysis

A

Chemical reaction between rock minerals and water

36
Q

Pressure release

A

The weight of the overlying ice in a glacier is lost due to melting

37
Q

Supraglacial debris

A

Carried on the surface of a glacier. Comes forms weathering and mass movement

38
Q

Englacial debris

A

Carried within the glacier. Comes from surface debris which has fallen down a crevasse

39
Q

Subglacial debris

A

Transported at the base of the debris. Comes mainly from plucking and abrasion

40
Q

Glacial till

A

Material deposited directly by the ice

41
Q

Glacio-fluvial material

A

Deposited by meltwater

42
Q

Lodgement till

A

Material deposited at the base of advancing glaciers due to basal melting

43
Q

Ablation till

A

Material deposited as the ice melts away from retreating glaciers

44
Q

Angular or sub-angular

A

In shape

45
Q

Unsorted material

A

Large fragments and small debris

46
Q

Unstratified

A

No sign of layering

47
Q

No orientation

A

Rock fragments are no aligned in the same direction

48
Q

Ribbon lake

A

A long narrow, finger-shaped lake, usually found in a glacial trough

49
Q

Rock Bar

A

A rid or outcrop of rock either side of rock basin variations

50
Q

Rock Basin

A

An over deepened section of the floor of the glacial trough

51
Q

Rock Flour

A

Very fine material produced by abrasion

52
Q

Rochee Moutonnee

A

A mass of resistant rock on the floor of a glacial trough which is smooth and rounded on the stoss (or up the valley side)- often with striation marks showing direction of ice movement

53
Q

Striation

A

Scratches or gouges cut into the bedorck by glacial abrasion

54
Q

Till

A

material deposited directly by the ice

55
Q

Pyramidal peak

A

an angular, sharply pointed mountain top sometimes described as a horn shaped summit

56
Q

Nivation

A

is a glacial process that is not easily classified as erosion or weathering

57
Q

Arete

A

a narrow, steep sided ridge often called a knife edge ridge

58
Q

Corrie

A

Is an arm-chair shaped hollow found on the upland hills or mountain sides. They have a steep back wall, an over-deepened basin and a rock lip at the front

59
Q

Hanging valley

A

A smaller tributary valley to the side of the main glacial trough, left ‘hanging’ above the main u-shaped val;ley. A waterfall can be seen

60
Q

Mass movement

A

Is the down slope transportation of material under gravity

61
Q

Glacial trough

A

A u-shaped valley with steep, straight sides and a flat rounded bottom, carved out from a glacier

62
Q

Geomorphic processes

A

natural processes relating to the formation and shaping of landforms and landscapes

63
Q

Drumlin

A

A mound of glacial debris that has been streamlined into an elongated hill

64
Q

End Moraine

A

The collective term for the three types of moraine ridge that can be formed from deposition at the snout

65
Q

Erratic

A

An individual piece of rock, varying from a small pebble to a large boulder which is composed of different geology from the area in which it has been deposited

66
Q

Lateral Moraine

A

A ridge of till running along the glacial valley

67
Q

Medial Moraine

A

A ridge of till running along the middle of a glacial valley

68
Q

Moraine

A

Moraine is used to refer to an accumulation of a glacial till to form a ridge

69
Q

Push moraine

A

Till which has been shunted up into mound. Therfore the long axis of the individual stones may be orientated upwards from their original horizontal position

70
Q

Recessional Moraine

A

A series of ridges running transversely across glacial troughs and which are broadly parallel to each other and to the end moraine. They are found further up the valley than the terminal moraine

71
Q

Terminal moraine

A

A ridge of till extending across a glacial trough.

72
Q

Till sheets

A

Formed when a large mass of un-stratified drift is deposited at the end of a period of ice sheet advance, which smooths the underlying surface

73
Q

Hummocky moraines

A

Moulds of glacial till left by retreating corrie glacier

74
Q

The skiddaw Group

A

Mainly slates and not resistant to weathering and erosion

75
Q

The Windermere Group

A

Mainly sedimentary rocks which are least resistant to weathering and erosion

76
Q

The Borrowdale Volcanic

A

Igneous rocks which are resistant rocks

77
Q

Ice sheet

A

Large accumulations of ice which bury the landscape beneath. They extend for more than 50,000

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