2.A6 The glacier landform system

Question 1

Glaciers alter landscapes from many different processes -

Answer 1

Erosion, entrainment, transport and deposition

Question 1

Glacier erosion in altering glacier landscapes -

Answer 1

Erosion - removal of rock material by ice and meltwater main ones are abrasion, plucking and meltwater erosion.

Question 2

Abrasion -

Answer 2

Abrasion used individual stones which erode the bedrock of the glacier which leads to micro features such as striations it is known to polish the underlying rocks in a kind of ‘sandpaper’ action.

Question 3

Plucking -

Answer 3

Often referred to as glacier quarrying. Can have two initial stages where it begins of widening the joints in the rock and then subsequent entrainment of loose material. The idea of plucking is the process is very dependant on pre-existing joints and the rock types. Where ice masses pull away masses of rock.

Question 4

Meltwater erosion -

Answer 4

Can be mechanical (similar to fluvial erosion but the water is under hydrostatic pressure. Whereby the meltwater can dissolve away minerals and solutes of little debris and can be carried away especially in limestone rocks (prime GCSE rivers knowledge)

Question 5

Entrainment inolvement in and out of the glacier -

Answer 5

Entrainment is the inclusion of of debris in, above or below the glacier.

Question 6

Supraglacial -

Answer 6

Debris is transported on the surface of the glacier (above). Can be material falling from hillsides picked up on the top or even volcanic ash (common on Icelandic glaciers)

Question 7

Englacial -

Answer 7

Debris is transported inside the glacier. Where material has moved or made its way down vertically through the ice sheet or glacier.

Question 8

Subglacial -

Answer 8

Debris transported below the glacier. This includes material that has been eroded from the glacier bed and valley walls and frozen to the base from the subglacial streams.

Question 9

Transportation can be of the three process within or out of the glacier -

Answer 9

Subglacial, Englacial or Supraglacial.

Question 10

Deposition -

Answer 10

When material is released from the ice at the margin or base of the glacier. This may occur directly on the ground or may be released into the meltwater. Can occur from melting or sublimation of the ice. Can occur by friction at the bedrock.

Question 11

Landform scales can either be -

Answer 11

Meso-scale, Macro-scale, Micro-scale.

Question 12

Examples of Meso-scale landforms -

Answer 12

Crag and tail, roches moutennees, drumlins, kames, eskers kettleholes.

Question 13

Examples of Micro-scale landforms -

Answer 13

Features such as striations, glacial grooves, chatter marks, erratics.

Question 14

Examples of Macro-scale landforms -

Answer 14

Ice sheet, eroded Knock and Lochan, Cirques, Aretes, pyramidal peaks, glacial troughs ribbon lakes. Terminal moraines.

Question 15

Periglacial areas -

Answer 15

Have no ice cover but were underlain by permafrost

Question 16

Proglacial areas -

Answer 16

Occur in the front of ice masses where meltwater deposition and wind action on glacially eroded sediments took place.

Question 17

Ice-marginal areas -

Answer 17

were at the edges of ice sheets and valley glaciers, where deposition of ice was dominant

Question 18

Subglacial areas -

Answer 18

Would have been covered by either warm or cold-based ice for thousands of years at a time and dominated by the action of erosion and erosional landforms.