Yr10 Glacial Landscapes

Question 1

What is a glacier?

Answer 1

A mass of ice that moves slowly downhill found in cold regions

Question 2

What are the 3 layers of a glacier?

Answer 2

Fresh snow at top
Old snow (granular and firm ice)
Glacial ice

Question 3

What are the 2 zones of a glacier?

Answer 3

• Accumulation zone (more snow added to the glacier)
• Ablation zone (where snow melts)

Question 4

Define ice age

Answer 4

A period of long tern cooling of earth’s atmosphere, resulting in an expansion of ice sheets and glaciers

Question 5

What are the cooler and warmer periods within an ice age called?

Answer 5

Cooler periods: glacials
Warmer periods: interglacials

Question 6

When was the most recent ice age and what was it called?

Answer 6

The pleistocene, 2 million years ago

Question 7

What are the 2 types of erosion carried out by glaciers?

Answer 7

Abrasion and plucking

Question 8

How is abrasion carried out by glaciers?

Answer 8

Sandpaper effect of rocks frozen to base of glacier smooths surface

Scratches caused by large rocks are called striations

Question 9

How is plucking carried our by glaciers?

Answer 9

• meltwater beneath glacier freezes and bonds to rocks
• when glacier moves, loose rocks are plucked away, leaving a jagged surface

Question 10

What are the 3 main ways a glacier moves?

Answer 10

• basal slip
• rotational slip
• Internal deformation

Question 11

How does a basal slip work?

Answer 11

Meltwater acts as a lubricant to glacier, allowing it to move downhill.
Can be quite sudden and occurs more often during summer

Question 12

How does a does a rotational slip work in glaciers?

Answer 12

Ice moves along curved surface to enlarge and develop hollows

Question 13

How does internal deformation work on a glacier?

Answer 13

• weight of ice and influence of gravity causes individual ice crystals to change shape in a plastic like way
• causes glacier to slowly move downhill

Question 14

What are corries and where are they found?

Answer 14

A deep depression found in the upper course of a glacier
- often have a steep back wall and usually a lake called a tarn
- usually have a raised lip at front
- sometimes referred to as cirque of cwm

Question 15

How are corries formed?

Answer 15

• snow accumulates in a hollow and is compressed into ice (slope is usually north facing)
• glacier get larger and starts to move
• plucking steepens back wall and abrasion + rotational slips deepens hollow
• rate of erosion at front of glacier lower due to thinner ice
• After melting, corrie is created, with scree slope at back that still freeze-thaws in winter

Question 16

What are arêtes and how do they form?

Answer 16

• a knife edge ridge with steep drop on either side
• form when erosion in 2 back to back corries causes land between them to narrow

Question 17

What are pyramidal peaks and how do they form?

Answer 17

• sharp peaks formed when 3 or more corries develop on all sides of a mountain
• ass corries erode towards each other, arêtes are formed
• they then combine to make a pyramidal peak

Question 18

What are hanging valleys and how are they formed?

Answer 18

• a tributary valley that is higher than the main valley of the glacier
• formed when a smaller tributary glacier flows from valley sides towards main glacial valley
• as glaciers flow through the rock on valley sides, they erode smaller tributaries onto the sides, leaving ‘hanging valleys’

Question 19

What are truncated spurs and how do they form?

Answer 19

• blunt ended sloping ridges which descends from thr flank of the valley
• formed by glaciers bulldozing any obstacles in glacial Valley, including interlocking spurs, leaving them with blunt edges

Question 20

What are ribbon lakes and how do they form?

Answer 20

• a long narrow lake in a glacial trough
• formed after glacier melts in an area of softer rock where glacier has eroded deeper. Meltwater sits in this depression, leaving ribbon lake

Question 21

What is a glacial trough and how does it form?

Answer 21

• before glaciation, a river valley is v shaped
• during Glaciation, rock in the valley sides is removed through plucking and abrasion
• results in a ‘u’ shaped glacial trough with very steep sides and straight wide valley sides

Question 22

What are moraines?

Answer 22

Piles of deposited rock by a glacier

Question 23

What are the 5 main types of moraine?

Answer 23

• ground
• lateral
• medial
• terminal
• recessional

Question 24

What are ground moraines?

Answer 24

Material dragged under glacier which is left behind when glacier melts

Question 25

What are lateral moraines?

Answer 25

As glacier moves down, scrapes down sides and makes it steeper, forms due to mass movement. Made of scree

Question 26

What are medial moraines?

Answer 26

Where 2 glaciers merge, and lateral moraines come together to form medial moraine.
Leaves a ridge in the middle after melting

Question 27

What are terminal moraines?

Answer 27

Material deposited at snout of glacier. Big build up

Question 28

What are recessional moraines?

Answer 28

Where glacier retreats in summer and moves slightly forward in summer leading to multiple lines of ridges, multiple terminal moraines

Question 29

What are drumlins?

Answer 29

• small egg shaped hills found on floor of glacial trough
• steep side is the stoss, shallow side is the lee
• elongated features that can reach up to 1km in length and over 500m in width, up to 50m on height
• a cluster of drumlins is a swarm

Question 30

How are drumlins formed?

Answer 30

• when glacier melts, a moraine is formed around an obstacle, as material builds up around it
• steep edge faces upstream and shallow edge goes downstream where ice flows over it

Question 31

Economic opportunities in glaciated regions of the UK?

Answer 31

• tourism
• grazing in uplands
• crops in fertile trough
• forestry
• quarrying

Question 32

What is a conflict matrix?

Answer 32

Used to identify where strongest conflicts between different groups occur