Glaciation Unit

Question 1

What is glaciation?

Answer 1

a process by which glaciers form and spread

Question 2

How are glaciers formed?

Answer 2

When snow remains in the same area year-round, where enough snow accumulates to transform into ice.

Question 3

Glacial Erosion

Answer 3

plucking, abrasion and freeze thaw

Question 4

plucking

Answer 4

the process by which pieces of bedrock are lifted out of place by a glacier

Question 5

Abrasion

Answer 5

The grinding away of rock by other rock particles carried in water, ice, or wind

Question 6

Freeze- Thaw

Answer 6

Breaks down rock when water gets into rock joints or cracks and then freezes and expands, breaking the rock.

Question 7

Formation of a Corrie

Answer 7

Snow collects in a hollow high up a mountain on a north facing slope.

Over time the snow compacts to ice because of the weight, to form a glacier.

The glacier starts to move downhill due to gravity and subglacial meltwater.

Stones trapped in the ice scraped against the base of the hollow eroding it (abrasion) making the hollow deeper.

The glacier freezes on to stones and plucks them out as it moves downhill (plucking) which steepens the back wall of the hollow.

After glaciation melted ice stayed in the hollow forming tarns which were trapped behind the corrie’s lip.

Question 8

Formation of an Arete

Answer 8

Snow collects in a hollow high up a mountain on a north facing slope.

Over time the snow compacts to ice because of the weight, to form a glacier.

The glacier starts to move downhill due to gravity and subglacial meltwater.

Stones trapped in the ice scraped against the base of the hollow eroding it (abrasion) making the hollow deeper.

The glacier freezes on to stones and plucks them out as it moves downhill (plucking) which steepens the back wall of the hollow.

Where two or more corries formed back to back or side by side, the rock between them was plucked away to form a narrow ridge.

Question 9

Formation of a Pyramidal Peak

Answer 9

3 or more Corrie develop around a hill, back walls retreat to meet at a central point, steepened to form pyramidal peak, weathering may sharpen shape

Question 10

Formation of a U-Shaped Valley

Answer 10

A v-shaped valley fills with glacial ice. The glacier widens, deepens and straightens the valley through abrasion and plucking. Interlocking spurs are cut off to create truncated spurs.It is now a U-shaped valley, the original river is now called a misfit stream

Question 11

Formation of Hanging Valley

Answer 11

A large glacier fills the main valley and a tributary glacier ( which is high up) joins it. The glacier melts leaving a ‘u’ shaped valley. The water comes from the mountains or a tarn which is further up.

Question 12

Formation of a truncated spur

Answer 12

Is formed when the slope of a hill is eroded by a glacier eg. by abrasion (stones trapped in the glacier, scraping against the spur eroding it).

As the ice moves down the valley it erodes the sides of the hills.

The ice at the edge of the glacier freezes on to the rock and pucks it away which helps to remove the spur.

When the ice melts, the slope is left as the steep side of a U-shaped valley and may have crags or cliffs where erosion was greatest.

Question 13

Definition of glaciatiom

Answer 13

A glacier is a large mass of ice often shaped like a river that moves due to its own weight.

Question 14

Hill Sheep Farming

Answer 14

Sheep are sure footed and can live on the steep land. The land can’t be used for any other type of farming. The soil is infertile and so crops can’t grow well.

Question 15

Forestry

Answer 15

The low land is too valuable so the uplands are used to plant trees. One of the most profitable industries. Does not require fertile soil.

Question 16

Hydro-electric Power Stations

Answer 16

Using water to create electricity. High rainfall in the mountains. Corries are used to store water.

Question 17

Recreation + Tourism

Answer 17

Uplands are popular with tourists due to the beautiful scenery. Hill walking and mountaineering are popular. Water sports and skiing. Visiting historical sites.

Question 18

Two other uses of glaciated uplands are….

Answer 18

Renewable Energy and water supply and storage.

Question 19

How to identify a corrie?

Answer 19

Look out for horseshoe shaped contour lines on the map (to remind yourself, look at the back of your thumb!) They might have a corrie lake or tarn in them (but not always) and may be named as a corrie.

Question 20

How to identify an arete?

Answer 20

Contour lines will be closely packed together either side of the arete, as the sides of the aretes are steep. The top surfaces of the aretes are often rocky; therefore, you may also find that the symbol to show loose bare rocks may follow the top surface of the arete.

Question 21

How to identify a Pyramidal peak?

Answer 21

Pyramidal peaka have a sharp summit and steep slopes on at least three sides. A pyramidal peak may form where three or more corries erode back so far that they produce aretes with a pyramidal peak in between. They can often be seen as triangular on the map with a point summit.

Question 22

How to identify a hanging valley>

Answer 22

A hanging valley is a smaller side valley left ‘hanging’ above the main u-shaped valley, the contour lines will look like a normal u-shaped valley, but the contours will suddenly stop and will be cut by the steep sides of the main valley.

Question 23

How to identify a truncated spur?

Answer 23

Truncated spurs often have almost right-angled contours lines, by the hanging valleys.

Question 24

How to identify a u-shaped valley?

Answer 24

U-shaped valleys have steep sides and a wide flat floor. They are usually straight and deep. The valley sides will have closely packed contour lines, to show the steep valley sides, the valley floor in contrast will have very few contours, as it is wide and flat.

Question 25

How to identify a ribbon-lake?

Answer 25

A ribbon lake is a large, narrow lake occupying a u-shaped valley. It forms in a hollow when a glacier has more deeply eroded less resistant rock or it may fill up a valley behind a wall of moraine across the valley.

Question 26

How to identify a misfit stream?

Answer 26

Misfit streams meander through the flat, wide u-shaped floor. They did not erode the valley, as they formed in the valley after glaciation has carved out the U-shaped valley.