Glaciation

Question 1

When was the last ice age

Answer 1

18,000 years ago

Question 2

How much of the land did the last ice age cover

Answer 2

30% of the world

Question 3

What is an ice age?

Answer 3

A period of time when thick ice sheets cover vast areas of land and the global temperature is below 0°C

Question 4

What is a Galcier

Answer 4

A large body of ice that moves slowly down a slope or over a wide area of land

Question 5

What is an example of a glacier in Europe

Answer 5

Mer de Glace in French alps

Question 6

What three processes of glaciation that effects the landscape

Answer 6

Erosion
Transportation
Deposition

Question 7

How do glaciers form?

Answer 7

1. They form in cold places where lots of snow falls but not all of it melts
2. The snowfall forms many layers of snow, where the bottom layers get compressed into ice as air is pushed out
3. This compression of snow into ice creates a glacier.

Question 8

Whats the difference between an ice sheet and a glacier?

Answer 8

Ice sheets are masses of ice which cover large areas of a continent
Whilst glaciers occupy mountain valleys (called valley glaciers)

Question 9

What countries were covered in ice during the last ice age

Answer 9

Switzerland
Ireland
Norway
Sweden
Finland
Denmark

Question 10

What is an interglacial

Answer 10

A period of time when there aren’t any large ice sheets, unlike ice ages

Question 11

What is the current coverage of ice on the earths surface (%)

Answer 11

10% of the earths surface is covered in ice, mainly in Antarctica and Greenland and as well in high altitudes

Question 12

What is an input of a glacier?

Answer 12

An input can come from an avalanche but it is mainly from snow fall (precipitation)

Question 13

What is an output?

Answer 13

Meltwater is the main output from a glacier, along with evaporation.

Question 14

What is accumulation

Answer 14

It is when there is more inputs than outputs (inputs>outputs=accumulation)

Question 15

What is ablation

Answer 15

When there are more outputs than inputs (outputs>inputs=ablation)
Ablation usually occurs in summer at lower altitudes and this can cause the glacier to retreat.

Question 16

What is accumulation AND ablation

Answer 16

It is when inputs and outputs are equal and balanced

Question 17

What are the three main processes of a glacier

Answer 17

Frost shattering
Abrasion
Plucking

Question 18

What is frost shattering?

Answer 18

It describes the action of glacier meltwater on joints, cracks and hollows in rock.
- Water enters a crack during the day
- At night the temp. drops and the water freezes and expands, causing the crack to widen

Question 19

What is Abrasion

Answer 19

The moraine frozen into the glacier acts as sandpaper against valley sides and base.
(like corrosion but on a larger scale)

Question 20

What is plucking

Answer 20

When water freezes onto rock on the valley base.
The glacier pulls the rock from the valley base.
Plucking mainly occurs when the rock is well jointed

Question 21

What is a corrie?

Answer 21

It is when snow collects in a natural hollow on the side of a mountain. Over time the snow builds up, this extra weight compresses the snow underneath, turning it to ice

Question 22

How is a tarn formed?

Answer 22

1. Snow gathers in a hollow and turns to ice
2. Material from the base of the hollow is plucked out, making the hollow deeper through abrasion
3. Eventually the ice outgrows the hollow and goes down the slope due to gravity
4. When the ice melts it leaves a deepened hollow called a corrie.
5. When this corrie fills with water it becomes a lake, this is called a tarn.

Question 23

What is an Arête

Answer 23

A knife edged ridge formed between two corries.
When 2 corries form next to eachother and their adjacent walls are erroded backwards until they meet a narrow and pointed rock ridge is formed, this ridge is an Arête

Question 24

What is a pyramid peak?

Answer 24

When 3 or more corries are formed back to back

Question 25

What is a U-shaped valley also known as?

Answer 25

A glacial trough

Question 26

How is a U-shaped valley formed?

Answer 26

A glacier will move down a V-shaped valley created by a river, rocks trapped in the bottom of the ice will act like sandpaper a wear away at the valley through abrasion, the glacier will deepen, straighten and widen the valley through this abraision. After the ice melts there will be a U-shaped valley remaining.

Question 27

What is a misfit valley

Answer 27

A river that flows through the valley after an ice age. (This river couldnt have eroded the valley)

Question 28

What are between truncated spurs?

Answer 28

Hanging valleys are in between truncated spurs, they are places that have not been eroded as deeply as the main valley

Question 29

What landforms are created by glacial deposition?

Answer 29

- Moraines - Drumlins - Erratics

Question 30

What type of landform is a moraine?

Answer 30

It is created when a glacier deposits the material (till) that it has been transporting. Its made up of unsorted and angular rocks.

Question 31

Where is a Terminal Moraine found?

Answer 31

A terminal moraine is found at the furthest point of a glacier (end of a glacier)

Question 32

Where is a lateral moraine found?

Answer 32

A lateral moraine is found along the sides of a glacier

Question 33

Where is a medial moraine found?

Answer 33

A medial moraine is found at the junction between two glaciers.

Question 34

Where is a ground moraine found?

Answer 34

A ground moraine is a diagnosed pile of rocks of various shapes, sizes and types, found on the ground

Question 35

Where is a recessional moraine found?

Answer 35

A recessional moraine is material found at the snout of the glacier as it retreats or advances.

Question 36

What is a Drumlin?

Answer 36

- Drumlins are smooth mounds of deposited material that reaches about 1 kilometre+ in length and 500m or so in width and 50+ metres in hight. - It is thought that they were formed when the ice became overloaded with sediment. (A group of drumlins is called a SWARM)

Question 37

What are striations?

Answer 37

They are scratches on material that the glacier is carrying. They give an indication of the direction that the glacier was traveling in.

Question 38

What are erratics?

Answer 38

Erratics are large boulders that have been carried by the glacier and then deposited in an area of different rock types, so that they look completely out of place.

Question 39

What is an avalanche?

Answer 39

An avalanche is a massive snow and ice that moves very rapidly down a mountainside

Question 40

What are physical causes of an avalanche?

Answer 40

- Heavy snowfall - melting weakens the layers of snow and ice causing them to become unstable - small earthquakes

Question 41

What are human causes of an avalanche?

Answer 41

People skiing or snowboarding can cause increased pressure on the layers of snow, this can cause an avalanche.

Question 42

What is the result of an avalanche?

Answer 42

- lives are lost - buildings are destroyed - people are buried and injured

Question 43

What are ways in which to prevent an avalanche?

Answer 43

- Experts will monitor the state of the snow and decide if its safe to be skied or snowboarded on - weather warnings can be issued on areas thought to be at risk - wooden fences can be built on a slope to hold back snow - trees can hold the snow together - trees also break up small avalanches preventing them from becoming dangerous - roads and buildings that are at risk can have shutes built to protect them