Glaciation ❄️

Question 1

When was the last Ice Age?

Answer 1

About 18,000 years ago

Question 2

Ice Ages have intermittent ..?.. ..?.. These are called ‘..?..’

Answer 2

Ice Ages have intermittent WARM PERIODS. These are called ‘INTERGLACIALS’

Question 3

What is the definition for: GLACIER?

Answer 3

GLACIERS are slow moving ‘rivers of ice’

Question 4

Give an example of a glacier in Europe!

Answer 4

An example of a glacier in Europe is: Mer de Glace, France

Question 5

What is the definition for: ICE SHEETS?

Answer 5

These are the large areas of thick ice found in Antarctica and Greenland

Question 6

What is the definition for: ICE CAPS?

Answer 6

These are smaller areas of thick ice

Question 7

What is the definition for: CREVASSES?

Answer 7

These are cracks in the ice

Question 8

What’s does the GLACIER SYSTEM consist of?

Answer 8

Inputs, transfers (flows), stores and outputs

Question 9

What are INPUTS?

Answer 9

INPUTS come from avalanches along the sides of the glacier but mainly from precipitation as snow.

Question 10

Explain STORAGE!

Answer 10

Over time snow accumulates and is compressed into ice. The water held in STORAGE is the glacier

Question 11

Under the force of gravity, the glacier ..?.. downhill

Answer 11

Under the force of gravity, the glacier FLOWS downhill

Question 12

Explain OUTPUTS!

Answer 12

Meltwater is the main OUTPUT from the glacier, along with some evaporation

Question 13

Explain the balance between INPUTS and OUTPUTS!

Answer 13

In winter: - inputs usually exceed outputs
near the head of a glacier.
(accumulation)
- Here the glacier advances.

In Summer: - Outputs will exceed inputs
(ablation)
- Here the glacier retreats.

Question 14

What are most of the world’s GLACIERS doing today?

Answer 14

They are retreating

Question 15

Summarise the first process in the glacier system: Frost Shattering!

Answer 15

-Water fills small cracks in the rock.
-At night (0-) the water in the cracks
freezes.
-When it warms up again (daytime) the frozen
water thaws.
-This process is repeated many many time
causing more cracks to start appearing in
the rock.
-This process is called FROST SHATTERING or FREEZE THAW WEATHERING.

Question 16

Explain/ summarise the second process in the glacier system: Abrasion!

Answer 16

The material frozen into the glacier scours the valley sides and base. This is sand-papering effect, similar to corrasion by a river but on a much larger scale.

Question 17

Explain/ summarise the third and final process of the glacier system: Plucking!

Answer 17

The water at the bottom of the glacier freezes onto the rock on the valley base. As the glacier moves, the Rick is pulled away from the valley base. Plucking mainly occurs when the rock is well-jointed.

Question 18

Explain/ summarise a CORRIE:

Answer 18

-Snow collects in a natural hollow on the side of a mountain.
-Overtime more snow gals into the hollow, this
extra weight compressing the snow underneath
and turning it to ice.
-The hollow is deepened by abrasion and plucking.
-This leads to an ‘armchair’ shape and causes a
‘rock lip’ to be formed.

Question 19

Describe an ARÊTE:

Answer 19

An ARÊTE is a very narrow ridge on a mountain and is sometimes described like a ‘knife edge.’

Question 20

Describe and then give an example of a Pyramidal peak:

Answer 20

A PYRAMIDAL PEAK is an angular sharply pointed mountain peak which results from CORRIE erosion due to multiple glaciers diverging from a central point.

An example of a PYRAMIDAL PEAK is: The Matterhorn in the Alps

Question 21

Describe a GLACIAL TROUGH/U-SHAPED VALLEY:

Answer 21

This is when glaciers cut distinctive U-SHAPED VALLEYS with a flat floor and steep sides

Question 22

Describe a TRUNCATED SPUR:

Answer 22

As the valley glacier moves, abrasion and plucking erode the protruding tips of the spurs leaving them truncated

Question 23

Describe a HANGING VALLEY:

Answer 23

This is a side valley that enters a main valley at a height high above the main valley floor

Question 24

Describe a MISFIT STREAM:

Answer 24

This is a stream that is too small to have eroded the U-SHAPED VALLEY in which it flows

Question 25

Describe MORAINES:

Answer 25

This is a type of landform that is created when a glacier deposits the material (till) that it has been transporting. There are several types of Moraine - Lateral, Medial, Ground, Recessional and terminal.

Question 26

Describe DRUMLINS:

Answer 26

Drumlins are formed of till. They are elongated features that can reach a kilometre or more in length, 500m or so in width and over 50m in height

Question 27

Describe GLACIAL STRIATIONS:

Answer 27

These are scratches or gouges cut into bedrock by glacial abrasion. They indicate the direction of the ice flow

Question 28

What is the definition for: ICE AGE?

Answer 28

An ICE AGE is a period when there is a long-term reduction in the temperature resulting in the presence or expansion of ice

Question 29

What is the definition for: AVALANCHE

Answer 29

An AVALANCHE is a mass of snow and ice that moves very rapidly down a mountainside.

Question 30

What are the NATURAL causes of avalanches?

Answer 30

-In spring melting weakens the layers of snow and ice causing them to become unstable. -A small earthquake.

Question 31

What are the HUMAN cause of avalanches?

Answer 31

-People skiing and snowboarding

Question 32

Describe ERRATICS:

Answer 32

An ERRATIC is a boulder that is different to the bedrock upon which it is sitting. They have been transported and deposited by a glacier. Therefore ERRATICS are useful indicators of patterns of former ice flow

Question 33

Explain summarise a RIBBON LAKE:

Answer 33

-Narrow lakes found on the valley floors of glacial troughs. -When a glacier moves along its valley, softer rock is eroded more easily. -When the glacier retreats, deeper sections fill with meltwater and become lakes. -Deposition of Moraine across the valley can also act as a dam, trapping the meltwater and thereby creating a ribbon lake.

Question 34

What is an INTERGLACIAL?

Answer 34

A period of time between one Ice Age and another Ice Age

Question 35

Describe GROUND MORAINE:

Answer 35

This is MORAINE that is dragged beneath a glacier and forms part of the valley floor

Question 36

Describe LATERAL MORAINE:

Answer 36

This is MORAINE that is produced from frost-shattering of the valley sides and is carried at the sides of the glacier

Question 37

Describe TERMINAL MORAINE:

Answer 37

This is MORAINE that is found at the snout (end of the glacier) and marks the maximum advance of a glacier. It is made up of deposited material. The glacier retreats here!

Question 38

Describe MEDIAL MORAINE:

Answer 38

This is MORAINE that is found in the centre of a glacier

Question 39

Describe RECESSIONAL MORAINE:

Answer 39

This is MORAINE that marks interruptions in the retreat of the glacier

Question 40

List the FOUR ways that we can reduce the hazard of avalanches:

Answer 40

1. Building wooden fences on a slope to hold back the snow. 2. Trees also help because they hold the snow pack together. 3. Trees will also break up smaller avalanches, preventing them from becoming too dangerous. 4. Roads and buildings can have shutes built to protect them.