Glaciation

Question 1

What is Abrasion?

Answer 1

Erosion caused by rocks and boulders in the base of the glacier, acting like a giant file scraping blocks below.

Question 2

What is an Arete?

Answer 2

A sharp ridge formed between 2 corries, cutting back by process of erosion.

Question 3

What is bulldozing?

Answer 3

Ice pushes material of all shapes + sizes as it moves forward.

Question 4

What is a corrie?

Answer 4

A hollow in the mountainside formed by glacial erosion, rotational slip and freeze thaw weathering.

Question 5

What is a drumlin?

Answer 5

A hill made up of glacial till deposited by a moving glacier, usually elongated.

Question 6

What is an erratic?

Answer 6

Rocks which have been transported and deposited by a glacier.

Question 7

What is freeze-thaw weathering?

Answer 7

Water enters cracks in the rock. When temperatures drop, the water freezes and expands causing the crack to widen. The ice melts and water makes its way deeper into the cracks. The process repeats itself until the rock splits entirely.

Question 8

What is a glacial trough?

Answer 8

A widened and deepened, river valley, caused by erosive action of glaciers.

Question 9

What is a hanging valley?

Answer 9

A tributary valley to the main glacier, too cold and too high for ice to easily move.

Question 10

What is moraine?

Answer 10

Frost-shattered rock debris and material eroded from the valley floor.

Question 11

What is outwash?

Answer 11

Material deposited by melt water streams in front of and under the glacier.

Question 12

What is plucking?

Answer 12

Erosion where melt water in the glaciers freezes onto rocks, as the ice moves forward, it plucks it out.
(like waxing)

Question 13

What is a pyramidal peak?

Answer 13

Several corries cut back and meet, the mountain takes the form of a steep pyramid.

Question 14

What is a ribbon lake?

Answer 14

Elongated, narrow lake found in glaciated valleys formed in locations where the glacier had more erosive power.

Question 15

What is rotational slip?

Answer 15

Ice moves in a circular motion. This process can help to erode hollows and deepen hollows into a bowl shape.

Question 16

What is till?

Answer 16

An unsorted mixture of sand, clay and boulders carried by a glacier and deposited.

Question 17

What is a truncated spur?

Answer 17

Former valley spur which has been sliced off by a valley glacier.

Question 18

What are low lands?

Answer 18

Lowlands are close to or below 200m above sea level.
An example is Fens, East Anglia.

Question 19

What is an example of low lands?

Answer 19

Fens in East Anglia.

Question 20

What are uplands?

Answer 20

Normally made up of mountains or high hills.
They are areas over 600m above sea level.
Examples are the Cumbria mountains in the Lake District

Question 21

What is an example of uplands?

Answer 21

Cumbria mountains in the Lake District.

Question 22

When was the last ice age?

Answer 22

20,000 years ago.

Question 23

How thick was the ice in the last ice age?

Answer 23

3km thick.

Question 24

What is a glacial period?

Answer 24

When global temperatures drop to an average of 11 degrees from the current 15 degrees.

Question 25

Why do large glaciers flow down hill?

Answer 25

Due to gravity.

Question 26

What is an interglacial period?

Answer 26

Retreat of ice to higher longitudes or latitudes.

Question 27

Which places were covered in ice in the last ice age?

Answer 27

• UK
• Canada
• USA
• Northern Europe

Question 28

What is a glacier?

Answer 28

A moving body of ice.

Question 29

How do glaciers form?

Answer 29

1. Glaciers form when snow remains in the same area year-round, slowly transforming into ice.
2. Each year, new layers of snow bury and compress the previous layers.
3. This compression forces the snow to re-crystallize, forming grains similar in size and shape to grains of sugar.
4. Gradually the grains grow larger and the air pockets between the grains get smaller, causing the snow to slow to slowly compact and increase in density.
5. After about 2 winters, the snow turns into firn/neve - a middle state between snow and glacier ice.
6. For most glaciers, this process takes more than a 100 years.

Question 30

What is glacial transport?

Answer 30

• As glaciers move, they transport debris (till)

Question 31

What is subglacial material?

Answer 31

Some material is plucked or abraded from the bedrock un

Question 32

What is Englacail material?

Answer 32

Some material falls into crevasses (cracks in the ice) and is transported inside the ice of the glacier.

Question 33

What is supraglacial material?

Answer 33

Some material falls onto the ice from surrounding mountainsides so it is carried on top of the glacier.