Glaciers

Question 0

What’s an arête?

Answer 0

Sharp, knife like ridge formed between two corries

Question 1

What’s abrasion?

Answer 1

Erosion caused by rocks and boulders which are picked up as the glacier moves. These rocks in the base of the glacier acting like a giant file scratching and scraping the rocks below

Question 2

Two other names for a corrie?

Answer 2

Cirque, cwym

Question 3

What’s a burgschrund?

Answer 3

A deep crevasses found at the back wall of a corrie, formed as the ice moves away downhill. This may have been an important role in the processes leading to the deep erosion of the cirque basin

Question 4

What’s boulder clay?

Answer 4

An insorted mixture of sand clay and boulders carried by a glacier and deposited as ground moraine over a large area

Question 5

What’s a corrie?

Answer 5

Armchair shaped hollow in the mountainside formed by glacial erosion and freeze-thaw weathering. This is where the valley glacier begins.

Question 6

What’s a crevasse?

Answer 6

A deep crack on the surface of an ice sheet or valley glacier

Question 7

What are erratics?

Answer 7

Huge rocks which have been transported and deposited by a glacier some distance from their source region

Question 8

What’s erosion?

Answer 8

The wearing away of land by rivers, ice sheets, waves and wind

Question 9

What’s a fjord?

Answer 9

A long narrow steep sided inlet formed by glaciers as later drowned by a rise in sea level. Fjords are often over 3km deep

Question 10

What’s freeze thaw weathering? (Frost shattering)

Answer 10

It occurs in cold climates when temperatures are often around freezing point and where exposed rocks contain many cracks. Water enters the cracks during the warmer day and freezes during the colder night. As the water turns into ice it expands and exerts pressure on the surrounding rock, causing pieces to break off

Question 11

What’s a glaciated valley/u shaped valley?

Answer 11

a river valley widened and deepened by the action if glaciers (ice sheets) ; they become u-shaped instead I the normal v-shape of a river valley

Question 12

What’s a glacier?

Answer 12

A sheet of ice that moves slowly down a river valley under the influence of gravity. Often described as a river of ice

Question 13

What’s a hanging valley?

Answer 13

A tributary valley to the main glacier, too cold and high up for ice to be able to easily move. It therefore was not eroded as much as the lower main valley, and today is often the sure for a waterfall crashing several hundred metres to the main valley floor

Question 14

What’s the ice age?

Answer 14

A period of colder climate when ice sheets form on the land causing a lowering of sea level

Question 15

What’s ice movement?

Answer 15

When under pressure, ice behaves as jelly and flows with the aid if gravity and melt water lubrication. The melting point of ice at the base of the glacier can be lower than 0c due to the pressure of weight

Question 16

What’s an ice sheet?

Answer 16

Huge mass of ice covering the landscape that moves very slowly. Only the mountain peaks protrude above the ice

Question 17

What’s an interglacial?

Answer 17

A warmer spell between ice ages, lasting about 10,000 years

Question 18

What’s a misfit stream?

Answer 18

After the ice has melted and the river returns to the valley, it often looks tiny and out of place

Question 19

What are moraines?

Answer 19

Frost shattered rock debris and material eroded from the valley floor and sides transported and deposited by glaciers

Question 20

What’s physical weathering?

Answer 20

The disintegration of rock into smaller pieces without any chemical change in the rock; this is most likely in areas of bare rock where there is no vegetation to protect the rock from extremes of weather e.g. Freeze-thaw and exfoliation (or onion weathering)

Question 21

Whats plucking?

Answer 21

A type of erosion where melt water in the glacier freezes onto rocks and as the ice moves forward it plucks/pulls out large pieces along the joints

Question 22

What’s a pyramidal peak?

Answer 22

Where several cirques cut back to meet a central point, the mountain takes the form of a steep pyramid eg the Matterhorn

Question 23

What’s a ribbon lake?

Answer 23

Long narrow lakes found in glaciated valleys formed in locations where the glacier had more erosive power eg in areas of softer rock where the valley gradient temporarily steepened or a tributary glacier joined the main valley

Question 24

What’s roches moutonnées?

Answer 24

Rocks looking like a sheeps head, one side smoothed and polished, the other plucked and jagged

Question 25

What’s rotational movement?

Answer 25

Avalanches of snow collecting at the back wall of a cirque exert great pressure, forcing the ice out of the front of the hollow in a rotational movement, similar to the pushing of jelly from a bowl

Question 26

What’s sea level changes?

Answer 26

Changes in the level of the sea against the land are caused by either the building up of melting polar ice caps or by rising or falling of land levels

Question 27

What’s scree?

Answer 27

A slope of loose, large angular rocks broken away from the mountainside by freeze-thaw weathering

Question 28

What’s a snout?

Answer 28

The end of a glacier where the melting occurs

Question 29

What’s a snowline?

Answer 29

The altitude where permanents now begins in mountainous regions

Question 30

What’s a spur?

Answer 30

A narrow neck of highland extending into a river valley, often forming the divide between two tributaries

Question 31

Whats a tarn?

Answer 31

A deep circular lake filling a corrie

Question 32

What’s a terminal moraine?

Answer 32

A prominent ridge of rock debris dumped at the end of a glacier and formed of unsorted boulders, sand, gravel and clay

Question 33

What’s a truncated spur?

Answer 33

A former river valley spur which has been sliced off by a valley glacier

Question 34

What’s weathering?

Answer 34

The break down or decomposition of rock by biological, physical or chemical processes