Cold Environments

Question 1

What is albedo?

Answer 1

Where snow and ice reflect most incoming solar radiation, creating a permanent deep freeze

Question 2

How does frost weathering work?

Answer 2

Water, trapped in confined rock joints or crevasses, expands by 9% of its volume on freezing, which shatters the rocks

Question 3

What several factors control the effectiveness of freeze-thaw weathering

Answer 3

The number of freeze thaw cycles
The availability of moisture
The density of jointing I’m rocks

Question 4

What are glaciers?

Answer 4

Are large bodies of ice formed from compressed snow

Question 5

Why do glaciers move?

Answer 5

They move downslope due to their own weight and gravity

Question 6

What are the three main types of glaciers?

Answer 6

Ice sheets
Ice fields (ice caps)
Valley glaciers

Question 7

Why do ice sheets submerge the landscape?

Answer 7

Because they often are 2-3km thick

Question 8

What is the largest type of glacier?

Answer 8

Ice sheets

Question 9

What are island peaks surrounded by seas of ice due to being covered by glaciers called?

Answer 9

Nunataks

Question 10

What are ice fields?

Answer 10

Miniature ice sheets covering areas less than 50000 km

Question 11

What are valley glaciers?

Answer 11

Giant tongues of ice that flow down from the snow line in mountainous regions

Question 12

What are small mountain glaciers called?

Answer 12

Cirque glaciers

Question 13

Where are small mountain glaciers often confined to?

Answer 13

Bowl-shaped depressions at the head of glacial valleys

Question 14

What are valley glaciers that flow from ice fields called?

Answer 14

Outlet glaciers

Question 15

What are valley glaciers which leave the mountains and spill into lowland regions before merging called?

Answer 15

Piedmont glaciers

Question 16

What are the three steps in the forming of glacier ice?

Answer 16

Snow
Firm
Glacier Ice

Question 17

What is ablation?

Answer 17

Melting and sublimation

Question 18

What converts snow into firn?

Answer 18

Freeze thaw and the weight of overlying snow

Question 19

What differs firn from glacier ice?

Answer 19

Firn still has some air left

Question 20

How long does the formation of glacier ice take?

Answer 20

40-50 years

Question 21

What controls the long term behaviour of glaciers?

Answer 21

Changes in mass balance or annual budget

Question 22

What does a positive balance do to a glacier?

Answer 22

Increases total mass of ice, causing glaciers to advance

Question 23

What does a negative balance do to a glacier

Answer 23

Reduces the ice mass and results in glacier retreat

Question 24

Where does snow accumulate on a glacier?

Answer 24

The zone of accumulation

Question 25

Where does snow melt

Answer 25

The zone of ablation

Question 26

What did research in the Cascade Range in the U.S. Pacific Northwest find?

Answer 26

There were 16 years between 1984 and 2006 when glaciers had a cumulative negative mass balance

Question 27

What does glacier flow rate depend on?

Answer 27

Valley gradient and the base temperature

Question 28

What are the two types of glacier movement?

Answer 28

Internal deformation and basal sliding

Question 29

What is internal deformation?

Answer 29

Ice crystals in glacier rearrange into parallel layers and slide past each other

Question 30

What is internal deformation caused by?

Answer 30

Weight of the ice and gravity

Question 31

What is basal sliding?

Answer 31

Where meltwater lubricates the base of the glacier, reducing friction and allowing the ice to move freely

Question 32

When does basal sliding occur?

Answer 32

Either when: intense pressure causes melting and/or meltwater seeping down from the surface through cracks in the ice

Question 33

Where does ice melt?

Answer 33

High pressure regions

Question 34

Where does ice freeze?

Answer 34

Low pressure regions

Question 35

What two locations do cold environments form?

Answer 35

High latitudes and mountains

Question 36

How do crevasses form?

Answer 36

When fracturing and faulting of ice occurs at the surface layers of a glacier

Question 37

What is a moraine?

Answer 37

Deposits of rock left by glaciers

Question 38

What are the three types of moraines?

Answer 38

Terminal Lateral Medial

Question 39

What are terminal moraines?

Answer 39

Moraines found at the terminus or the furthest (end) point reached by a glacier

Question 40

What are lateral moraines?

Answer 40

Moraines found deposited along the sides of the glacier

Question 41

What are medial moraines?

Answer 41

Moraines found at the junction between two glaciers

Question 42

What are surface moraines found on the surface referred to as?

Answer 42

Supraglacial

Question 43

What are moraines transported in ice called?

Answer 43

Englacial

Question 44

What are moraines transported below the glacier called?

Answer 44

Subglacial

Question 45

What often determines whether glaciers are Supraglaical or Englacial?

Answer 45

If the moraine is above the equilibrium line (englacial) or below (supraglacial)

Question 46

What are cirques?

Answer 46

Deep bowl-shaped depressions, enclosed on three sides by steep rock walls.

Question 47

What are cirques also called?

Answer 47

Corries

Question 48

Where are cirques found?

Answer 48

Mountain heads

Question 49

What are cirques the source of?

Answer 49

Valley glaciers

Question 50

On what slope side do Cirques develop?

Answer 50

North-east

Question 51

What is evidence that cirques develop on the North-east slopes?

Answer 51

71% of cirques develop on the north-east slopes of the Northern highlands in Scotland

Question 52

What are cirques a type of?

Answer 52

A feature of erosional landform

Question 53

What is the main cause of erosion in Cirques?

Answer 53

Rotational flow

Question 54

How does rotational flow work?

Answer 54

Cirques, under the force of gravity and lubricated by basal meltwater, slide downslope.

Question 55

Why does rotational flow contribute to glacial erosion?

Answer 55

It helps abrades the bedrock by plucking the bedrock at the top and using that rock to abrade the bedrock as it moves downslope

Question 56

Where do the rocks used for abrasion enter the glacier?

Answer 56

The bergschrund crevasse

Question 57

Define glacial erosion

Answer 57

Simply the carving and shaping of the land beneath a moving glacier

Question 58

Define plucking or quarrying

Answer 58

The erosion and transport of large chunks of rocks

Question 59

How does plucking work?

Answer 59

As a glacier moves over the landscape, water melts below the glacier and seeps into cracks within the underlying bedrock. This water freezes and melts, weakening the bonds holding pieces of bedrock in place. These pieces of rock can now be picked up or plucked from their rocky base and carried along with the moving glacier.

Question 60

Define abrasion

Answer 60

The erosion that occurs when particles scrape against each other.

Question 61

How does abrasion work?

Answer 61

The enormous weight of the glacier, along with rocks and sediment plucked up and clinging to its belly scratch and carve the rock surface below

Question 62

What is a small mountain lake of trapped water called?

Answer 62

A tarn

Question 63

What happens if a mountain is eroded by multiple glaciers?

Answer 63

It leaves a glacial horn

Question 64

What happens if two glaciers slide down opposite sides of a mountain?

Answer 64

An arete is formed

Question 65

What is an arete?

Answer 65

A sharp, narrow mountain ridge

Question 66

What is a roche mountonnee?

Answer 66

A mass of rock shaped by a moving glacier, with one side abraded and smooth while another is jagged and rough due to plucking