Glaciers

Question 1

What is the cryosphere?

Answer 1

All frozen water on the earth

Question 2

What is albedo?

Answer 2

The percentage of light reflected back off the ice

Question 3

Define normal fluids

Answer 3

They deform instantly when a shear is applied upon them

Question 4

Define non-newtonian fluids

Answer 4

Their viscosities and rate of deformation decrease as shear stress is increased

Question 5

What are the two conditions needed for glaciation?

Answer 5

1. precipitation

2. Temperatures that will preserve the ice over the summer

Question 6

What kind of competence do glaciers have?

Answer 6

Very high

Question 7

A poorly sorted mixture of mud, sand and gravel is called…

Answer 7

diamicton

Question 8

What is till?

Answer 8

Diamicton lain down from glacier ice, has not been disturbed since.

Question 9

What is an esker

Answer 9

An elongated ridge of sand and gravel generated by meltwater flowing from to the front of the glacier under pressure and depositing the sediment

Question 10

True or false: water is the only chemical on earth to occur naturally in all three phases

Answer 10

True

Question 11

Define permafrost

Answer 11

Ground that is constantly at a temperature below 0 degrees Celsius

Question 12

When sea ice forms, what two things occur?`

Answer 12

Dense, cold water that plunges to the ocean bottom

Salt is rejected when the ice forms, therefore the ice is primarily fresh.

Question 13

What is the thickness of sea ice

Answer 13

Never more than several meters

Question 14

What is another name for normal fluids, and please define them

Answer 14

1. Newtonian fluids

2. They deform instantaneously with applied shear, and viscosity increases linearly when shear stress is increased

Question 15

some fluids are non-newtonian. what does this mean?

Answer 15

Their viscosities decrease as shear stress is increased.
OR
They exhibit shear thickening behaviour, where viscosity increases as shear stress increases

Question 16

Because ice can behave as both a solid and a fluid, what is ti said to be? (2 things)

Answer 16

1. viscoelastic

2. exhibits considerable shear thinning behaviour (shear stress needs to be really high before it flows)

Question 17

The two main types of glaciers

Answer 17

ice sheets and alpine glaciers

Question 18

where are the two main ice sheets?

Answer 18

over Antarctica and greenland

Question 19

What are ice domes?

Answer 19

elevated areas of ice from which ice flows radially.

Question 20

What is an ice stream?

Answer 20

areas on the extremities of ice sheets, where ice will flow several magnitudes faster than the ice around it.

Question 21

Define calving

Answer 21

Occurs when an ice stream meets the ocean. It starts to float, thin considerable, form an ice shelf, which then breaks off into icebergs.

Question 22

What two places allow for the formation of ice sheets and glaciers?

Answer 22

High altitude and latitude

Question 23

What is firn?

Answer 23

Snow that has survived the summer melt season

Question 24

Why can glacier formation be equated to metamorphic rock?

Answer 24

Glaciers form by recrystallization of
snow flake crystals, just like a metamorphic rock forms by recrystallization of
an igneous, sedimentary or metamorphic rock precursor.

Question 25

What is an accumulation zone?

Answer 25

an inner zone of mass gain on an ice sheet

Question 26

What is an ablation zone?

Answer 26

An outer zone on an ice sheet of mass loss

Question 27

What is the equilibrium line on an ice sheet?

Answer 27

Where accumulation = ablation

Question 28

What is meant by positive mass balance?

Answer 28

to get a glacier, and to maintain it, accumulation must exceed ablation

Question 29

Three mechanisms by which a glacier moves

Answer 29

a) ice deformation,
b) basal sliding, and
c) subsole deformation

Question 30

Define ice deformation

Answer 30

base of glacier below pressure melting point, so glacier frozen to the ground. Therefore, the only way the glacier moves is by deformation

Question 31

Define basal sliding

Answer 31

If the base of glacier is above the pressure melting point of ice, movement can occur by all three processes of movement.