Lecture 15: Cryosphere Part 1

Question 1

What is the Cryosphere?

Answer 1

Encompasses the parts of the Earth where water freezes for at least part of the year, or remains perennially frozen.
-The frozen water part of the Earth’s system

Question 2

What is albedo?

Answer 2

Fraction of light that is reflected by a body or surface.

-Snow has a high albedo

Question 3

What are the four components of the Cryosphere? (that we are studied in class)

Answer 3

• Snow
• Permafrost
• Sea ice
• Glaciers

Question 4

What is an annual snowline?

Answer 4

Marks the boundary of areas that have snow year-round with those that don’t.

Question 5

What controls the shape and size of the snowline?

Answer 5

-winter snow accumulation and summer melting

Question 6

How does the elevation of the snowline correlate to temperature?

Answer 6

• Lower in polar areas where temperature is colder

- Lower in coastal areas where there is more moisture

Question 7

What is permafrost and what does it store?

Answer 7

Ground (sediment or rock) that remains frozen for 2 or more years.
-stores a lot of carbon because it freezes organic matter- preventing it from rotting

Question 8

What is the active layer?

Answer 8

The surface layer of the frozen sediment or rock that thaws seasonally.

Question 9

How does an ice wedge form?

Answer 9

In the fall/early winter, the ground can get very cold and contracts, which causes it to crack.

• Snow blows into this crack and seasonal melt allows water to fill it.
• Then it refreezes during the next winter, as the ice expands which causes a wedge to open in the ground. An ice wedge is the result of this processes repeating

-Oldest ice in the northern hemisphere

Question 10

How are solifluction lobes formed?

Answer 10

They are formed by downslope creep of the active layer when it is saturated.

Question 11

What is a patterned ground?

Answer 11

geometric patterns that form on surfaces experiencing intense freezing and thawing.
-e.g. Polygonal ground formed by ice wedges

Question 12

How does sea ice form?

Answer 12

• Air temperature falls below freezing point of seawater
• Initially small needles of ice form, frazil ice
• Eventually freeze together and form continuous ice cover

Question 13

What are the two kinds of sea ice?

Answer 13

1. Pancake ice

2. Nilas

Question 14

Where do pancake ice form?

Answer 14

Rough water

Question 15

Where do nilas form?

Answer 15

Smooth water

Question 16

Where do we find sea ice?

Answer 16

• Antarctic

- Arctic

Question 17

What is the sea ice like in the Antarctic?

Answer 17

Surrounds the continent, is largely seasonal

Question 18

What is the sea ice like in the Arctic?

Answer 18

Is an ocean covered in sea ice, extends into the Bering Sea, has perennial ice.

Question 19

What is polar amplification?

Answer 19

Northern latitudes experiencing much greater warming

-one reason is due to loss of sea ice (Arctic)

Question 20

Why is sea ice an important component of the Earth’s system?

Answer 20

1. Increases surface albedo
2. Insulates the ocean from heat loss or gain
3. Provides a barrier to exchanges between ocean and atmosphere
4. Salt ejected by growing sea ice alters the density of water and helps drive ocean circulation
5. A major component of polar ecosystems
6. Arctic sea ice, covering the Arctic ocean, is particularly sensitive to climate change and connected to global climate

Question 21

How does sea ice affect the ocean circulation?

Answer 21

As sea ice freezes, salt is ejected making the surface ocean water saltier. This cold and salty water is denser and sinks into the deep ocean basins, which drives deep ocean circulation.
-(AABW) Antarctic Bottom Water
-(NADW) North Atlantic Deep Water
As the Arctic sea ice shrinks, ocean waters becomes less salty and warmer, thus less dense, slowing the NADW

Question 22

How does sea ice affect the atmosphere?

Answer 22

• Sea ice isolates the ocean from the atmosphere, cutting off heat exchange.
• Sea ice also reflects light and heat
• Contributes to the coldness of polar regions, helping produce a steep temperature gradient between the equator and the poles, which drives atmospheric circulation

Question 23

What is a glacier?

Answer 23

Land-based mass that flows.

Question 24

How does it flow?

Answer 24

From high elevations to low elevations.

Question 25

What are the types of glaciers?

Answer 25

1. Continental

2. Alpine

Question 26

What is a continental glacier?

Answer 26

Glaciers so large that flow is unaffected by underlying topography.

Question 27

What is an alpine glacier?

Answer 27

Glaciers where flow is controlled by topography.

Question 28

What are the five types of alpine glaciers?

Answer 28

1. Cirque glaciers
2. Valley glaciers
3. Piedmont glaciers
4. Fjord/tidewater glaciers
5. Ice field

Question 29

What is a valley glacier?

Answer 29

Ice accumulated in topographically high regions that flow down mountain valleys.
-May produce icebergs if they terminate in water

Question 30

What is a cirque glacier?

Answer 30

Small glaciers in a cirque (a bowl-shaped) depression on the side of a mountain formed by glacial erosion
-Part of the glacier can hang out of the cirque, becomes a hanging glacier

Question 31

How is a fjord/tidewater glacier formed?

Answer 31

When valley glaciers flow into submerged valleys and terminate in the ocean.

Question 32

What is a piedmont glacier?

Answer 32

When a valley glacier flows out into a broad lowland or another larger valley.

Question 33

What is an ice field?

Answer 33

Coalesced valley glaciers that cover mountain highlands and form a mass of glacier ice. Similar to an ice cap, but smaller and lacking a dome-like shape.

Question 34

What are the two types of continental glaciers?

Answer 34

1. Ice cap

2. Ice sheet

Question 35

What is an ice cap?

Answer 35

• Miniature ice sheets
• Not controlled by underlying topography
• Form in polar and subpolar regions that are relatively flat and high in elevation

Question 36

What is an ice sheet?

Answer 36

Huge masses of glacial ice where flow is unconstrained by topography.

• Flow from the highest elevation areas of the ice sheet radially outwards
• Generally slow moving, although outlet glaciers and “ice streams” are locations of faster movement

Question 37

What is an ice shelf?

Answer 37

Floating ice that is fed from mainland glaciers.