Glaciers as Natural Systems

Question 1

Give the inputs of a glacier

Answer 1

Snow
Avalanche
Water
Rocks
Fern lost in summer
Snow that survived the melting 
Rock picked up from moving 
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Question 2

Give some stores, processes and transfers of a glacier

Answer 2

Ice 
Rock
Fern becomes compressed by new snow 
Accumulation of snow 
Erosion of landscape 
Transportation of ice

Question 3

Give some outputs of. a glacier

Answer 3

Meltwater 
Evaporation 
Sublimation
Rock debris
Carving

Question 4

Why can a glacier be considered as an open system

Answer 4

Because it contains both inputs of matter and energy, as well as outputs such as water and snow

Question 5

Give the first step in the formation of a glacier

Answer 5

Snowfall - for a glacier to form, the annual accumulation of snow must be greater than the amount of melting each year.
Often occurs in shady hollows downwind of mountains

Question 6

Give the 2nd step in the formation of a glacier

Answer 6

After a few days, the delicate snowflakes begin to break up.
This process is accelerated by snow melting at the surface, producing meltwater which percolates into the snowpack where it refreezes in colder, deeper layers

Question 7

Give the 3rd step in the formation of a glacier

Answer 7

Gradually snowflakes are squashed by the weight of more snow falling on top and they change into small, round granules - after a year this = firn

Question 8

Give the 4th step in the formation of a glacier

Answer 8

The weight of the overlying snow continues to squash grains together and squeezes the air out (diagenesis).
After 10-20 years, the firn becomes ice

However, this process can take 100s of years in Greenland or Antarctica where there is no surface melting and a very gradual build-up of snow

Question 9

Give the final step in the formation of a glacier

Answer 9

The ice becomes thicker and then the ice starts to move down the slope due to the pull of gravity. When the ice starts to move downhill it’s known as a glacier

Question 10

Give 3 positive feedback cycles in glaciers

Answer 10

Increased warming - Melting sea ice - Less albedo - More heat absorbed

Increased warming - Melting snow - More bare rock exposed - higher heat absorption

Increased warming - Melting of tundra surface and permafrost - Methane and CO2 released

Question 11

Give a negative feedback cycle for glaciers

Answer 11

Warming temperatures - Expose more land - More plants can survive - More CO2 absorption - Cooler temperatures

Question 12

What is the ablation zone

Answer 12

Output of the glacier - lower altitude and warmer climate encourages melting

Question 13

In the ablation zone, the ratio of ice to rock debris in the glacier are greatly……………

Answer 13

Reduced

Question 14

What is the equilibrium line

Answer 14

The point where both accumulation and ablation are equal

Question 15

Give 4 types of cold environments and their location

Answer 15

Polar - High latitudes within Arctic and Antarctic circles

Glacial - Any location associated with active glaciers

Alpine - Mountain areas, Alps and North American Rockies

Periglacial - Mainly at the margins of glacial and polar environments such as Alaska, Northern Canada and Siberia

Question 16

Give the climate conditions for polar

Answer 16

Worlds most extreme conditions, with temperatures falling as low as -50 to -60ºC

Very high wind speeds + low precipitation

Human activities severely restricted

No natural vegetation

Question 17

Give the climate conditions for glacial

Answer 17

• Very cold winter temperatures and significant precipitation in the form of heavy winter snowfall, encouraging glacial growth
• More moderate summers encourage glacial flow
• Human activities = tourism like skiing
• Some limited alpine vegetation will exist on the fringes of glacial environments

Question 18

Give the climate conditions for Alpine

Answer 18

• Heavy winter precipitation with very cold temperatures averaging -10ºC or less (dictated by high altitude)
• Wide annual temperature range owing to warm, sunny summers averaging 20ºC or more
• Human activities such as agriculture and tourism can thrive (ideal for HEP)
• Rich meadows, grasslands and trees (mostly coniferous)

Question 19

Give the climate conditions for periglacial

Answer 19

• Cold temperatures maintain permanently frozen ground (permafrost) though not covered by ice
• Brief warm summers allow surface layers to thaw making soil conditions marshy
• Limited human activities
• Tundra vegetation comprises low growing plants and shrubs with few trees

Question 20

Climate is never………

Answer 20

Stable

Question 21

What is the name of our Ice age and what is an ice age

Answer 21

Quaternary Ice Age - began 2 million years ago

Ice ages are periods when there are ice sheets and glaciers present on Earth

Question 22

Ice masses cover …% of the Earths land area today

Answer 22

10

85% of ice is contained in the Antarctic sheet

Question 23

What was the last glacial period called

Answer 23

Devensian glacial - the maximum extent of glaciers occurred between 20,000 and 18,000 years ago when ice covered 30%

Question 24

How low were sea levels in Devensian glacial

Answer 24

100m lower - no English Chanell

Question 25

Give 3 long term climate change theories (Milankovitch)

Answer 25

Orbit Tilt Wobble

Question 26

How does the Earth's 95,000-year orbit affect climate change

Answer 26

The Earth's orbit stretches from being nearly circular to an elliptical shape and back in a cycle of 90,000 years Glacials occur when the orbit is almost circular and interglacials occur when ut is more elliptical

Question 27

How does the Earth's 42,000-year tilt affect climate change

Answer 27

The Earth's axis varies from its plane of orbit between 21.5º and 24.5º. When the tilt increases, summers will be hotter and winters colder - leading to conditions favouring interglacials

Question 28

How does the Earth's 21,000-year-old wobble affect climate change

Answer 28

As the Earth slowly wobbles through space, its axis describes a circle once every 21,000 years At present, the Earth is closest to the sun in the northern hemisphere's winter and furthest away in the summer. This makes winters mild and summers cool - ideal conditions for glacials to develop.

Question 29

Give the climate in cold environments

Answer 29

- Temperatures are close to or significantly colder than freezing - Liquid water is limited to certain times of the year - Snowfall varies - not much in polar regions but lots in coastal + mountainous environments

Question 30

Give the soils in cold environments

Answer 30

Weathering is limited due to the lack of liquid water and vegetation - little organic matter + decomposers which only thrive in warm conditions Soil development is therefore really slow and any that do develop will be very thin, acidic and waterlogged + frozen

Question 31

Give the vegetation in cold environments

Answer 31

Vegetation requires soil to act as an anchor and to extract nutrients and minerals from Many cold environments don't have vegetation so there is no fertlie soil - mostly lichens on bare rock

Question 32

How much of Antarctica is ice-free

Answer 32

0.4% - 90% of this is able to support soil

Question 33

What are the soils like in Antarctica

Answer 33

Cold, desert soils with deep-set permafrost evident in lower layers The surface layer is often strewn with boulders and gravel - created due to the extreme weathering process

Question 34

How many native plants are there in Antarctica and what are they

Answer 34

2 Antarctic Hair Grass Antarctic Pearlwort Found in small groups near the shore of the West coast - temperatures there are milder with more precipitation

Question 35

How have plants adapted to Antarctica

Answer 35

- Able to survive under a snow layer + photosynthesis in very cold environments - Leaf size is often small to prevent moisture loss + have a fur-like covering - Plants produce flowers which are cup-shaped to focus the sun's rays to the centre to assist photosynthesis