Glaciated Landscapes and Change

Question 1

What do periglacial processes include?

Answer 1

• Nivation, frost heave, freeze thaw weathering, solifluction, high winds, meltwater erosion

Question 2

What are 4 unique periglacial landforms?

Answer 2

1. Ice wedges 2. Patterned ground 3. Pingos 4. Loess

Question 3

What are the three processes of accumulation?

Answer 3

1. Direct snowfall 2. Avalanches 3. Wind depostion

Question 4

What are the five processes of ablation?

Answer 4

1. Melting 2. Sublimation 3. Calving 4. Evaporation 5. Avalanches

Question 5

What are the three different processes that are important in the movement of glaciers?

Answer 5

1. Basal slip 2. Regelation creep 3. Internal deformation

Question 6

What are 5 factors that affect the rate of movement in glaciation?

Answer 6

1. Altitude 2. Slope angle/gradient 3. Ice thickness 4. Bedrock permeability 5. Variations in mass balance (ice temp, rates of ablation and precip)

Question 7

How and when were ice ages discovered?

Answer 7

In 1830s by Louis Agassiz in the Swiss Alps. Identified that they had occurred all over Europe, saw that certain areas had similar features

Question 8

What is the theory of Uniformitarianism?

Answer 8

The assumption that the same natural laws and processes that operate in our present day scientific observations have always operated in the universe in the past and apply everywhere in the universe

Question 9

What does glacial and interglacial periods mean?

Answer 9

Glacial - period of intense cold
Interglacial - period between glacial periods

Question 10

How have ice cores helped determine past climates?

Answer 10

Bubbles trapped in the ice contain CO2 from the atmosphere

Question 11

What epoch are we currently living in?

Answer 11

Quaternary epoch

Question 12

What are epochs?

Answer 12

Periods of geological time. These relate to times of the past where geological strata were laid down. Epochs denote changes such as mass extinctions

Question 13

What three epochs is the quaternary period divided into and explain them

Answer 13

1. Pleistocene - covers the beginning of the quaternary period, this is the age we will study in detail 2. Holocene - interglacial period of man 3. Anthropocene - begins from when there was significant human impact on Earth until now, including such things as biodiversity loss and climate change

Question 14

Does the Pleistocene epoch have multiple glacial and interglacial periods?

Answer 14

Yes, causes the landscape to remould and reshape each time, this makes it complex to reconstruct the past

Question 15

How many years roughly is there a new glacial or interglacial period?

Answer 15

Every 100,000 years

Question 16

Give another way glacial landscapes can be modified other than other glacial periods

Answer 16

Geomorphological processes

Question 17

What are stadials and interstadials?

Answer 17

Stadials - smaller fluctuations and shorter periods of intense cold
Interstadials - shorter periods of relative warmth
Recent ice core analysis show these to be sometimes quite abrupt changes

Question 18

Give the 5 types of glacial erosion

Answer 18

1. Quarrying 2. Plucking 3. Abrasion 4. Crushing 5. Basal melting. These all combine with subaerial freeze thaw and mass movement

Question 19

Give the 7 upland erosional features

Answer 19

1. Cirques/corries 2. Aretes 3. Pyramidal peaks 4. Glacial troughs 5. Truncated spurs 6. Hanging valleys 7. Ribbon lakes

Question 20

Give the 4 landforms due to ice sheet scouring

Answer 20

1. Roches moutonnees 2. Whalebacks 3. Knock and lochan 4. Crag and tail

Question 21

What is the pleistocene?

Answer 21

Covers the beginning of the quaternary period, glacial epoch. around 2,588,000 to about 11,700 years ago

Question 22

What is precession?

Answer 22

A gradual change, or wobble, in the orientation of Earth’s axis affects the relationship between Earth’s tilt and eccentricity

Question 23

When did the quaternary period start?

Answer 23

2.588 million years ago!!!!!!!! wow

Question 24

How many years of climate can ice cores track back to?

Answer 24

800,000 years

Question 25

What is the first milankovitch cycle theory and how often does this happen?

Answer 25

Eccentricity of orbit - happens every 100,000 years

Question 26

How often does axial tilt happen?

Answer 26

41,000 years

Question 27

How often does precession happen?

Answer 27

Every 21,000/22,000 years

Question 28

Spell the volcano in Iceland that sir wants you to spell for some reason

Answer 28

Eyjafjallajokull

Question 29

What are the three reasons for glacial deposition?

Answer 29

1. When the velocity is reduced 2. They become overloaded with debris 3. When ablation increases

Question 30

What are the six ice contact depositional features?

Answer 30

1. Erratics 2. Medial moraines 3. Lateral moraines 4. Recessional moraines 5. Terminal moraines 6. Drumlins

Question 31

What are the two types of till plains (lowland depositional features)?

Answer 31

1. Lodgement till 2. Ablation till

Question 32

Explain the eccentricity of orbit as a primary cause of climate change. 4 points

Answer 32

1. Elliptical earth orbital cycle to circular every 100,000 years 2. Amount of solar radiation received in high eccentricity orbit varies greatly, increase in magnitude of seasonal changes 3. Low eccentricity leads to low seasonality - promotes glaciation 4. As a result, temps at high latitudes in northern hemisphere increase

Question 33

Explain obliquity as a primary cause of climate change. 5 points

Answer 33

1. Axial tilt varies from 21.8 degrees to 24.4 degrees, currently at 23.5 , 2. 41,000 year timescale 3. Impacts intensity of light received at poles - seasonality of Earth 4. Less tilt=warmer winters but cooler summers - glaciers do not melt in summer - advance, low obliquity=low seasonality 5. Glaciers will reflect more of incoming solar radiation further cooling planet

Question 34

Give four different characteristics of glacial and fluvioglacial deposits

Answer 34

1. Stratification 2. Sorting 3. Imbrication 4. Grading

Question 35

Give three formations of fluvio-glacial ice contact features

Answer 35

1. Kames 2. Eskers 3. Kame terraces

Question 36

Give four fluvio-glacial proglacial features

Answer 36

1. Sandurs 2. Pro-glacial lengths 3. Meltwater channels 4. Kettleholes

Question 37

Explain precession as a primary cause of climate change in 5 points

Answer 37

1. The earth wobbles on its axis changing the point in time the earth is nearest the sun (21,000/22,000 year cycle) 2. Means that the North Pole points both towards and away from the sun increasing the variation in the irradiation of the Northern Hemisphere 3. Causes variation in summer and winter temperatures and so causes variations in ice volume 4. Precession (tilt direction) works in conjunction with eccentricity to control the level of insolation at 65 degrees north 5. Glaciation is favoured when the direction of the tilt is such that N.hemisphere summers are at the largest earth-sun distance

Question 38

How much do the Milankovitch cycles affect the temperature by?

Answer 38

1 to 1.5 degrees

Question 39

How many degrees change does there need to be for ice to form?

Answer 39

5 degrees

Question 40

Give an example of positive feedback

Answer 40

Small increases to snow and ice cover can raise surface albedo (the quantity of reflection of sunlight) - more solar radiation is reflected back into space - could lead to more snow and ice cover

Question 41

Give two examples of negative feedback

Answer 41

1. Increases global warming and industry leads to more evaporation which increases cloud cover - increased cloud cover reflects solar energy back into space - reducing the intensity of global warming 2. Ice sheet dynamics disrupt thermal heating circulation - warming waters in the Arctic disrupts ocean currents - less warm water from the gulf stream creating global cooling in N.Europe