❄️ glaciation sg4

Question 1

what does glaciofluvial mean

Answer 1

processes and landforms associated with actions of meltwater streams (post glacial)

Question 2

what is the hjulstrom curve

Answer 2

shows how velocity and particle size effects erosion, transportation and deposition

Question 3

what does sorted sediment mean

Answer 3

same size sediment found in same areas

Question 4

what does stratified sediment mean

Answer 4

layered sediment (eg biggest at bottom, smallest at top in layers)

Question 5

what is graded sediment

Answer 5

as you move across or down size of material goes from large to small

Question 6

what is attrition

Answer 6

when sediment collided together as it is transported in streams

Question 7

what is an esker

Answer 7

long winding ridge composed of stratified sand and gravel deposited by stream as it flows under glacier

Question 8

named example of an esker and it’s size

Answer 8

Mosedale esker in the lake district
- 200m long
- 50m wide
- 5m tall

Question 9

formation of an esker

Answer 9

• the glacier starts to retreat
• the stream of sediment under the glacier flows under hydrostatic pressure within tunnels
• deposition occurs as meltwater is released and loses energy
• glacier continues to retreat so the point of deposition moved backwards leaving a ridge of material

Question 10

how is an esker modified due to climate change

Answer 10

• variation warm periods = beaded esker (when it has bumps)
  - when there is a slower retreat due to colder temps the esker has a bump bc there is more time for sediment to deposit
• rapid warning = eskers may be washed away by meltwater
• biological weathering & stabilising by vegetation
• new eskers prone to slumping

Question 11

what is a kame

Answer 11

hill or hummock of stratified sand and gravel laid down by glacial meltwater

Question 12

how does a kame form

Answer 12

• warming temps cause meltwater stream to become overloaded with sediment
• stream flows into a glacial lake
• stream loses energy when it flows into lake so all sediment is deposited as a round hill

Question 13

how is a kame modified due to climate change

Answer 13

• new kames are prone to slumping
• vegetation stabilises kames = less wind erosion
• biological weathering by lichen & tree roots can change gradient

Question 14

what is an outwash plain

Answer 14

a flat expanse of glaciofluvial sediment in a proglacial area

Question 15

named example of an esker and area

Answer 15

• solheimajokvil in iceland
• 57km^2

Question 16

how does an esker form

Answer 16

• temps rise so glacier starts to retreat
• braided streams occur as water is forced around channel bars
• larger sediment closer to snout bc water loses hydrostatic pressure & velocity
• kettle holes often contain small lakes

Question 17

how is an outwash plain modified due to climate change

Answer 17

• plane colonisation occurs which stabilises some features such as channel bars making then more resistant to erosion
• chemical weathering occurs due to lichen