SG4: How landforms in glaciated landscapes are influenced in post glacial periods?

Question 1

What does post glacial period mean?

Answer 1

The meltwater period.

Question 2

What is a post glacial climate?

Answer 2

Glacial periods end when the global temperatures rise, then followers by shorter inter-glacials. In the post glacial period, temperatures often increase gradually.

Question 3

What is glaciofluvial?

Answer 3

Describes the processes and landforms associated with the action of meltwater streams from glaciers during post glacial times.

Question 4

What are the meltwater stream characteristics?

Answer 4

• Variable velocity
• Variable discharge
• Hydrostatic pressure.

Question 5

What are glaciofluvial landforms developed by?

Answer 5

Deposition.

Question 6

What are the proglacial features?

Answer 6

outwash plains

kettle lakes

Question 7

What are the ice contact features?

Answer 7

Esker

Kames

Question 8

What is an outwash plain?

Answer 8

A flat expanse of glaciofluvial sediment located in the proglacial area.

Question 9

A description of an outwash plain?

Answer 9

• Flat gentle sloping

- Found in front of glacier snout

Question 10

Name an example of an outwash plain?

Answer 10

Solheimajokull, Iceland 57km squared

Question 11

How is an outwash plain formed?

Answer 11

Proglacial streams that are present as temperatures melt and the glacier beings to retreat up the valley transport a lot of sediment, but highly variable discharge allows for it to be deposited.

Question 12

What is the subsequent modification of the outwatch plain?

Answer 12

• the advancing and retreating of this outwash plain causes more meltwater forming proglacial streams.
• Plant colonisation affects subsequent geomorphic processes on the outwash plain by weathering - causes biological weathering
• Over time plant colonisation is occurring on the exposed outwash plain.

Question 13

What is an esker?

Answer 13

A long winding (sinuous) rice composed of stratified sand and gravel deposited by meltwater streams.

Question 14

Description of an esker?

Answer 14

• Sinuous ridge of material
• Varies in height and length
• May be continuous or beaded
• Usually form parallel to valley sides along the valley floor.

Question 15

Give an example of an esker?

Answer 15

Mosedale esker, Lake district.

Question 16

How is an esker formed?

Answer 16

temperature rises so glacier begins to melt meaning discharge of meltwater streams and their sediment load increases. Eskers result from deposition of material carried by subglacial and englacial meltwater streams during the glacial period. Deposition occurs when pressure is released as meltwater from the glacier snout.

Question 17

What is the subsequent modification of an esker?

Answer 17

• Plant colonisation has reduced the mass movement but also biological weathering can take place.
• New eskers still exposed to physical weathering so may cause slumping of the sides (mass movement).

Question 18

What is a kame?

Answer 18

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

Question 19

Description of a kame?

Answer 19

a flat topped, steep sides hill of well sorted sand and gravel deposited by meltwater streams flowing into andice marginal lake or sea.

Question 20

How is a kame formed?

Answer 20

As meltwater streams enter ice-marginal lakes, they lose energy because they are entering a static body of water. This means they deposit the material they are depositing.

Question 21

What is the effect on climate change to Kames?

Answer 21

Warmer temperatures amounts to more melting equals more meltwater creating greater accumulation of outwatch material= more material to be deposited.

Question 22

What is a kame terrace?

Answer 22

A ridge of material running along the edge of the valley.

Question 23

An example of an kame terrace?

Answer 23

Kingsdale valley, Yorkshire Dales

Question 24

How is a kame terrace formed?

Answer 24

Supraglacial streams form at the sides of the glacier as a result of friction due to the exposed valley sides heating up faster than the glacier. These streams form small troughs at the sides of the glacier and pick up and carry lateral moraine. The material is later deposited by meltwater streams in post glaciation between a glacier and a valley wall.

Question 25

What is the effect on climate change to kame terraces?

Answer 25

Warmer temperatures = exposed valley sides heat up faster than the glacier ice= more melting along the edge of the glacier = more games exposed and of greater length.