1.6(Spec2) - Submergent Coastlines + Sognefjorden

Question 1

How much has sea level risen since Last Glacial Maximum?

Answer 1

• 125 m
• meltwater pulse around 14,000 years ago
• most melted around 6000 years ago

Question 2

What is a fjord?

Answer 2

Submerged valley created by glaciers
- glaciers push sediment to side/ bottom of valley
- U shaped valley
- glacial till is left at bottom
- drowned by eustatic sea level rise

Question 3

What are Rias?

Answer 3

• unglaciated river valleys
• are created by river erosional processes
• drowned by eustatic sea level rise
• in areas not covered by ice in LGM

Question 4

What sort of coastline is Sognefjorden?

Answer 4

• Submergent
  
  • due to eustatic SLR since LGM

Question 5

How large is Sognefjorden?

Answer 5

• 200km inland
  
  • largest fjord system in Norway

Question 6

How deep is Sognefjorden?

Answer 6

• 800m below sea level
• entrance is shallower at 100-150m due to rock bar

Question 7

What is the rock bar at Sognefjorden?

Answer 7

• result of deposition of glacial till when Sognefjorden was a glacier

Question 8

What has determined the path of Sognefjorden?

Answer 8

• fracture systems in bedrock
  
  • exploited by glaciers and then rivers

Question 9

How can eustatic SL change?

Answer 9

• tectonics
• post glacial melt

Question 10

How do tectonics change sea level?

Answer 10

• faulting and folding of crust can displace seabed
  
  • can result in local sea level rise or fall

Question 11

How is sea level changed by post glacial events?

Answer 11

• meltwater flows into rivers and out to sea
  
  • eustatic sea level change
• melting of glaciers results in isostatic rebound
  
  • isostatic sea level change