1.6 Fjords

Question 1

Sognefjorden Norway coast

Answer 1

Submergent coastline as result of eustatic sea level rise since LGM
Largest Fjord system in Norway
Dept of 800m below sea levels
Entrance at seaward end shallow (100m - 150m) due to rock bar threshold

Question 2

Eustatic sea level change post glacial

Answer 2

Sea level rise approx 125m over last 21k years

Meltwater pulse around 14k years ago, most ice melted by 6k years ago and sea level now only slowly rising

Question 3

Tectonic eustatic change

Answer 3

Faulting and folding of crust create s displacement of sea bed

Question 4

Fjords

Answer 4

Submerged u shaped valley that has been over deepened inland
Rock lil threshold exists at seaward entrance
Also found in Norway

Question 5

Rias

Answer 5

Drowned valley due to river erosion eg kings bridge estuary

Also found in wales (cork)

Question 6

Dalmatian coast

Answer 6

Example of tectonically formed submerged valleys (synclines) all exploited by rivers

Question 7

How is fjords formed

Answer 7

Pre glacial rivers exploits rocks, create valleys (v)
Ice sheets move and ground is frozen so rivers erode downwards
Glacial processes (abrasion) creates wide u shape valleys
U shape valleys become deepened
Ice advances further down valley not to coast, leaving rock lip
Rock lip breached by sea water, u shape valley flood
Sea levels continue to rise 125m higher leaving fjord