Submergent landforms

Question 1

what is a submerged landform?

Answer 1

= rapid increase in global temperature-> melting of ice, decreasing water stored in glaciers -> increase volume in sea as molecules expand. SL rise= FLANDRIAN TRANSGRESSION means landforms are found below the water surface

Question 2

What is a fjord

Answer 2

= submerged glacial valley, up to 1km deep, 2-4km wide
-water sits in U-shaped valley formed by glaciation
-STEEP valley sides
-LONG with a ‘threshold’ at end (former terminal moraine)

Question 3

Example of a fjord

Answer 3

Signed fjord in Norway- used by submarines!

Question 4

How is a fjord formed?

Answer 4

1. valley is formed by plucking and abrasion of glacier
2. created by eustatic change after ice age where glacier melts and SL significantly rises
3. this fills the glacial valley with meltwater
   -coastal erosion at current SL widens fjords and forms notches (fairly insignificant as hard rock type slow to erode)
   -rivers and waterfalls in hanging valleys slowly build up fjords by depositing sediment
   -biological and freeze-thaw on sides create scree

Question 5

what is a ria?

Answer 5

= through lowland coastal areas rivers form floodplains and deltas made of alluvial deposits (silts and clay) due to flocculation

Question 6

example of a ria/ key features

Answer 6

South coast of Devon, Saltcombe and dartmouth
-flooded tributaries/exposed smooth valley sides
-sheltered coastal location used for shipping and settlements=> people develop defences to protect => alter coastal processes

Question 7

How is a ria formed?

Answer 7

1. SL rise floods floodplains -> shallow and wide bodies of water with one narrow old river section
2. due to large tidal range-> inlets and mudflats created for wildlife

Question 8

what is a shingle beach

Answer 8

=long beaches with large quantities of glacial sediment (greater than what’s provided by cliff erosion)

Question 9

example of a shingle beach/ dominant processes

Answer 9

Chesil peach/porlock bay
-LSD alters beach profile massively
-eustatic rise can flood beach in LY
-human interventions slow LSD

Question 10

how are shingles beaches formed?

Answer 10

1. sediment ‘rolled up’ from offshore as SL rise during Flandrian Transgression 10-6000 years ago=> causes wave action to push sediment onshore
2. SL increase further erodes cliffs-> pushing newley-created sediment along the glacially deposited sediment further inland