9: Rocky Coasts

Question 1

What are type A cliffs?

Answer 1

These are almost completely vertical cliffs that reflect the incoming waves back towards their source. This means that they are not subject to any significant erosion.

Question 2

What are type B and C cliffs?

Answer 2

These are shore platforms cliffs. Type B are ramp styled and Type C are sub-horizontal styled.

Question 3

What are type D cliffs?

Answer 3

Like type A except they are incised at the point in the cliff that where the sea level is. This is because these cliffs are composed of limestone

Question 4

What are type E and F cliffs?

Answer 4

These cliffs feature either a beach or talus deposit at the base of the cliff

Question 5

What are active cliffs?

Answer 5

Cliffs that are actively affected by sea processes

Question 6

What are inactive cliffs?

Answer 6

Cliffs that are not being affected by sea processes

Question 7

What are relic cliffs?

Answer 7

cliffs that used to be affected by sea level processes

Question 8

What are re-activated cliffs?

Answer 8

Cliffs that were active then relic and are now subject to active processes again

Question 9

Who was the first to realise wave cut platforms?

Answer 9

Darwin

Question 10

What did Dana observe

Answer 10

The effectiveness of erosion on shore platforms

Question 11

What did Davis observe?

Answer 11

How fluvial processes can erode volcanic islands and cause them to subside resulting in the obvious presence of coral reefs coming to the fore

Question 12

What did Davis name this process he identified?

Answer 12

Skeletonisation

Question 13

Describe dolerite

Answer 13

basaltic rock that forms hexagonal shape once it is eroded

Question 14

Describe basalt

Answer 14

form tall hexagonal landforms when eroded

Question 15

Describe Granite

Answer 15

forms rounded eroded boulders that are distinctively smooth

Question 16

Describe sandstone

Answer 16

forms sharp vertical cliffs

Question 17

Describe laterites

Answer 17

High iron concentration in rock strucutre

Question 18

Describe eolianite

Answer 18

fossil dune deposits that feature very clear horizontal banding and are prevalent around Australia

Question 19

Describe Calcarenite

Answer 19

sandy calcerous material

Question 20

Order basalt , limestone, granite, eolianite, chalk and shale rock in order from least to most resistant

Answer 20

Eolianite, chalk, shale rock, limestone, granite, basalt

Question 21

What are the 4 categories of processes affecting the erosion of cliffs?

Answer 21

Hydraulic
Mechanical
Physiochemical
Biological

Question 22

What are the 5 hydraulic processes of erosion and explain them?

Answer 22

Hydrostatic pressure
wave quarrying (waves lodging rocks from surface)
water hammer (shear force of water)
pneumatic (pocket of air trapped between air and rock)
cavitation (similar to pneumatic and exploits small rock cavities)

Question 23

What are the 2 mechanical processes of erosion?

Answer 23

Abrasion

Attrition

Question 24

What are the 3 physiochemical processes of erosion and explain them?

Answer 24

Wet/dry (water layer levelling - physiochemical processes of the water levelled on a rock surface e.g. dissolving)
Freeze/thaw weathering
Salt weathering (tafoni)

Question 25

Explain salt weathering (tafoni)?

Answer 25

Been described as honeycomb weathering as a result of the rock surface that is produced. Essentially salts crystallise in the rock and as they break away they take the rock with them

Question 26

What are the 2 biological processes of erosion and explain them?

Answer 26

Grazers (limpets erode at the surface of rocks)

Borers (certain organisms bore in to and erode from inside the rock)

Question 27

What happens to Type A cliffs at low, mid and high tides?

Answer 27

At all tides the process is the same because the cliff is completely vertical for a long vertical range. The waves are just reflected back out towards the sea

Question 28

What happens to Type B cliffs at low, mid and high tides

Answer 28

A ramped shore platform will always cause the incoming waves to trip up and break. The different tides will just affect how early the waves breakW

Question 29

What happens to Type C cliffs at low, mid and high tides

Answer 29

At the low tide the sea will not be able to overcome the platform and so will resemble what happens all the time for Type A cliffs. At mid tide it might be able to overcome the platform and so if it does it will only be a thin layer. At high tide there is a much greater chance it will be able to overcome the platform and so the waves will likely be able to cut away at the cliff

Question 30

What is whether the coast forms a cliff or a ramp determined by?

Answer 30

Local lithology and breaking wave force

Question 31

What is another way apart from erosion that coasts can be created?

Answer 31

Construction - tectonic uplift

Question 32

Give an example of somewhere (coastline) that is caused by tectonic uplift?

Answer 32

Huon Peninsula

Question 33

What is important to remember about how constructed coasts appear?

Answer 33

Eventhough they are constructed they can also be subject to later erosional processes

Question 34

The faster the erosion at the base, the faster the…

Answer 34

erosion overall