Recap 1 Coasts

Question 1

What is meant by sub-aerial processes?

Answer 1

Weathering: the chemical, biological and mechanical breakdown of rocks into smaller fragments and new minerals in situ.
Mass movement: landslides, slump and rock falls, all of which move material downslope under the influence of gravity.
Surface runoff: water, usually during heavy rain, flowing down the cliff face and causing erosion of it.

These processes are likely to be more important when cliffs are made of less-resistant rocks such as shale, clay or mudstone.

Question 2

What do coasts represent a boundary zone of?

Answer 2

Where land and sea meet, and where both marine and terrestrial processes operate and interact.

Question 3

What is the littoral zone?

Answer 3

The wider coastal zone including adjacent land areas and shallow parts of the sea just offshore.

Question 4

Outline the four sub zones of the littoral zone

Answer 4

Backshore, foreshore, nearshore and offshore

Question 5

Why is the littoral zone one of dynamic equilibrium?

Answer 5

Due to the wide range of natural processes that interact within it:
There are inputs of sediments from the sea and currents from rivers flowing off the land.
Weathering and mass movement occur on the backshore.
Constructive and destructive waves occur on the foreshore and nearshore, causing deposition and erosion.
The tidal range affects all parts by determining where wave action takes place.
Offshore currents and longshore drift may move sediments some distance along a coast.

Question 6

How can human activities interfere with natural processes?

Answer 6

Dredging of rivers to make them deeper for shipping
Dredging of offshore areas to get sand and gravel for construction .
The building of coastal defences against erosion and flooding.

Question 7

When can rapid change at coasts take place?

Answer 7

When there is increased energy in the natural processes or when the impacts of human activities are not carefully considered.

Question 8

Coasts can be classified in a variety of ways according to different physical processes. Give the difference between primary and secondary coasts.

Answer 8

A

Question 9

Give the difference between emergent and submergent coasts.

Answer 9

A

Question 10

Give the difference between microtidal, mesotidal and macrotidal coasts

Answer 10

A

Question 11

Give the difference between low energy and high energy coasts

Answer 11

A

Question 12

How does geology affect the coastal classification?

Answer 12

A

Question 13

What are the two main types of coasts?

Answer 13

A

Question 14

Outline the differences between rocky coastlines and coastal plains

Answer 14

A

Question 15

There are two main cliff profile types on rocky coastlines. What are the cliffs like where marine erosion by wave action dominates?

Answer 15

A

Question 16

Cliffs which are not actively eroded at their base by waves have shallower, curved profiles and lower relief. On these cliffs the sub-aerial processes of surface runoff erosion and mass movement (landslides) slowly move rock and sediment downslope. However, why is this material not removed?

Answer 16

A

Question 17

Give examples of factors that influence the ‘hardness’ of rocks

Answer 17

A

Question 18

Define unconsolidated sediment

Answer 18

A

Question 19

What are coastal plains?

Answer 19

A

Question 20

How do coastal plains form?

Answer 20

A

Question 21

In many locations coastal plains are maintained in a state of dynamic equilibrium, why?

Answer 21

A

Question 22

Overall, coastal plains are often a low-energy environment, usually lacking very large and powerful waves except on rare occasions. Give an example of when.

Answer 22

A