Coasts

Question 1

Why is the coast a multi-use area?

Answer 1

It provides economic, environmental and recreational opportunities.

Question 2

Why are coral reefs important?

Answer 2

• homes for sea creatures
• bio-diverse - some species can only survive there
• nutrient-rich water
• main source of energy for reef wilflife
• shelter
• tourist attraction
• coastal defence
• scientific research

Question 3

What are the threats to coral reefs?

Answer 3

• tourists damaging the area
• increase in sediment levels
• explosive fishing
• development
• global warming
• pollution

Question 4

Name 5 types of erosion.

Answer 4

1) Wetting/drying
2) Abrasion
3) Hydrolic action
4) Corrosion
5) Attrition

Question 5

Name 4 types of weathering.

Answer 5

1) Freeze-thaw
2) Onion-skin
3) Biological
4) Chemical

Question 6

What is wetting/drying?

Answer 6

1) Soft rocks get wet and expand
2) Contract when dry
3) Weakens the rock over time

Question 7

What is abrasion?

Answer 7

Caused by rocks in the sea hitting cliffs.

Question 8

What is hydrolic action?

Answer 8

Caused by the force of waves.

Question 9

What is corrosion?

Answer 9

Sea water dissolves soluble material along the rock face.

Question 10

What is attrition?

Answer 10

Rocks and boulders hit each other in the sea and break apart.

Question 11

What is freeze-thaw weathering?

Answer 11

1) Water gets into cracks
2) The water freezes and expands
3) The cracks get bigger and the rocks break

Question 12

What is onion-skin weathering?

Answer 12

Rocks being constantly heated and cooled, causing the surface to peel away.

Question 13

What is biological weathering?

Answer 13

Weathering caused by plants or animals, e.g. tree roots.

Question 14

What is chemical weathering?

Answer 14

Weathering caused by chemicals, e.g. acid rain.

Question 15

What is a consructive wave?

Answer 15

• long, low waves
• strong swash, weak back wash
• allows the beach to build up
• limited errosion

Question 16

What is a destructive wave?

Answer 16

• short, steep waves
• strong back wash, weaker swash
• eroded material removed by waves

Question 17

How are bays and headlands formed?

Answer 17

Different rocks erode at different speeds. A strip of soft rock with hard rock either side will erode so that a bay is formed where the soft rock is eroded quickly and headlands where the hard rock erodes slowly.

Question 18

What is cliff slumping?

Answer 18

• Soft rock is eroded by waves as the base of the cliff to form a wave-cut notch.
• Clay becomes saturated and forms slip planes.
• The weight of the saturated cliff causes it to slump.

Question 19

How are spits formed?

Answer 19

When the energy of the river meets the energy of the sea the material it was carrying is deposited.

Question 20

What are swash-aligned beaches?

Answer 20

• waves approach at 90 degrees to the beach

- have a smooth profile

Question 21

What are drift-aligned beaches?

Answer 21

• waves approach at an angle

- much more common

Question 22

How is sediment transported along the cost?

Answer 22

Long-shore drift.

Question 23

What is a tombolo?

Answer 23

When a spit connects the mainland to an island, e.g. chesil beach.

Question 24

What is a bar?

Answer 24

A bar connects a mainland to another mainland.

Question 25

What are the DEFRA options?

Answer 25

• Hold the line: maintain the existing coastline by building defences.
• Advance the line: build new defences in front of existing ones.
• Managed realignment: Allow the land to floor and construct a new line of defence inland.
• No intervention: allow natural processes to shape the land.

Question 26

What is beach replenishment?

Answer 26

When sand and gravel are taken from the sea bed and moved to areas which have less sediment to act as a natural defence.