Coasts

Question 1

What are Constructive waves?

Answer 1

Create a gentle beach

Strong swash and a weak backwash - builds up the beach (deposition)

Question 2

What is long shore drift?

Answer 2

Transports sediment along the beach in a zig zag route

Question 3

Describe longshore drift

Answer 3

The wind blows towards the land at an angle, waves approach the beach at a angle, they break, swash carries the material at an angle.

Question 4

What is the formation of caves?

Answer 4

1. A large crack opened by hydraulic action
2. The crack grows into a cave by hydraulic action, the caves become larger.
3. The cave breaks through the headland forming a natural arch
4. The arch erodes and collapses
5. This leaves a tall rock stack
6. Stack erodes forming a stump

Question 5

How do we manage our coasts?

Answer 5

Through hard engineering and soft engineering

Question 6

Hard engineering

Answer 6

Building physical structures to stop waves eroding the land

Question 7

Soft engineering

Answer 7

Using nature to protect the coast, more environmentally friendly

Question 8

Types of soft engineering (3)

Answer 8

beach nourishment
sand dune regeneration
managed retreat

Question 9

Types of hard engineering (4)

Answer 9

sea walls
groynes
rock armour
gabions

Question 10

Sea Wall

Answer 10

A concrete wall to absorb the energy of a wave
creates a path for tourists
£2000 per meter, long lasting

Question 11

Groynes

Answer 11

Long wooden fences which stops longshore drift
£2000 per meter, stops transportation of sediment
Increases the risk of erosion along the beach

Question 12

Rock Amour

Answer 12

large boulders piled up at the foot of cliffs to absorb the waves energy
£300 per meter
looks natural

Question 13

Gabions

Answer 13

Rocks or boulders held in wire mesh cages; absorbs waves energy
£1000, not very strong, looks ugly

Question 14

Beach nourishment

Answer 14

Adding more sand to beaches in front of cliffs

Time consuming; sand has to come from somewhere

Question 15

Sand dune regeneration

Answer 15

Allowing sand dunes to build up around wooden structures

Absorbs wave energy; creates nee habitats

Question 16

Managed retreat

Answer 16

Abandoning existing sea defences and building new ones further inland
Some people will lose land/homes/business

Question 17

What are Destructive waves?

Answer 17

Create a steep beach

weak swash and a strong backwash - pulls sand and pebbles off the beach (erosion)