Coasts

Question 1

What is a coast?

Answer 1

When the land meets the sea

Question 2

What is a headland?

Answer 2

Land sticks out into the sea

Question 3

What is a bay?

Answer 3

Shoreline shaped as a U

Question 4

What is a spit?

Answer 4

Ridge of sand that goes out towards the sea

Question 5

What is a lagoon?

Answer 5

A shallow body of water that is

Question 6

What is a tombolo?

Answer 6

A spit connecting the mainland to an island

Question 7

What is a bar?

Answer 7

A ridge of sand connecting two headlands

Question 8

What are salt marshes?

Answer 8

Coastal wetlands that are flooded and drained by salt water

Question 9

What is a beach?

Answer 9

A build up of sand and sediments

Question 10

How is a wave developed?

Answer 10

Friction with the surface of the water causes ripples to form which develops into waves

Question 11

What is a fetch?

Answer 11

The distance of a wave (longer the fetch, stronger the wave)

Question 12

What is backwash?

Answer 12

When the waves wash back down to the sea in a straight line

Question 13

What is swash?

Answer 13

When the waves come up to the beach at an angle

Question 14

What happens when waves hit a coast?

Answer 14

1. Waves in circular orbit in open water
2. Friction with the seabed changes the circular orbit motion
3. Top of the waves move faster and it changes from circular to elliptical orbit
4. When the wave reaches the coast it begins to break
5. Water from a previous wave returns

Question 15

What are the two types of waves?

Answer 15

Constructive and destructive

Question 16

Give characteristics of constructive waves

Answer 16

• Low waves
• Waves crest apart
• Spill onto the beach
• Powerful swash
• Weaker backwash
• Deposition - creates beach

Question 17

Give characteristics of destructive waves

Answer 17

• High waves
• Waves crest close
• Plunges onto beach
• Weaker swash
• Strong backwash
• Erosion - wears away the beach

Question 18

What is weathering?

Answer 18

The breaking down of rocks in situ (in place)

Question 19

What is mass movement?

Answer 19

The downward movement or sliding of material under the influence of gravity

Question 20

What are the three types of weathering?

Answer 20

• Mechanical (physical) weathering
• Chemical weathering
• Biological weathering

Question 21

What is mechanical weathering?

Answer 21

The breakup of rocks. Piles of rock fragments are found at the bottom of the cliff (called scree)

Question 22

What is chemical weathering?

Answer 22

Caused by chemical changes e.g. acid rain which dissolves certain types of rocks and minerals

Question 23

What is biological weathering?

Answer 23

Due to the actions of flora and fauna. Plant roots can grow in the cracks of rocks. Animals such as rabbits can burrow into weak rocks such as sand

Question 24

What is freeze thaw?

Answer 24

A type of mechanical weathering
1. Water collects in holes/cracks in the rock
2. The water turns into ice and expands, this makes the crack bigger
3. When the temperature rises and ice thaws, the water will seep deeper into the rock
4. Repeated freezing and thawing, fragments of rock will break off

Question 25

What is salt weathering?

Answer 25

A type of mechanical weathering
1. Seawater contains salt, when the water evaporates it leaves behind salt crystals in cracks
2. The salt crystals grow and expand making the crack bigger
3. This puts pressure on the rocks and flakes and may eventually break off

Question 26

What is carbonation?

Answer 26

A type of chemical weathering
1. Rainwater absorbs CO2 from the air and becomes slightly acidic
2. Contacts with alkaline rocks such as chalk and limestone
3. This produces a chemical reaction causing the rocks to slowly dissolve

Question 27

What are types of mass movement?

Answer 27

• Rockfall - fragments of rock break from the cliff face due to freeze thaw weathering
• Landslide - blocks of rock slide downhill
• Mudflow - Saturated soil with water and weak rocks flow down a slope
• Rotational slip - slump of saturated soil with water and weak rock along a curved surface

Question 28

What is longshore drift?

Answer 28

When material is transported along the coast

Question 29

What is transportation?

Answer 29

Movement of material e.g. pebble, sediment and rocks

Question 30

What is deposition?

Answer 30

When sediment is dropped by waves

Question 31

What is erosion?

Answer 31

The wearing away of rocks by the sea

Question 32

What are the coastal erosion processes?

Answer 32

HASS
* Hydraulic power
* Abrasion
* Attrition
* Solution

Question 33

What is hydraulic power?

Answer 33

The sheer force of the wave crashing against the cliff causes parts to break away
The waves also compress air in cracks in the rock ‘blasting away’ small fragments
The explosive force of trapped air operating in the crack is known as cavitation

Question 34

What is abrasion?

Answer 34

Waves pick up sand and pebbles (especially during storms) and hurl them against the cliff creating a sandblasting effect

Question 35

What is attrition?

Answer 35

Rock fragments carried by the sea knock against one another causing them to become smaller and more rounded

Question 36

What is solution?

Answer 36

The dissolving of soluble chemicals in rocks e.g. limestone