Coasts

Question 1

What is erosion

Answer 1

Erosion is the wearing away of the land by the sea and the material it carries

Question 2

What is transportation

Answer 2

Transportation is the movement of eroded materials by the sea

Question 3

What is deposition

Answer 3

Deposition is the laying down of materials carried by the sea

Question 4

What is a headland

Answer 4

A headland is a part of the coast that sticks out into the sea and ends with a cliff

Question 5

What is a bay

Answer 5

A bay is a wide curving inlet of the sea

Question 6

How are headlands and bays formed

Answer 6

Headlands are made up from hard rock which erodes slowly, making the headland stick out into the sea. Contrary to headlands, bays are made from soft rock that erodes faster, making the bay curve inwards

Question 7

Why can we usually find a beach at a bay

Answer 7

We can find a beach at a bay, because waves carry the eroded material from headlands into bays

Question 8

How is a stump formed

Answer 8

A stump is formed through the erosion of a headland. Firstly, a small cave is formed in a headland by hydraulic action. The cave is further eroded and deepened, forming an arch. The arch is eventually undercut, resulting in it falling due to the lack of support and gravity. A stack is left behind, which eventually collapses, leaving behind a stump

Question 9

What is a cliff

Answer 9

A steep slope overlooking the sea

Question 10

What is a cave

Answer 10

A cave is an underground feature formed by erosion at the base of a cliff

Question 11

What is an arch

Answer 11

An arch is a coastal feature made when waves erode through a headland

Question 12

What is a stack

Answer 12

A stack is a pillar of rock formed after an arch is undercut

Question 13

What is a stamp

Answer 13

A stamp is a rock remaining in the sea after a stack collapses

Question 14

How does hydraulic action erode the sea

Answer 14

With hydraulic action, water is forced into cracks in the rock, compressing the air inside. When the wave retreats, the air blasts out, forcing the rock apart and widening the crack

Question 15

How does corrasion erode the sea

Answer 15

With corrasion, loose rocks are thrown against the cliff by the waves. This wears away the cliff and causes bits of rock to fall off

Question 16

What’s another name for corrasion

Answer 16

Abrasion

Question 17

How does corrosion erode the sea

Answer 17

Corrosion is a type of chemical erosion. It occurs when the sea water dissolves material from the rock

Question 18

How does attrition erode

Answer 18

Attrition erodes the sediment rather than the land. Rocks and pebbles that fell of due to hydraulic action are swirled around by the waves, causing them to collide with other sediment. This turns them into smaller and rounder sediment

Question 19

What is a wave-cut notch

Answer 19

A wave-cut notch is an area undercut by erosion at the base of a cliff

Question 20

What is a wave-cut platform

Answer 20

A wave-cut platform is a flat surface at the base of a cliff caused by erosion

Question 21

How does a cliff retreat due to erosion

Answer 21

At the base of the cliff, hydraulic action forms a wave-cut notch. The size of it is determined by the distance between the high tide and the low tide. The wave-cut notch creates an on overhang, which eventually falls down due to gravity. As broken rocks are made smaller by attrition, they make the wave-cut platform smooth by corrasion. The process is repeated many times, causing the cliff to retreat and the wave cut platform to get wider

Question 22

What is longshore drift

Answer 22

Longshore drift is the movement of materials along the coast by waves that approach the sea at an angle

Question 23

Describe the process of longshore drift

Answer 23

Waves carrying materials move up the beach at angle due to the direction of the wind. The wave then moves straight down the beach because of the pull of gravity. This results in the materials moving in a zig-zag pattern

Question 24

What is a groyne and what does it do

Answer 24

A groyne is a wall built perpendicular to the coast that prevents erosion and extends the land. It does so by stopping longshore drift and making sand pile up on the end of the groyne.

Question 25

Why do hotels build groynes

Answer 25

Hotels build groynes as they block longshore drift, resulting in sand piling at the end of the groyne. This extends the land, allowing the hotel owners to build more

Question 26

How do groynes affect the land on the opposite side of the groyne

Answer 26

Groynes block longshore drift and the material it carries. This results in all the carried material staying on the one side of the groyne. The lack of material coming to the other side causes the land to erode

Question 27

What are parallel wave-breakers

Answer 27

Parallel wave-breakers are large rocks in the sea that force waves to break before they hit the coast. They absorb the energy of the waves and encourage deposition

Question 28

What are the advantages/disadvantages of parallel wave-breakers

Answer 28

Advantages: effective, do not spoil the beach
Disadvantages: Expensive, hard to mantain

Question 29

What are rip-raps/ rock armour

Answer 29

Rip-raps are large rocks placed on the coast to prevent erosion by absorbing the energy of the waves

Question 30

What are the advantages/disadvantages of rip-raps

Answer 30

Advantages: Cheap, uses natural materials
Disadvantages: Allows some erosion, can be moved by large rocks

Question 31

What is a seawall

Answer 31

A seawall is a wall build along the coast that prevents erosion by reflecting the waves and absorbing their energy

Question 32

What are the advantages/disadvantages of a seawall

Answer 32

Advantages: Very effective
Disadvantages: Ugly, very expensive