Coasts

Question 1

What is coastal erosion and why is it a concern?

Answer 1

Coastal erosion is the wearing away of land by the sea, causing loss of homes, businesses, and disruption to life and services.

Question 2

What is hydraulic action in coastal erosion?

Answer 2

It is the power of waves smashing into cliffs, forcing air into cracks which eventually breaks the rock apart.

Question 3

How does abrasion erode coastlines?

Answer 3

Fragments of rock, pebbles, and sand are hurled by waves against the cliff, wearing it down like sandpaper.

Question 4

What is attrition in coastal processes?

Answer 4

Rock fragments rub against each other underwater, gradually wearing down.

Question 5

How does solution contribute to coastal erosion?

Answer 5

Sea water chemically dissolves rocks like chalk and limestone.

Question 6

What is freeze-thaw weathering?

Answer 6

It occurs when water enters porous rocks, freezes, expands, and breaks the rock apart.

Question 7

How does chemical weathering work on coastlines?

Answer 7

Rainwater and seawater act as weak acids, breaking down rocks chemically.

Question 8

What is biological weathering?

Answer 8

Plants and animals break down rocks through physical or chemical means.

Question 9

What is suspension in coastal transportation?

Answer 9

Fine particles are carried within the water.

Question 10

How does solution play a role in transportation?

Answer 10

Rocks dissolve into the water and are carried as chemicals.

Question 11

What is traction in coastal transportation?

Answer 11

Large pebbles are rolled along the seabed by currents.

Question 12

What is saltation?

Answer 12

Pebbles are lifted and bounce along the seabed due to turbulence.

Question 13

How are waves formed?

Answer 13

Wind creates friction with the water surface, forming ripples that grow into waves.

Question 14

What is fetch in wave formation?

Answer 14

The distance a wave travels before reaching the shore.

Question 15

What is aspect in coastal geography?

Answer 15

The direction the coastline faces relative to incoming waves.

Question 16

What are constructive waves?

Answer 16

Low waves with strong swash that build up beaches with sand and pebbles.

Question 17

What are destructive waves?

Answer 17

Steep waves with strong backwash that erode beaches and carry material away.

Question 18

What is mass movement on coastlines?

Answer 18

The downward movement of rocks and loose material due to gravity exceeding the support.

Question 19

How is a wave cut platform formed?

Answer 19

Waves cause the most erosion at the foot of a cliff.
This forms a wave-cut notch, which enlarges as erosion continues.
The rock above the notch becomes unstable and eventually collapses.
Collapsed material is washed away and a new wave-cut notch starts to form.
Repeated collapsing results in the cliff retreating.
A wave-cut platform is the platform left behind as the cliff retreats.

Question 20

How do bays and headlands form generally?

Answer 20

When there are alternating bands of resistant and less resistant rock along a coast.

Question 21

How do bays form?

Answer 21

When less resistant rock is eroded faster, forming a bay with a gentle slope

Question 22

How do headlands form?

Answer 22

When softer rock is eroded inwards, hard rock sticks out into the sea.

Question 23

How do cracks form?

Answer 23

They are widened in the headland through an erosion all process of hydraulic action and abrasion.

Question 24

How do caves form?

Answer 24

Repeated erosion and enlargement of cracks cause caves to form.

Question 25

How do arches form?

Answer 25

When caves are eroded deeper and become larger eventually breaks through the headland to form an arch.

Question 26

How do stacks form?

Answer 26

When the base of the arch is continually widened by erosion until the roof becomes to heavy and collapses in the sea

Question 27

How is a stump formed?

Answer 27

When the stack is undercut at the base and collapses to form a stump.

Question 28

How do spits form?

Answer 28

When longshore drift transports sand and shingle past the sharp bends of a coastline and deposits it in the sea, winds and waves can curve the ends of the spit forming a recurved end. The area behind the spit is sheltered so material accumulates and plants can grow, over time these can form salt marshes and mudflats

Question 29

How do bars form?

Answer 29

When two headlands join together. The bay between two headlands gets cut off from the sea, which means a lagoon can form behind the bar.

Question 30

How do beaches form?

Answer 30

where material transported by the sea is dropped and accumulates in sheltered areas like bays

Question 31

How do sand dunes form?

Answer 31

When sand is deposited by longshore drift gets picked up by wind and move upwards.

Question 32

How do embryo dunes form?

Answer 32

When obstacles such as driftwood slow down wind speed, which cause sand to get accumulated in that area.