Coastal change

Question 1

Give 5 uses of coasts.

Answer 1

Habitats, Residential, Harbour (fishing), Historical Defensive sites, Tourism + Leisure, Transport, Economic (shipping)

Question 2

What features does a Hard rock coast have?

Answer 2

Shape: High, Steep, Rugged
Face: Bare, No vegetation, Little loose rock
Foot: Boulders and rocks fallen from cliff

Question 3

What features does a Soft rock coast have?

Answer 3

Shape: Less rugged and less steep, maybe high
Face: Piles of mud and clay slipped down face
Foot: Few rocks, Some sand and mud

Question 4

What is the most and least resistant type of rock?

Answer 4

Clay = least resistant
Granite = most resistant

Question 5

Describe a discordant coastline.

Answer 5

Two headlands and a bay in the middle, both hard and soft rock, right angles to sea

Question 6

Describe a concordant coastline.

Answer 6

Both hard and soft rock, parallel to sea, rock erodes at different rates, a cove forms.

Question 7

Name the four types of erosion.

Answer 7

A - Attrition
S - Solution (corrosion)
H - Hydraulic Action
A - Abrasion (corrasion)

Question 8

What is weathering?

Answer 8

The break down and gradual wearing away of rocks by Ice (Physical), Water/Liquids (Chemical solution) , Tree roots/Animals (Biological)

Question 9

Define attrition.

Answer 9

Erosion through pebbles and rocks wearing away as they crash against each other

Question 10

Define solution (corrosion).

Answer 10

Erosion when the water itself is slightly acidic and dissolves minerals like calcium carbonate in chalk and limestone rocks.

Question 11

Define Hydraulic Action.

Answer 11

Erosion when the force of waves traps air in cracks creating pressure and pieces of rock break off.

Question 12

Define Abrasion (corrasion)

Answer 12

Erosion when the waves throw pebbles and rocks against the cliffs wearing them away.

Question 13

What is biological weathering?

Answer 13

A plant grows in a crack in rock and its roots push through the rock breaking it up.

Question 14

What is chemical weathering?

Answer 14

Acid rain falls on rock dissolving it.

Question 15

What is freeze thaw weathering?

Answer 15

Rain fills a crack in rock which turn to ice and expands breaking the rock into two pieces.

Question 16

What is onion skin weathering?

Answer 16

Rock expands during hot day and contracts during cold night allowing the outer layer to have cracks and weaknesses.

Question 17

Describe the process of formation of a cave, arch, stack and stump.

Answer 17

Erosion (solution, hydraulic action and abrasion) form cracks in a headland leading to a cave and then an arch. More erosion and weathering from above means the top piece has no support and falls leaving a stack. Erosion from the bottom forms an undercut and the stack falls over leaving a stump.

Question 18

What 3 affects to waves have on the coast?

Answer 18

Erosion, transport and deposit of eroded material

Question 19

What is swash and backwash?

Answer 19

Swash = Water washing UP the beach
Backwash = Water running BACK DOWN beach

Question 20

Describe constructive and destructive waves.

Answer 20

Constructive = strong swash, weak backwash, construct beach by depositing material
Destructive = weak swash, strong backwash. destroy beach by eroding material away

Question 21

What is long-shore drift?

Answer 21

Process of deposition and transportation (movement of material)

Question 22

What affect does the direction of prevailing wind have on long-shore drift?

Answer 22

It determines the direction of long-shore drift.

Question 23

Describe the process of cliff retreat.

Answer 23

Cliff is undercut by waves and the eroded material forms a wave-cut platform. This allows a high tide further eroding the cliff causing it to ‘retreat’.

Question 24

Describe the process of cliff slumping.

Answer 24

Bottom of cliff is eroded by waves making the cliff slope steeper. This makes it easier for rock to slide down. Saturation due to rain lubricates the rock and makes it heavier. The cliff can slide downwards in a rotational manner causing a rotational cliff slump.

Question 25

Describe the process of spit formation.

Answer 25

Longshore drift deposits beach material on a headland, this eventually builds up forming a spit. A change in prevailing wind direction can cause the deposition of sediment to curve round.

Question 26

Why could a salt marsh form behind a spit?

Answer 26

The curving of a spit could mean the water behind it becomes stagnant due to no fresh flow of water getting there allowing a salt marsh to form.