7. Coasts

Question 1

abraison

Answer 1

whenrocks are thrown against the side of the river

Question 2

arch

Answer 2

a coastal feature created by the erosion of back-to back caves

Question 3

attrition

Answer 3

when rocks bash against eachother and break down, eventually getting really small

Question 4

backwash

Answer 4

the waves that are reatreating

Question 5

bay

Answer 5

an area of sea between two headlands

Question 6

beach

Answer 6

material which the sea deposits on the coast

Question 7

corrosion/solution

Answer 7

a chemical process involving the dissolving away of sediment

Question 8

erosion

Answer 8

the wearing away of material

Question 9

estuary

Answer 9

the final section of a river, where freshwater and saltwater mix

Question 10

headland

Answer 10

a promontory of resistant rock which juts out in the sea

Question 11

hydraulic action

Answer 11

when the water bashes against the side of a river and rocks break off

Question 12

longshore drift

Answer 12

the movement of sand and pebbles along a beach by wave action

Question 13

saltation

Answer 13

the transport of sediment hopping on the sea floor

Question 14

spit

Answer 14

an extended beach which grows by deposition across a bay or river mouth

Question 15

suspension

Answer 15

a method of transporting very fine (small) sediment in a river

Question 16

swash

Answer 16

wave going towards the coast

Question 17

traction

Answer 17

the transport of boulders in a rolling motion in water

Question 18

weathering

Answer 18

the breaking down of a material

Question 19

describe how headlands and bays are made

Answer 19

headlands are made of hard rock & bays are made of soft rock
*as the soft rock is weaker, then it erodes more easily and then a bay is formed

Question 20

describe wave cut platforms

Answer 20

*the area between the high tide and the low tide is the wave cut notch
*due to hydraulic action and abrasion, it creates a dent in the cliff and that is the wave-cut platform

Question 21

describe how CASS (caves, arches, stacks and stumps) are made

Answer 21

It starts with a fault in the cliff.

1. Waves attack the fault by hydraulic action and abrasion.
2. This makes a cave. A blowhole may appear on top of the cliff due to upward erosion by waves hitting the roof of the cave.
3. Hydraulic action and abrasion widen and deepen the cave and eventually cut through the cliff to form an arch.
4. Due to a lack of support, the area above the arch collapses, creating a stack.
5. Weathering and erosion turn the stack into a stump.

Question 22

describe longshore drift

Answer 22

The swash moves up the beach at the angle of the prevailing wind and then down at a 90° angle until it reaches a barrier (if there is one)
*This is how rocks and pebbles move up a beach.

Question 23

describe the features of a constructive wave

Answer 23

*They have a large swash meaning they carry material far up the beach.
*Frequency of 6-9 waves per minute.
*Smaller and shorter waves
*Weak backwash that carries little sediment

Question 24

describe the features of a destructive wave

Answer 24

*Created in storm conditions
*Have a strong backwash which erodes the coast
*Wave has travelled over a long fetch (how far it has travelled) - big
*Frequency of 11-15 per minute
*Larger and bigger waves
*Weak swash that moves little sediment up the beach

Question 25

describe how a spit is created

Answer 25

1. Longshore Drift (LSD) moves material up the coastline.
2. The coastline suddenly changes direction and deposition continues into shallow, sheltered areas and material continues to be deposited.
3. A spit is formed from this deposited material.
4. Over time, the spit turns into a curve due to the wind.
   (5.) Sometimes a salt marsh will appear on the sheltered side of the spit.

Question 26

give examples of soft engineering (min 2)

Answer 26

*Beach nourishment: Sand is added to a beach to flatten it out. It is cheap but does not last for very long.
*Managed Retreat: lets the areas of low value get flooded and protects the important areas further down the coast.
*Cliff Stabilisation: Cliffs are covered in vegetation planted there to help make them more stable and erosion resistant.
*Do nothing: The cheapest and most eco-friendly way. Lets nature erode the coast how it is meant to.

Question 27

give examples of hard engineering (min 2)

Answer 27

*Sea Wall: Put at the base of a cliff to reflect the waves energy. Very expensive - £10,000 per km. Ugly but effective at protecting areas from flooding.
*Gabions: Cages of wire with rocks to absorb the energy from the waves. Effective and cheap, but ugly.
*Groynes: Wood or rock structures placed at right angles to the beach to trap sediment. Helps build up the beach and protect the cliff from erosion. results in areas further down the coast being starved of beach material meaning more erosion.
*Rip-Rap (rock armour): Large rocks put at the bottom of the cliff to absorb the wave’s energy. Effective at dispersing the waves energy and are cheap, but are ugly.

Question 28

what is CASS

Answer 28

Cave
Arch
Stack
Stump