coasts

Question 1

features of destructive waves

Answer 1

high frequency
high
steep

Question 2

features of constructive waves

Answer 2

low frequency
low
long

Question 3

destructive waves

Answer 3

backwash is more powerful than swash so material is removed

Question 4

how do constructive waves build beaches

Answer 4

swash is more powerful than backwash so material is deposited

Question 5

mechanical weathering

Answer 5

breakdown of rock without changing it’s chemical composition
e.g. freeze thaw weathering

Question 6

chemical weathering

Answer 6

breakdown of rock by changing its chemical composition
e.g. carbonation weathering

Question 7

process of freeze-thaw weathering (mechanical)

Answer 7

1. water enters rock that has cracks
2. it freezes overnight which makes the crack bigger
3. in the day, it melts and more water fills into the crack
4. the water freezes again making the crack bigger
5. this repeats until the rock breaks

Question 8

process of chemical weathering

Answer 8

1. rainwater has carbon dioxide dissolved in it —> makes it a weak carbonic acid
2. carbonic acid reacts with limestone —> so rocks break

Question 9

define hydraulic action

Answer 9

waves crash against rock and pushes air into cracks —> the force of this causes bits of rock to break off

Question 10

define abrasion

Answer 10

loose rocks (sediment) are thrown against the cliff by waves. this wears away at the cliff and chips bits of rock

Question 11

define attrition

Answer 11

eroded particles in water collide and knock into each other to become smaller and more rounded

Question 12

define solution

Answer 12

seawater dissolves material from the rock

Question 13

what is mass movement

Answer 13

shifting of rocks and loose material down a slope e.g. a cliff

Question 14

why does mass movement happen

Answer 14

it happens when the force of gravity acting on a slope is greater than the force supporting it

Question 15

define slide

Answer 15

material shifts in a straight line along a slide plane

Question 16

define slump

Answer 16

material rotates along a curved slip plane

Question 17

define rockfall

Answer 17

material breaks up and falls down a slope

Question 18

3 types of mass movement

Answer 18

slides
slumps
rockfall

Question 19

describe longshore drift

Answer 19

1. waves follow the direction of the prevailing wind and approach beach at an angle
2. swash carries material up the beach at the same angle
3. backwash carries material straight back down the beach at right angles
4. overtime, material moves along beach in zigzag pattern

Question 20

define deposition

Answer 20

when water loses energy and drops the material it is carrying

Question 21

when does deposition on an area of a coast increase?

Answer 21

there’s lots of erosion elsewhere (so more material is available)

Question 22

how do headlands and bays form

Answer 22

1. alternating bands of resistant and less resistant rock
2. less resistant rock is eroded faster, forming a bay
3. resistant rock erode more slowly and forms a headland which sticks out

forms along discordant coastlines

Question 23

how is a wave cut platform formed

Answer 23

1. sea attacks base of cliff forming a wave cut notch
2. repeated erosion causes rock above notch to become unstable and it eventually collapses
3. collapsed material is washed away and a new wave cut notch starts to form
4. repeats, the cliff retreats, leaving a wave cut platform

Question 24

how do caves, arches, stacks and stumps form

Answer 24

1. resistant rock headland have cracks
2. abrasion and hydraulic action widens the cracks
3. repeated erosion of cracks causes cave to form
4. continued erosion deepens the cave until it breaks through the headland to form an arch
5. arch is eroded until the roof collapses leaving a stack
6. stack eventually collapses leaving a stump

Question 25

example of hard rock and soft rock

Answer 25

hard rock - granite soft rock - sandstone

Question 26

define discordant coastlines

Answer 26

alternating bands of hard and soft rock at right angles to the coast

Question 27

define concordant coastline

Answer 27

alternating hands of hard and soft rock that are parallel to the coast

Question 28

how are sand beaches formed

Answer 28

constructive waves build up beaches as they have a strong swash and a weak backwash form in sheltered areas like bays where waves have limited energy

Question 29

how are shingle beaches formed

Answer 29

high energy waves and are steep and narrow sand particles are washed away but larger shingle left behind

Question 30

what is a bar

Answer 30

a bar forms when a spit joins 2 headlands together

Question 31

how is a bar formed

Answer 31

1. a bar forms when a spit joins 2 headlands together 2. bay between headlands gets cut off from the sea 3. lagoon forms behind the bar

Question 32

what feature lays behind a bar

Answer 32

lagoon

Question 33

why do spits have a hooked or recurved end

Answer 33

strong winds and waves can change the direction of it

Question 34

what are spits

Answer 34

long narrow ridges of sand and shingle stretching out from the coast

Question 35

how is a spit formed

Answer 35

1. longshore drift transports sand and shingle past the bend and deposits it in the sea 2. strong winds and waves can curve the end of a spit (forming recurved end) 3. area behind the spit is sheltered from waves so material accumulates and plants are able to grow 4. overtime, the sheltered area can become a mud flat or a salt marsh

Question 36

what feature lies behind a spit

Answer 36

salt marsh and mud flats

Question 37

what 3 features are formed by deposition

Answer 37

spits, bars, sand dunes

Question 38

how are sand dunes formed

Answer 38

1. Sand is blown over an obstacle like a dead animal or a rock by wind 2. When the sand comes into contact with the obstacle, the wind slows down and the sand is deposited 3. This forms an embryo dune 4. Over time, plants like Marram Grass stabilise the sand and encourage more sand to accumulate there 5. The dunes steadily get bigger as you move back from the coast because the amount of vegetation increases. 6. d’une slacks can form in hollows between dunes

Question 39

what grass grows on sand dunes and holds them in place

Answer 39

marram grass

Question 40

coast

Answer 40

A part of land that joins the sea.

Question 41

what causes waves to form

Answer 41

Wind blowing over the sea

Question 42

What does the size and strength of waves depend on?

Answer 42

• How strong the wind is • How long it blows for • How far it travels

Question 43

swash

Answer 43

Water rushing up the beach

Question 44

backwash

Answer 44

Water draining back down the beach

Question 45

fetch

Answer 45

The distance a wave has travelled

Question 46

constructive waves

Answer 46

Waves that have a very strong swash and a weak backwash They build up the beach

Question 47

marine processes

Answer 47

The base of cliffs being eroded by hydraulic action and abrasion

Question 48

waves associated with coastal erosion

Answer 48

Destructive waves

Question 49

erosion

Answer 49

Wearing away of rocks by water, weather or ice

Question 50

4 types of erosion

Answer 50

1. Hydraulic action 2. Abrasion 3. Attrition 4. Solution

Question 51

How is sediment transported along the coastline?

Answer 51

longshore drift

Question 52

define landform

Answer 52

A feature in the landscape that has been formed by erosion, transportation and/ or deposition.

Question 53

What factors influence the landforms found along a coastline?

Answer 53

Hard rock (resistant rock) - does not erode easily - likely to find headlands Soft rock (less resistant rock) - erodes easily - more likely to be a bay

Question 54

coastal landforms that result from erosion

Answer 54

1. Headlands and bays 2. Cliffs 3. Wave cut platforms 4. Caves, arches, stacks and stumps

Question 55

coastal landforms that form as a result of deposition

Answer 55

1. Beaches 2 Sand dunes 3. Spits 4. Bars