Coast

Question 1

Abrasion

Answer 1

When pebbles are picked by the waves and thrown against the cliff this create a sand paper effect

Question 2

Hydraulic action

Answer 2

Force of the wave hit the rock, the air is trapped by the wave in the crock and cracks it further due to the hydraulic pressure

Question 3

Attrition

Answer 3

When rocks that the river is carrying knock against each other they break apart to become smaller and more rounded

Question 4

Solution/corrosion

Answer 4

Where the rock is put into the solution by weak acid

Question 5

Characteristics of destructive waves

Answer 5

High wave height

Beach gradient steep

Plunge forward

Smash is weak

Rotation of water causes strong backwash

Erodes beaches

Question 6

Constructive wave characteristics

Answer 6

Low wave height

Beach gradient is gentle

Spill forward gently

Creates a strong swath

Water drains through beach material

Backwash is weak

Build up beaches

Question 7

Key factor that affect the coast

Answer 7

Geology- hard rock types are less likely to erode

Fetch of the wave and the strength of the wind. Powerful winds and a long fetch create the most damaging erosive waves

The angle of the slope- steep slopes erode more violently and frequently

Weather conditions- freezing temperatures and heavy rain increases weathering and rate of erosion

Amount of vegetation- presence of vegetation helps stabilise slope but also increase occurrence of the biological weathering

The amount of human interference- if there are no man-made structure(eg sea wall) to protect the coast then the coast is more vulnerable to attack.

Question 8

Explain how longshore drift

Answer 8

1. Prevailing winds pushes the wave at an angle eh oh then picks up sediment they come in at an angle because of the wind direction.
2. Smash moves up the beach at the angle
3. the wave that called backwash pulls the sediment back down straight to the beach,
4. the process then gradually moving sediment along the beach in a zigzag motion and is called longshore drift

Question 9

Coastal deposition

Answer 9

It where the material that is being transported is dropped by a constructive wave, this happens when waves have less energy, when smash is stronger than backwash

Question 10

Wave cut platform

Answer 10

Wave cut platform is formed by the sea attacking the cliff face though different type of erosion

Abrasion is where the cliff are worn down from destructive waves and throwing of the material in the wave

Hydraulic action occur when the when enter the cracks within the cliff at the high tide mark compressing the air within resulting in expansion of the crack as the wave retreats

This then has the effect of creating a notch which slowly become larger and larger forming a small cave

As erosion continues to occur the weight of the cliff eventually can’t support itself and collapse as a result with the material being deposited and then carried out the the sea through repetition of these processes, a wave cut platform is formed

Question 11

Formation of cave

Answer 11

Crack in the rock erode through abrasion

Cave occur when the wave force their way into the crack in the cliff face.The water contain sand and other materials grind away at the rock until the cracks become a cave . This is called hydraulic action and abrasion are the main Erosion

Question 12

Formation of arch

Answer 12

If the cave is formed in a headland. It may eventually break through to the other side forming an arch

Question 13

Formation of stack

Answer 13

The arch will continue to be eroded(attrition) and will gradually become bigger until it can no longer support the top of the arch. When the arch collapse , it leaves the head land on one side and a stack( a tall column rock) on the other

Question 14

Formation of stump

Answer 14

The stack will be attacked at the base in the same way that a wave-cut notch is formed. This weakens the structure and it will eventually collapse to form a stump

Question 15

Discordant coastline

Answer 15

Have bays and headlands as there are alternating hard and soft rock

Question 16

Concord at coastline

Answer 16

Have less bay and lead lands as there are made up of the same type of rock

Question 17

Formation Bay and headlands

Answer 17

Headland and bays are formed at the discordant coastline.

The bands of soft rock are less resistant to erosion, such as sand and clay

Therefore, they erode more quickly than the hard rock which is more resistant such as limestone

Waves are able to erode the soft rock more rapidly and form bays. Bay form beaches and are covered by layers of loosely consolidated sand ,slit and clay.
Bays are made of rock that are easily eroded

Erosion by waves at the base of these cliffs cause slumping and the cliff sediment collapse on on the beach. Storm can lead to an increase erosion

Once bays are formed they become protected by the headland and so are less eroded

The hard rock is left jutting out into the sea and forms headland

Once formed the headland is then left more vulnerable to erosion and the wave energy is concentrated here

Question 18

Formation of split

Answer 18

Prevailing winds come at an angle

The smash come at an angle and the backwash goes vertically straight out to the sea

This creates a zig zag movement known as longshore drift

The split develops where there is a change in direction of the coastline hook by the wave in the other direction

Question 19

Formation of sand dunes

Answer 19

The sand is blown by the wind

Obstacles/plant causes the wind to slow and deposit sand
—> this increases size of the obstacle I.e the dune grows

Question 20

Beaches

Answer 20

The smash carries the deposit to the collapsed rock of attrition and longshore drift carries further deposit

The coast material is deposited at the upper limit reached by the swath and the back wash leaves the smallest material last

Question 21

Factors for coral reef

Answer 21

Coral reef are found in or near the tropics

1. TEMPERATURE- mean annual temperature has to be over 18 optimum 24
2. DEPTH- can only grown in the water less than 25 metres deep
3. LIGHT- shallow water allows light for tiny photosynthesising algae providing coral food
4. SALINITY- can only live in sea water with not too high salt
5. CLEANLINESS- water needs low pollution as they are sensitive
6. WAVE ACTION- prefer high energy, ensuring freshly oxygenated water
   —> helps clean out trapped sediment brings plankton but maybe destroyed of too exposed
7. EXPOSURE TO AIR- coral die if they are exposed for too long to arise they can only survive and grow at low tide level

Question 22

Explain why many people live on or close to the coast even though it may be hazardous

Answer 22

Employment of tourism

Leisure activities like fishing

Fresh air

Can’t afford to move

Friends and family

Risk perception

Question 23

Explain why living on or close to a coast can be hazardous

Answer 23

Loss of garden

Damages to road

Rising sea level

Tsunami

Coastal erosion

Tropical storms

Properties collapse

Question 24

Slumping

Answer 24

Often occurs in sedimentary rocks trigger by extreme weather

Rocks can fall suddenly to the beach leads to bite shaped chunks are removed from the top of the cliff

There will be a fan shape at the foot of the cliff

Caused by

• winter storm erode the foot of the cliff
• weathering weakens the strength of the cliff
• loosely compacted rocks is permeable, water being absorbed during heavy rain extra weight been given slumping might occur

Question 25

Explain why living on or close to a coast can be hazardous

Answer 25

Coastal erosion
Properties to collapse 
Damage roads
Coastal flooding 
Tsunami
Tropical storms
Rocks fall
Loss of garden