Coasts

Question 1

Define weathering

Answer 1

The process of rocks and artificial structures getting worn away into smaller pieces

Question 2

What are the 3 types of weathering

Answer 2

Physical/mechanical
Biological
Chemical

Question 3

Describe physical weathering

Answer 3

Rain water gets into cracks, freezes into ice and expands causing the rock to crack - freeze thaw

Sun heats rocks which expand in the heat, at night they contract - causing stress -Onion Skin weathering

Question 4

What is biological weathering

Answer 4

Rocks are broken apart by growing tree roots and plants getting into cracks

Question 5

What is chemical weathering

Answer 5

Not a mechanical process

All rain is slightly acidic and the acid reacts with the stone wearing it away/

Sulphur dioxide can make rain more acidic

Question 6

How are waves formed

Answer 6

Waves are caused by wind dragging on the surface of the water.
The length of water the wind blows on is called the fetch.
The stronger the wind, longer it blows for and longer the fetch - the larger the waves will be and more energy they will have.

Question 7

Describe constructive waves

Answer 7

Long + low
Less powerful
Deposit material - build beaches
6-8 per minuet

WHEN SWASH IS STRONGER THAN BACKWASH

Question 8

Describe destructive waves

Answer 8

Strong winds
Short and steep 
Remove material from beach 
15 per minuet 
BACKWASH IS STRONGER THAN SWASH

Question 9

Define erosion

Answer 9

The geological process in which materials are worn away and transported by natural forces such as wind or water. The opposite to deposition

Question 10

What is the difference between weathering and erosion

Answer 10

Erosion involves movement and weathering is static

Question 11

What is Hydraulic action

Answer 11

The power of the waves that smash against the rocks. Water enters cracks which then forces them to break apart

Question 12

What is Abrasion

Answer 12

The process of wearing something away, the rocks grind away at the sea bed or beach

Question 13

What is Attrition

Answer 13

Rocks in the backwash smash against each other. They break apart becoming smaller and more rounded

Question 14

What is corrosion

Answer 14

Where the sea water dissolves certain types of rock

Question 15

Define transportation

Answer 15

The movement of sediment within the sea by waves

Question 16

Give the 4 types of transportation

Answer 16

Solution
Saltation
Suspension
Traction

Question 17

Describe Traction

Answer 17

Pebbles and large sediment are rolled along the seabed

Question 18

Describe Suspension

Answer 18

Small particles are carried in the water e.g sand and clays, which can make the water look cloudy. Currents pick up large amounts of sediment in suspension during a storm, when strong winds generate high energy waves

Question 19

What is solution

Answer 19

Minerals are dissolved in the sea water and are carried in solution. The load is therefore not visible. Load can come from cliffs made of chalk or limestone and calcium carbonate is carried along in solution

Question 20

What is saltation

Answer 20

Load is bounced along the sea bed (small pieces of shingle or large sand grains). Currents cannot keep the larger and heavier sediment afloat fro long periods of time.

Question 21

Describe longshore drift

Answer 21

Is the movement of water in the sea

The prevailing wind blows waves onto the costa at an angle, were they erode.

Tides than take the water and the eroded material back out to sea at right angles to the coast direction.

This means that the water and the material have moved along the coast.

The wind the blows them in again and tides out etc. and continues redoing until the LSD comes up against a natural or human structure that forces it to deposit

Question 22

Define deposition

Answer 22

When the sea looses energy, it drops the sand, rock particles and pebbles it’s carrying. This is called deposition

Question 23

Give some conditions needed for deposition to occur

Answer 23

Constructive waves
Shallow water
Little wind
Sheltered areas (bays)

Question 24

What are concordat coastlines

Answer 24

Occur when the layers of different rock the lie parallel to the sea. As a result they are much straighter and have fewer landforms

Question 25

What are Discordant coastlines

Answer 25

Occur when the layers of different rock types lie perpendicular to the sea. As a result thy create headlands and bays

Question 26

How do Headlands and bays form

Answer 26

They form on discordant coastlines where the rock is perpendicular to the wave direction. The roc is made up of alternating bands of soft and hard rock (clay and chalk). The waves erode the soft rock made by hydraulic action causing the hard rock to jut out into the sea, making soft rock/bays more sheltered.

Question 27

Give the 6 stages and description of the formation of a stump

Answer 27

CRACK -Headlands attacked by hydraulic action, corrosion and attrition. Cracks begin to appear. CAVE -Cracks are widened to creates sea caves on either side of the headland ARCH -Two caves may join together to create an arch. Eventually the ref of the arch will collapse... STACK -Leaving a stack... STUMP -The stack continues to be eroded especially at the base. Eventually the stack collapses to leave a stump or a wave cut platform CLIFF RETREATS -The cliff goes through this process repeatedly causing it to retreat over many years.

Question 28

Explain why deposition occurs at certain places along the coast

Answer 28

Because along the coast there is a variation of sheltered areas and constructive waves. When these occur and there is shallow water, the wave will loose energy and drop the material it's carrying causing deposition

Question 29

Beaches are one of the most common features of a coastline. They are made up of.................material that has been.................. from elsewhere and later.....................by the sea. They can be made up of either............or...............

Answer 29

``` Eroded Transported Deposited Sand Shingle ```

Question 30

What is a spit

Answer 30

An accumulation of sediment with one end attached to the land and the other eating out across an estuary str into the sea.

Question 31

Give 4 conditions needed for a spit to form

Answer 31

LSD Strong prevailing wind Line of coast changes Sediment

Question 32

Describe the life of a spit

Answer 32

The sit forms form an accumulation of sediment with one end attached to the land and the other eating out across an estuary str into the sea. Eventually over time from LSD, this deposition will build up causing it to continually grow across. The hooked end is caused when the prevailing wind changes, pushing the sediment into a lightly different direction

Question 33

What are sand dunes and how do they form

Answer 33

Sand dunes are small ridges or hill of sand found at the top of a beach, above the usual maximum reach of waves. They form from wind blown sand that is initially deposited against an obstruction such as a bush, driftwood or a rock. As more sand parcels are deposited, the dune grows in size.

Question 34

What are coral reefs made from

Answer 34

Hundreds of polyps

Question 35

What are polyps

Answer 35

Mouth with tentacles

Question 36

Give the 4 key conditions needed for cora reef to grow

Answer 36

Shallow water - Sunlight can reach them - Breaking waves give food and oxygen Clean/clear water - Sunlight can pass through - Clean water don't have as many nutrients, so nit much seaweed grows Sunlight - Algae gets energy from sun - over 20˚C Salinity - Optimum levels of salt in water - Freshwater kils coral

Question 37

Give 3 types of coral reefs

Answer 37

Fringing reef - Lies close to shore Barrier Reef - Borders shorelines but located further away Atoll - Ring shaped coral reef, around an island

Question 38

What are mangroves

Answer 38

Shrubs or small trees that grow in costal environments They are tropical costal vegetation, commonly found in the inter tidal zone - the area that is above water at low tide and below it at hight tide They are the only trees that are capable of thriving in salt water and have adapted to living in these conditions in a number of ways

Question 39

Give 3 ways in which mangroves have adapted to their harsh conditions

Answer 39

Filtration system - 90% salt altered out - Excreted from old bark and leaves which drop off. Strong roots - Arial or butters roots - Act as snorkels - String and stable in silty and sandy soil Oxygen -Breathing tubes called pneumatophores -

Question 40

How do mangroves protect the coast against storm surges

Answer 40

The dense roots of the mangroves trap sediment flowing down the river. Tis helps stabilise the land and prevent erosion from waves and storms

Question 41

Why are mangrove swamps a valuable ecosystem for the coastline

Answer 41

Because, not only do they help with costal protection, but also create their own environment supporting biodiversity for the local area

Question 42

What is a hazard

Answer 42

Something that can cause harm to a person, object or the environment

Question 43

What is a risk

Answer 43

The chance, high or low, that any hazard will actually cause harm

Question 44

How do tropical storms form

Answer 44

The sun is directly over the equator, providing energy to the ocean The warm ocean heats the air above it, causing it to rise rapidly Water evaporates quickly from the hot surface of the ocean so the rising air contains great amounts of water vapour The rising air starts to spin As the air rises, it cools and condenses to form cumulonimbus clouds The rapidly rising air creates an area of low pressure. The low pressure sucks air in causing very strong winds Once the storm moves over the land, it looses energy and fades

Question 45

What is soft engineering

Answer 45

Where the natural environment is used to help reduce costal erosion and river flooding

Question 46

Give 3 soft engineering strategies

Answer 46

Beach nourishment Dune regeneration Marsh creation

Question 47

What is beach nourishment and what are the pros and cons

Answer 47

Supplies sand to the shore to secure the beach from shore erosion (£3000 per km) Pros: - Blends in with existing beach - Larger beaches appeal to tourists Cons: - Sand needs to be constantly replaced - Sand has to be brought in from elsewhere

Question 48

What is Dune regeneration and what are the pros and cons

Answer 48

Involves creating or restoring sand dunes The vegetation on the dunes help make it stabilised and provide a barrier to absorb wave energy (£2000 per 100m Pros: - Helps maintain the ecosystem Cons: - Time consuming planting vegetation - Less effective than hard engineering solutions

Question 49

What is marsh creation and what are the pros and cons

Answer 49

Plant vegetation along beaches to stabilise the land Pros: - Stabilises mud flats - Reduces the speed of waves - Creates ne habitats for organisms Cons: - Fairly expensive - Not useful when erosion rates are high because the marsh can't then establish itself