Coasts

Question 1

What are the size and energy of a wave influenced by?

Answer 1

• How long the wind has been blowing.
• The strength of the wind.
• How far the wave travelled (Fetch).

How the waves affect the coastline

Question 2

What is a swash?

Answer 2

Forward movement of a wave up a beach.

How the waves affect the coastline

Question 3

What is a backwash?

Answer 3

Is the movements of waves back into the ocean.

How the waves affect the coastline

Question 4

What is a Constructive wave & Destructive wave?

Answer 4

Constructive Wave: Swash bigger than backwash. (Long wavelength)

Destructive Wave: Backwash bigger than swash. (Short wavelength)

How the waves affect the coastline

Question 5

Erosion, Transportation and deposition.

Define what is Erosion & Transportation & Deposition.

Answer 5

Erosion: Breaking up of land
Transportation: Movement of materials
Deposition: Dropping off of material

More Energy = erosion, Less energy = deposition

Question 6

Erosion, Transportation and deposition.

What is the process of erosion?

Answer 6

1. Hydraulic action - Waves that ‘smash’ into the base of the cliff
2. Atrition - Pieces of rock hit eachother and break off.
3. Abrasion - Rocks that rub against eachother and smooth out.
4. Corrosion - Acids in water dissolve rock

Question 7

Erosion, Transportation and deposition.

What is the process of transportation?

Answer 7

1. Traction - Larger rocks roll along the sea bed.
2. saltation - smaller stones ‘bounce’ along seabed.
3. Suspension - Lighter, finer material carried by the water.
4. Solution - The transport of dissolved chemical rocks.

Question 8

Define Longshore drift.

Answer 8

The zigzag movement of sediment along the beach, strong swash takes particles up onto the beach at an angle (Due to wind direction), backwash when stronger takes them back out at 90 Degrees.

Question 9

What is the deposition on coasts?

Answer 9

• The dropping off of materials, when the wave have no energy.
• Largest/heaviest bits deposited first because too much energy is required to carry them.

Question 10

Mass Movement

Define Mass Movement.

Answer 10

Is the downhill movement of sediment that moves under the influence of gravity and weather

Question 11

Mass Movement

State what they are.

(Rockfall, mudflow, landslide, rotational slip)

Answer 11

1. Rockfall - Bits of rock fall off the cliff face.
2. mudflow - soil flows down a slope.
3. Landslide - Large blocks of rock slide downfall.
4. Rotational slip - Saturated soil slumps down a curved surface.

Question 12

Mass movement.

what is saturated soil?

Answer 12

Soil that has reached the maximum capacity to hold water

Question 13

Physical weathering

What is freeze thaw weathering?

Answer 13

When water gets into a gap and freezes, water expands. Ice melts, larger gap fits with water, repeat until rock breaks

Question 14

Physical wethearing

What is onion skin?

Answer 14

Hot during days, cold at night, surface expands and contact

Question 15

Physical Wethearing

What is Acid rain?

Answer 15

Rainwater is acidic, ‘acidic rain’ weathers rock

Question 16

Physical wethearing

What is biological weathering?

Answer 16

Plants grow in rock, animals walking on the rock

Question 17

Coastal Landform.

How is a headland formed?

Answer 17

On a headland, erosion exploits any source of weakness creating a cave at first. Once the cave reaches both sides of the headland, it forms an arch. A collapse at the top of the arch forms a stack. Once the stack is eroded it forms a stump.

Question 18

Coastal Landform.

What are characteristics of wave-cut notch platform?

Answer 18

1. Found infront of retreating cliffs, extended out to sea.
2. A flat, often smooth surface. exposed at low tide

Question 19

Coastal Landform.

What is a spit?

Answer 19

A depositional land form formed when LSD continues to occur over a coast.

Question 20

Coastal ecosystem

What is a sand dune?

Answer 20

build up of sand complimenting the direction of wind. usually formed in beaches, deserts.
Features:
- vegatation : Plants like marram grass help stabalize the dunes by holding the sand together with their roots.

Question 21

Influences on coastal ecosystem

what is it ment by Geology?

Answer 21

Types of rock:
1. Hard rock.
2. Soft rock.

Remeber Hard rock erodes slower where as Soft rock erodes faster.

Question 22

Coastal ecosystem

What are salt-marshes?

Answer 22

shelterd area of land behind the hook were the tides have very low energy.
Features:
Tidal flooding: The area is regularly coverd by sea water during high tides and exposed during low tides.

They also have high oxygen content.

Question 23

Coastal ecosystem

features of salt marsheses?

Answer 23

• Thye are communities of non-woody, salty-tolerant plants.
• they begin as tidal mudflat gaining height as more sediment is deposited.
• tides very low energy

Question 24

threats to the coastal ecosystem.

What are 4 main threats to the coastal ecosystem?

Answer 24

Industrilistation, Argiculture, tourism, and deforistation.

Question 25

# Threats to the coastal ecosystem. What are the threats to coral reef?

Answer 25

Coral reef can suffer physical damage including: Quarrying, dredging, amd destructive fishing particles. Other threats may include Pollution, Sewage, overfishing, global climate change.

Question 26

# Threats to the coastal ecosystem. What are the threats to mangroves?

Answer 26

They face various threats, including deforestation **from** wood and **charcoal** Clearance for coastal development, pollution, temperature increase from near by power plants.

Question 27

# Causes of coastal flooding. Coastal floods are caused by many factors. what are they?

Answer 27

1. Storm surges 2. tsunami 3. increasingly global climate change.

Question 28

# Causes of coastal flooding. What are storm surges?

Answer 28

A storm surge is caused by a rapid rise in sea level caused by high wind pressure.

Question 29

# Causes of coastal flooding. What is **prediction**?

Answer 29

Most storms are tracked by satelliets, especially though (HIC's) countries. It is difficult to give much notice on tsunamis given their wind speed. Although there is a particular Tsunami warning system.

Question 30

# Causes of coastal flooding? What is building design?

Answer 30

The primary objective of coastal flood engineering is to prevent coastal erosion and coastal flooding. 1. You can raise the height of the buildings, this allows the water to pass beneath the building. 2. Flood proof buildings through raised foundations, reinforced barriers.

Question 31

# Coastal Managment strategies. What is **hard engineering?**

Answer 31

Hard engineerings attempts to manage coastal areas by alternating natrual processes through the use of man-made structures. | They include: sea walls, rock armour, revetments, groynes, cliff drains.

Question 32

# Coastal managment strategies. what is **soft engineering?**

Answer 32

Attempts to manage the coastal erosion/flooding by working with nature. | e.g. Beach nourishment

Question 33

# Coastl managment strategies. Evalute **hard engineering** structures.

Answer 33

what is a sea wall and **advantage & disadvantage**: A sea wall is a solid barrier constructed perpendicular to the shoreline. They are designed to absorb energy and prevent erosion. **advantage:** -provide strong protection against storm - Good in high density areas. -**disadvantage:** - expensive to build & maintain. **Revetments:** A slopping structure made from concrete, rocks or other materials, placed on banks or cliffs. They absorb and deflect wave energy. **advantage:** -reduce wave energy/prevent erosion. -cheaper than seawall. **disadvantage:** - can be expensive to build out and maintain. **Gabions:** rock held in wire cages to absorb wave energy. **advantage:** - relatively cheap to construct. - **disadvantage:** - small scale - **Gryones:** barriers or a wall built perpendicular to the shoreline, extended from the beach to the water. they trap sediment from longshore drift. **advantage:** -reduce coastal erosion locally -easily repaired **disadvantage:** -interupts sediment flow. **Rock armour:** large rock at the base of the cliff to absorb wave energy. **advantage:** durable and requores little maintanence. **disadvantage:** can be costly to transport the necessary material.

Question 34

# Coastal managment strategies evaluate **soft engineering** structures.

Answer 34

**beach replenishment:** samd pumped from seabed to replace eroded sand **advantage:** -looks natrual **disadvantage:** -expensive -short term-solution **cliff regrading:** lowering of slope angle to make cliff safer. **advantage:** -reduces the risk of landslides and erosion **disadvantage:** - can be expensive. - may lead to loss of habitat. **ecosystem rehabitation and revegatation:** restoring coastal ecosystem. **advantage:** -looks natrual. **disadvantage:** - can take long time to achieve. **managed retreat:** allows shoreline to move natrually, coastline allowed to retreat in certain places. **advantage:** -cost effective. **disadvantage:** -unpopular

Question 35

What are Abiotic and Biotic characteristics?

Answer 35

**Abiotic:** 1. water 2. humidity 3. light **biotic:** 1. Animals 2. plant 3. fungi | Remember Abiotic as 'are not living' and Biotic as 'living'.

Question 36

What are requirments of **coral reef**?

Answer 36

-warm water at a minimum temperature of 18. -formed at depth exceeding 25 meters. -grows faster in clear water which allows the sunlight to penetrate -grows in saltwater.

Question 37

what are **disturbution of coral reefs?**

Answer 37

-between 30 north and 30 south of the equator. -between the tropics of cancer and capricorn.

Question 38

What are Mangrove requirnment and distrubution?

Answer 38

**requirment:** - lives in salt water - intertidal zone **disturbution:** -in the tropics

Question 39

Give 3 examples of **erosional** landforms.

Answer 39

- Caves - Arch - Stack - Stump - wave-cut notch - headlands - bays

Question 40

Give 3 examples of **depositational** landforms

Answer 40

- Beaches - Spit - Sand dunes - bars

Question 41

# Sand bar What is a **sand bar.**

Answer 41

Sand Bar is when longshore drift contineous to occur over a bay.