Costal Environments

Question 1

Describe a constructive wave

Answer 1

Strong swash

Weak backwash

Question 2

Describe a destructive wave

Answer 2

Weak swash

Strong backwash

Question 3

Explain the erosional processes.

Answer 3

Hydraulic action - air in a rock crack, sea water crashes against it and forces rock to break apart as air has nowhere else to go
Abrasion - rocks rub together and scour the coast
Corrosion - sea water corrodes the rocks and slowly dissolve
Attrition - rocks bash together

Question 4

Explain longshore drift

Answer 4

Eroded rock is picked up by waves and dragged along the coast.
Moves in direction of wind.
Backwash is at 90 degree angle to swash.
When run out of energy or coastline changes direction, sediment is deposited forming depositional landforms.

Question 5

What are the three land processes?

Answer 5

Weathering - freeze-thaw, salt crystals, acid rain
Erosion - wind and rain
Mass movement - gravity, slumping and landslides

Question 6

What is a concordant and discordant coastline?

Answer 6

Concordant - straighter coastline, outcrops run parallel to the sea, eroded to form wave cut notch, if hard rock is on edge, rock crashes down, if soft, rock slumps down

Discordant - rocks outcrop at right angles, eroded to form headlands (by crack, cave, arch etc) and bays - different strengths of rock on the coastline

Question 7

How are caves, arches, stacks and stumps formed?

Answer 7

Erosion in a headland opens up to a cave
The cave extends back to form an arch
The arch widens and the roof collapses
A stack is left separated for the headland
Further erosion cause a stump

Question 8

How are spits formed?

Answer 8

• long shore drift occurring along coast
• coastline changes direction
• waves have to drop sediment forming a spit

Question 9

How are waves created?

Answer 9

By winds as they blow over the surface of the sea

Strength depends on the wind and fetch

Question 10

What is a tombolo?

Answer 10

Spits that have continued to grow and joined to an island.

Question 11

What is a cuspate foreland?

Answer 11

Triangular shape accumulations of sand and shingle

Longshore drift has occurred from two directions

Question 12

What are sand dunes?

Answer 12

Made up of dry sand blown inland by wind
Forms series of ridges
Vegetation helps stabilise them

Question 13

What factors affect coasts?

Answer 13

Geology
Vegetation
Sea level changes
Human activities

Question 14

Explain what a submergent coastline is

Answer 14

When sea level rises

Downward river valleys and glacial valleys

Question 15

Explain what an emergent coastline is

Answer 15

Falling sea level

Raised beaches

Question 16

What conditions do coral reefs need to grow?

Answer 16

Temperature - 23-25 degrees C
Shallow water for more warmth and light - less than 25 metres deep
Wave action - oxygenated salt water 
Exposure to air - too long they die 
Sediment - clean water
No alge - alge can suffocate
Fish to inhabit

Question 17

Where are coral reefs distributed?

Answer 17

Between the Tropic of Cancer and Capricorn

Question 18

Where are mangroves found?

Answer 18

Within 30 degrees latitude of the equator

Question 19

Describe what a mangrove is and what it does?

Answer 19

One foot on land one in the sea 
Live in a changing environment 
Range in size from shrub to 60m
Filtration System keep salt out 
Make new land

Question 20

What are the main reasons for coastal conflict?

Answer 20

• all competing for same site
• reclaiming land
• no special protection or conservation areas
• over developed
• no protection plan

Question 21

What are the threats to coral reefs?

Answer 21

Humans taking bits of coral
Pollution
Overfishing
Coral for building stones
Farm run off
Sea level change
Sea temperature rising

Question 22

What are the threats to mangroves?

Answer 22

deforestation
land reclamation
herbicides
aquaculture

Question 23

Give an example of hard and soft engineering?

Answer 23

hard - sea wall, rip rap, rock islands, gabion, break water

soft - beach replenishment, managed retreat, fencing

Question 24

What are the advantages or disadvantages of engineering?

Answer 24

Hard
adv - quick, effective
dis - can be expensive, unattractive

Soft
adv - cheaper generally
dis - doesn’t last as long, not effective

Question 25

Why are coasts constantly changing?

Answer 25

Used by humans Weathered Eroded Transported

Question 26

Explain how headlands retreat to produce new coastal landforms.

Answer 26

Front on: Cliffs & Wave Cut Platforms: - waves form wave cut notch via abrasion - overhang becomes too heavy - collapses (either crashes or slumps) and headland retreats - draw diagram Side on: Crack, Cave, Arch, Stack, Stumps: - sea erodes areas of weaknesses i.e. cracks - further erosion leads to larger cracks developing into small caves - further erosion widen caves until two caves erode into back of each other forming an arch - wave attack at base of arch weakens structure until roof of arch collapses leaving stack - continued erosion in stack causes collapsing to a stump - stump then covered by water at high tide.

Question 27

What is a bar?

Answer 27

Long shore drift has occurred on the outsides of two headlands making its way to the bar inbetween Waves drop sediment on corners of headlands Over time so much sediment has dropped just inside the bay region of each headland that two piles of sediment join up to form a bar of sediment across a bay

Question 28

What is a beach?

Answer 28

- depositional landform - made up of an accumulation of sand and sediment between high and low tide - created by constructive waves - includes berms and storm beaches

Question 29

How do coasts change with sea level rises?

Answer 29

- rias formed (drowned river valleys) | - fjords formed (drowned glacial valleys)

Question 30

How do coasts change with sea level drops?

Answer 30

- raised beaches formed (wave cut platform emerges) | - relict cliffs formed (caves, arches, stacks emerge)

Question 31

What conditions do mangroves need to grow?

Answer 31

- intertidal zones - tropics - a mix of salt and fresh water

Question 32

What conditions do sand dunes need to grow?

Answer 32

- wind - lots of sand - vegetation

Question 33

What conditions do salt marshes need to grow?

Answer 33

- a mix of salt and fresh water - form behind a spit - calm water

Question 34

What is the importance of, threats to and management of sand dunes and salt marshes?

Answer 34

Importance: - habitat - recreation - protection Threats: - recreation - development Management: - zone off - prohibit development - educate

Question 35

Why is casual conflict caused by different users of the coast?

Answer 35

- conservationists don't want any coastal activities - fishermen want no tourism so they can fish for a living - tourists want water sports and touristic activities

Question 36

Give examples of hard and soft engineering.

Answer 36

Hard: - sea wall - groynes - gabion cages - rip rap - revetments Soft: - cliff stabilisation - beach replenishment - zoning - managed retreat

Question 37

Why are coasts retreating in one named area and how is it being managed?

Answer 37

Barcelona, Spain - long shore drift - increased storms - human activity - huge fetch from South East - beach reolenishment - groynes - breakwaters - rock islands - rip rap

Question 38

For an ecosystem you have studied, discuss the threats to the ecosystem and how successfully they are managed.

Answer 38

Sand dunes - roads / housing / general development - walking (footpath erosion) - litter / pollution - planning laws to restrict development - rope barriers - educational signs - boardwalks, playgrounds - bins, sign posts

Question 39

What is deposition?

Answer 39

When accumulated material / sand / shingle / sediment is deposited all at once.

Question 40

How do headlands and bays form?

Answer 40

- form only on discordant coastlines - (where soft and hard types of rock all meet the sea) - soft erodes more easily forming a bay further back - leaving hard rock in either sides of it as two headlands

Question 41

What factors affect the distribution of coastal ecosystems?

Answer 41

Coral reefs: - temperature - light - water depth - salinity - wave action Mangroves: - warm temps (30degrees latitude of equator) - intertidal zones

Question 42

What are the threats to sand dunes?

Answer 42

Human activities Development Pollution

Question 43

What are the threats to salt marshes?

Answer 43

Development Human activities Reclaimed land