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COASTS
The Coast is.........................
MASS MOVEMENT
• This is where the coastline is altered
because of LAND processes.
1. Mudflow
2. Rockfall
MASS MOVEMENT
• This is where the coastline is altered
because of LAND processes.
3. Landslide
4. Rotation Slip
Types of Weathering
1. Mechanical
Weathering:
Freeze – Thaw
• Rocks are
broken down by
the action of ice
2.Chemical Weathering
• This is called SOLUTION. As sugar
dissolves in tea, some rocks dissolve in
rainwater.
• Some alkaline rocks (chalk and limestone)
are attacked by a process called
CARBONATION which is acidic rainfall
dissolving them.
3. Biological Weathering
• This is where rocks are
broken down by the
action of burrowing
animals and growing
plants
• Roots of trees can create
great pressure and rocks
can be split apart
Coastal Processes:
from the sea
acting on the coast
Erosion
Transportation
Deposition
Types of Wave:
1) Destructive – results in
features/landforms of erosion
Types of Wave:
2) Constructive – result in
features/landforms of deposition
Forms of Coastal Erosion:
1. Corrasion – waves throw sand and
pebbles at a cliff and wear it away.
2. Attrition – stones and pebbles smash into
each other and break into small pieces,
eventually becoming sand.
3. Solution – certain rock types (eg. chalk)
react with sea water and dissolve.
4. Hydraulic Action – force of waves
crashing into cliffs, air gets trapped in cracks
making pressure which cracks the rock.
A process of Transportation –
Traction
Pebbles roll along the bottom of the
sea bed.
A process of Transportation –
Saltation
Pebbles bounce on the bottom of the
sea bed.
A process of Transportation –
Suspension
Smaller pebbles are carried in the
water. Not touching the seabed.
A process of Transportation –
Solution
Particles are dissolved in the water
and transported
Why do we get headlands and bays?
Bays
Headlands
Hard rock
Soft rock
Coastal Processes:
from the sea
acting on the coast
Erosion
Transportation
Deposition
GROYNE
Longshore Drift
Why was geology important in the
formation of Lulworth cove?
Softest
Rock
Hardest
Rock
What coastal landforms can you get and how are they formed?
1
2
6
5
8
3
9
10
4
7
11
Features created by Erosion
Caves, Arches, Stacks and Stumps....
Headland
The
The
sea,
of
continues
the
archto
is
The
Atop
crack
sea,
through
appears
erode
The
eroded
top
the
by
weathering.
the
until
stack
the
is
hydraulic
from
aofcave
weakness
action
and
in
eroded
caves
Both
reaches
from
from
plants
weathering
the other
and
corrasion
the
headland
erodes
the
the
and
side
weather.
the
of the
bottom
from
top
crack
intoheadland
aThe
cave
waves..
fallscausing
inThe
and top
results
an arch
fallsinoff
a
resulting
stack.
in a stump
Stack
Stump
The Sea
What depositional landforms can you get and how are they formed?
Case Studies:
Coasts:
1. Impacts of Rising Sea level = The Maldives
2. Recent Cliff Collapse = Holderness Coastline
3. Coastal Management (Costs/Benefits) =
Holderness Coastline
4. Coastal Habitat with distinct Characteristics
= Keyhaven Salt Marsh, Hampshire
1. The Impacts of Rising Sea Level
THE MALDIVES
The Maldives
• 300 000 people
• 1190 islands, 80%
of the land is 1m
below sea level!
• Sea levels are
rising by 0.9cm a
year.
What is Global Warming?
What are the affects on coastlines?
What are the figures?
What is causing the rise?
Ice cap and Glacier melt
PLUS thermal expansion
Collapse of the West Antarctic ice sheet and Greenland
could cause a 6 metre rise and could happen within a 100
years!!!! This image is a computer generated simulation of
what could happen in the future to the UK…………………..
1. Loss of
Tourism
4. Buying
land in other
countries
2. Loss of
beaches
The IMPACTS of
rising sea level
3. Loss of
Coral Reefs
5. Disrupted
fishing
industry
7. Loss of
Soil
6. Houses
destroyed
Which are:
• Economic
8.Asking for
aid
1. Loss of
Tourism
4. Buying
land in other
countries
2. Loss of
beaches
The IMPACTS of
rising sea level
3. Loss of
Coral Reefs
5. Disrupted
fishing
industry
7. Loss of
Soil
6. Houses
destroyed
Which are:
• Economic
8.Asking for
aid
1. Loss of
Tourism
4. Buying
land in other
countries
2. Loss of
beaches
The IMPACTS of
rising sea level
3. Loss of
Coral Reefs
5. Disrupted
fishing
industry
7. Loss of
Soil
6. Houses
destroyed
Which are:
• Environmental?
8.Asking for
aid
1. Loss of
Tourism
4. Buying
land in other
countries
2. Loss of
beaches
The IMPACTS of
rising sea level
3. Loss of
Coral Reefs
5. Disrupted
fishing
industry
7. Loss of
Soil
6. Houses
destroyed
Which are:
• Environmental?
8.Asking for
aid
1. Loss of
Tourism
4. Buying
land in other
countries
2. Loss of
beaches
The IMPACTS of
rising sea level
3. Loss of
Coral Reefs
5. Disrupted
fishing
industry
7. Loss of
Soil
6. Houses
destroyed
Which are:
• Social?
8.Asking for
aid
1. Loss of
Tourism
4. Buying
land in other
countries
2. Loss of
beaches
The IMPACTS of
rising sea level
3. Loss of
Coral Reefs
5. Disrupted
fishing
industry
7. Loss of
Soil
6. Houses
destroyed
Which are:
• Social?
8.Asking for
aid
Case Studies:
Coasts:
1. Impacts of Rising Sea level = The Maldives
2. Recent Cliff Collapse = Holderness Coastline
3. Coastal Management (Costs/Benefits) =
Holderness Coastline
4. Coastal Habitat with distinct Characteristics
= Keyhaven Salt Marsh, Hampshire
LO1: To know what management strategies there are
Guess The Coastal Management
LO1: To know what management strategies there are
Guess The Coastal Management
LO1: To know what management strategies there are
Hard or Soft?
A
1. Match up the defence with their names
2. Are they are Hard or Soft forms of
engineering
8. Revetment
D
H
C
B
F
E
G
Which form of coastal management is the most sustainable?
Think about Economically (Money), Environmentally (Natural Environment)
and Socially (People)
Sea Wall
Cost: £3,500-5,000 per Metre
Lifespan: 100 years
Gabions
Cost: £1,000 perM3
Lifespan: 10 Years
Wooden Groynes
Cost: £1,000 per M
Lifespan: 30-40 Years
Beach Replenishment
Cost: £5,000-200,000 per 100m
Lifespan: 1-10 years.
2&3. The Holderness Coastline:
Cliff Collapse and Coastal Management
A case study to show an area of cliff collapse- rates of erosion, reasons why
some areas are susceptible, how people may make the situation worse, impacts
on people’s lives and the environment
2m lost a
year!!!
Unstable cliffs can often collapse if they are
undercut by wave action, weathering, or are
susceptible to mass movement
As a result of the landslide the
edge of the cliff recedes.
2&3. The Holderness Coastline:
Cliff Collapse and Coastal Management
The costs and benefits of coastal management
Mappleton:
• 50 Properties
• 2m a year lost
• Access road only 50m from the coast now!
Geology:
• Areas rock is Till (Very soft!)
Management:
• 1991
 £2million on 2 x Rock Groynes and a
rock revetment
 These created a beach, reducing
erosion.
HOWEVER…. Down coast erosion has
INCREASED!! Even on a neap time (30% lower
than a normal tide) the waves reach the cliffs
and erode them!!
What else is causing
the erosion apart
from Geology?
Businesses lost or
under threat.
Farmland Eroded
House Prices
Reduced,
Insurance companies
wont pay out
Homeowners wont get
insurance OR it will be
VERY expensive
Loss of homes at
Withernsea
Use a Case Study to
describe the effects of
coastal flooding (4 Marks)
Explain why areas such as Lyme
Regis use both hard and soft
engineering strategies
(8 Marks)
Case Studies:
Coasts:
1. Impacts of Rising Sea level = The Maldives
2. Recent Cliff Collapse = Holderness Coastline
3. Coastal Management (Costs/Benefits) =
Holderness Coastline
4. Coastal Habitat with distinct Characteristics
= Keyhaven Salt Marsh, Hampshire
4. Keyhaven Salt Marsh, Hampshire
A coastal habitat with distinct characteristics
• How its been formed
• Its features
• What plants and animal species
are there
• Ways to conserve sustainably
whilst still using the area
Hurst Castle Spit
Keyhaven Salt
Marsh
Cordgrass
Wold Spider
Sea Lavender
Ringed Plover
Oyster Catcher
How are these suited to
life on the spit?
Conservation and Sustainable Use
• What pressures does the salt
marsh face?
– Sea Level rise and Climate
change causing severe storms
and flooding. (Loss of 6m a
year)
– Breaching of the spit (1989)
• How will it be conserved?
– 1996 (£5 million) Rip Rap
Installed and Beach
Nourishment
– Protected by SSSI status –
acess and development limited
Use a Case Study to explain
why a coastal habitat has
distinct characteristics
(8 Marks)
Using a case study, discuss the
effects of cliff collapse on peoples
lives and the environment
(8 Marks)