What processes cause beaches
and spits to form in bays?
Homework: due next lesson.
Explain the process of longshore
drift. You may use a diagram to help
with your answer (4)
Homework: from last lesson.
What happened at Holbeck Hall?
Why?
Peer assess another person’s work. Underline
geographically specific vocabulary. How many
words did they use?
Sizeable portrait
Coasts are a dynamic environment subject to
constant shaping and reshaping by the actions of
the waves.
In this lesson you will study the features created
from material eroded by waves and consider their
importance.
The lesson will continue preparation for the
Swanage field visit.
Coming up
• All pupils can explain the process of longshore
drift
• All pupils can identify the features created by
longshore drift.
• All pupils can explain the features created by
longshore drift.
Vocabulary
•
•
•
•
Longshore drift
Bays
Shingle
sediment
What happens to the eroded material
from the cliffs?
What type of wave deposits sediment?
Why are beaches important?
Extra: can you classify the reasons as social, environmental
or economic?
Swanage Beach
How are these two pictures linked?
What will happen to any buildings at the
top of the cliff?
Is there anything to stop the
sea from eroding the cliff?
How are beaches formed?
Beaches form in sheltered environments, such as bays.
When the swash is stronger than the backwash,
deposition occurs.
Sometimes sand from offshore bars can be blown onto
the shore by strong winds.
In such cases dunes may form – such as at Studland on
the Dorset Coast.
Task
Explain why beaches are important.
• Beaches are important because………
How are pebbles and sand
moved by the sea?
In lesson 2 you learnt about Swash and
Backwash
Backwash
Swash
If you tracked a pebble’s progress through swash and backwash where
would it end up? Why?
How is sediment transported along the coast?
Can you predict what will happen when the
animation is started?
Longshore drift
http://www.bbc.co.uk/learningzone/clips/3086.bb.wmv
Direction of movement
Backwash is always at
right angles to the beach
swash
Backwash
This movement of sediment along the
coastline is called longshore drift.
Task
Make an annotated copy of the diagram showing
longshore drift. The annotations should explain
longshore drift.
Your annotations must include the following words:
• Wave
• Swash
• Backwash
• Constructive
Backwash
• Material
Use the labels below to annotate a diagram
showing how longshore drift occurs
A constructive wave
brings material to the
beach
The swash moves the
material diagonally up
the beach
The process is
continued meaning
that the material “zig
zags” along the beach
Backwash moves the
material back down
the beach. Gravity
means it is at right
angles to the beach.
Another constructive
wave pushes material
back up the beach
Backwash
What other landforms does longshore drift
create?
A bar e.g. Chesil Beach
A bar e.g. Chesil Beach
A spit
How are spits formed?
Can you predict what will happen?
Task
Produce a sequenced piece of writing to demonstrate
how a spit is formed. Pages 78-79 may help.
How are spits formed?
What is a tombolo?
If a spit joins the mainland to an island it is called a
tombolo.
At Chesil Beach in Dorset,
the mainland is joined to
the Isle of Portland.
Chesil Beach
Study the photograph.
Y
X
Portland
From what direction was the photograph taken?
Name features X and Y.
What is a bar?
If a spit joins one part of the mainland to another it is
called a bar.
For example, there is a bar at Orford Ness in Devon.
Task
Explain what a spit and tombola is.
Homework: due next lesson.
Explain the process of longshore
drift. You may use a diagram to help
with your answer (4)
Finally: Coastal landforms in Studland