1. Welcome to GCSE Geography

2. Name
Mr Rogers Geography
June 2012 Exam
Coasts and Rivers
Hazards
Economic Geography

3. Rivers and Coasts
32% of final Mark
Final exam June 2011 and Controlled
Assessment

4. Economic Geography
16% of final Mark
Final exam June 2011

5. Settlement and Population
25% of final Mark
Sustainable Decision Making Exam
Jan 2012

6. Hazards
16% of final Mark
Final exam June 2011

7. Where are you now?
0 240
C - 144
Your target in to get at least 40 / 60 marks in the Controlled Assessment. 24
available for this project.
CA SDME

8. Help!
drogers@priory.portsmouth.sch.uk
www.facebook.com/classroomgeography
@priorygeography
www.classroomgeography.blogspot.com
Workshop Wednesday

9. Homework Due Wednesday 14th September
Produce a factfile of a place that has been eroded by
the coast
Email to drogers@priory.portsmouth.sch.uk

10. Starter: How did this feature form? (4)

11. Marine Erosion
Processes
VV ‘05

12. The force of waves
hitting a cliff (or sea
wall) compresses
water and air into
cracks and joints. This
can be equivalent to
30,000kg per square
metre.
This increase in
pressure may lead to
cracks widening and
pieces of rock breaking
off.
Hydraulic Action

13. Corrasion (abrasion)
Rock fragments may be picked
up by waves and thrown
against the rock face of cliffs
by subsequent waves.
The effectiveness of the
corrasion depends on the
strength of the wave, the
nature of its ‘load’ and the
resistance of the rock in the
cliff face.
Corrasion is most effective at
the base of cliffs

14. Attrition
Currents and tidal
movements cause the
fragments to be swirled
around and to grind against
each other.
This type of erosion
produces pebble beaches.

15. Corrosion
Salts and acids in sea
water can react with
rocks , slowly
dissolving them away.
.

16. Why does erosion matter?
Video

17. Create four ‘Kung Fu’ actions to represent each
coastal erosion process

18. How have coastal processes shaped this landform? (4
marks)

19. http://www.flickr.com/photos/geographyal
ltheway_photos/sets/72157621775281810
/with/319733211/
• Look at the landforms.
• What factors affect the rate of erosion?

20. http://www.bgs.ac.uk/opengeoscience/go
oglemaps625/default625.htm
• Google mash up

21. Rates of erosion depend on many factors:
• Waves – strength, frequency, height
• Weather – frequency of storm conditions
• Geology of the coastline :
type of rock
degree of resistance
stratification
stability

22. Coastlines of Erosion
1. Headlands and bays
2. Cliffs and wave cut platforms
3. Headland erosion and the formation of caves,
blowholes, arches, stacks and stumps

23. Headlands and bays
• These are most likely to be found in areas where alternating
resistant and less resistant rock meets the coast at right
angles
• Erosion erodes the softer rocks more quickly forming bays
• Headlands are formed of rocks which are more resistant to
erosion

24. Softer rock
Harder rock
Harder rock

25. chalk
clay
limestone
Swanage
Bay
An example of headlands and
bays on the Dorset coastline…

27. The waves attack the base of the cliff through the processes
of abrasion, corrosion, hydraulic action and attrition.
Over time the cliff will be undercut and a wave-cut notch is
formed.
Eventually the cliff becomes unstable and collapses. Further
cliff retreat will form a wave-cut platform.
The formation of
cliffs and wave
cut platforms

29. Wave cut notch - Auchmithie

30. Destructive coastlines

31. Destructive Waves
• BACKwash is stronger than the Swash
• Cause EROSION
• Draw the annotated Destructive wave
diagram on p 89

32. Exam Question:
Name features X
and Y. Explain
how they
formed. Use an
annotated
diagram in your
answer. (5)
X
Y

33. The waves attack the base of the cliff through the processes
of abrasion, corrosion, hydraulic action and attrition.
Over time the cliff will be undercut and a wave-cut notch is
formed.
Eventually the cliff becomes unstable and collapses. Further
cliff retreat will form a wave-cut platform.
The formation of
cliffs and wave
cut platforms

35. 1
High Tide
Low Tide
Corrasion occurs
between high and low
tide- rocks are
hurled at the base of
the cliff.

36. 2
Wave Cut Notch
Eroded
material
available to
take part in
corrasion.
Cliff is undercut,
leaving it
unstable.

37. 3
Cliff retreats
Wave Cut
Platform-
corrasion can
not occur
below low
tide.
Wave Cut Notch
The process of
corrasion will
continue…

38. 4
Cliff retreats
Wave Cut
Platform.

39. Using the terms
below, produce a four
picture storyboard
explaining the
process that produces
a wave cut platform.
High Tide
Low Tide
Wave Cut Notch
Corrasion
Retreat
Wave cut
platform
Cliff

40. Headland erosion

41. Caves, arches, stacks and stumps

42. Caves
Caves usually develop from widening
and deepening of notches where
there are weaknesses in the cliff face
This large cave at Arbroath is fault
guided.
Can you see the fault?

43. Erosive waves may blast their way
vertically through lines of weakness
in the roofs of caves.
This produces a blowhole on the
cliff top.
In stormy conditions sea spray may
spout from blowholes.
Blowholes

44. This huge blowhole is the Gaylet Pot near Auchmithie. The tractor on the
skyline is at the top of the cliffs.

45. Arches
These are formed by the
wearing away of narrow
headlands often by two
back-to-back cave
systems joining.
Durdle Door
The waves continue to erode at the foot of the arch widening it. Eventually the roof
of the arch can no longer be supported and it will collapse.

46. Here a cave and arch are forming on the same headland at
Auchmithie

48. Stacks and stumps
Stacks often represent the seaward remnant
of a collapsed arch. These tall, isolated
pillars of rock such as ‘The Pinnacles’ on the
Dorset coast, are reduced by further wave
action to stumps.

49. The ‘Deil’s Heid’ stack at
Arbroath is interesting
because sea level has
fallen since it was
formed.
There is very little erosion
around its base so it is
unlikely to become a
stump for a very long
time.

50. We can now imagine how
the headland at Durdle Door
might be evolving
Durdle Door in
the past………

51. Durdle Door
As it is at present
………

52. Durdle Door
sometime in
the future?

56. Old Harry Rocks in Dorset which show many of the
features of headland erosion

58. http://www.flickr.com/photos/sacherfire/217113480/

59. 1
You need your
template. This will
represent a chalk
headland.

60. 2

61. 3
Using a green crayon-
shade the middle
horizontal strip- this
represents the top of
the headland- exposed
to weathering.

62. 4

63. 5
Carefully cut out all the
black areas on the
template- with the
exception of the wave-
cut notch.

64. 6
It should look like
this...

65. 7

66. 8

67. 9

68. 10

69. 11

70. 12

71. 13

72. 14

73. 1
2
3
4 5
6

74. About the template...
You could draw your own template or print this slide and use for the model.
The template should be A5 to fit into across a A4 exercise book- of course
you could supersize the model.

75. Write a voice over for the next clip. Your script should
explain how the feature formed

77. Destructive Coastlines
Feature or Land
use
Grid Square
Bay
Headland
Stack
Cave
Ancient use of land
Tourism Car Park 82 80
Camping

79. Why are maps and grid references
vital?

80. Why Grid References?

81. All about Grid References

82. For the exam
• Have to be happy with 4 and 6 figure grid
references

83. Contructive Coastlines
1. Processes of Transportation
2. Features of Coastal Deposition :
Beaches and Sand Dune Systems
Spits
Bars and Tombolos
VV ‘05

84. Constructive waves
• Diagram on page 89

85. BackwashSwash
Transportation of beach material
• Prevailing winds cause
waves to approach the
beach at an oblique angle
• Swash pushes beach
material diagonally up the
beach
• Gravity pulls the backwash
at right angles back to the
sea taking beach material
with it
• Over time this moves
material along the beach in
a zig-zag fashion

86. This movement of sediment
along the coastline is
called..
Direction of movement
swas
h
Backwash is always at
right angles to the
beach
Longshore Drift

88. Groynesare sometimes built (as here on Aberbeen beach)
to counteract the process of longshore drift and encourage the
accumulation of sand.
This can,
however, result
in depletion of
sand and an
increase in
erosion further
along the
coastline……

89. ……such as here at Barton-on-Sea on the south coast of
England where the groynes at Christchurch have
deprived this stretch of coastline of beach material. As a
consequence, the beach at Barton has almost
disappeared and the cliffs are eroding.
To prevent further erosion, rock
armour (rip rap ) has been
placed on what is left of the
beach

90. Beaches develop where the supply of sediment exceeds loss through backwash and
longshore drift. Beaches are usually distinguished as either …
Shingle
or Sand
Shingle beaches are free draining so there is little backwash of
material to sea. As a consequence, they are usually steeper.

91. Some features of
a shingle beach ..
largest material is
furthest from the sea
Successively
lower berms
Berms represent
successive levels of
beach material from
storms and high tides

92. Sand beaches have a
more gentle profile.
This is the result of a
number of factors…
Wet sand compacts so water doesn’t drain
through it. This means that backwash, and the
material it is carrying, is able to return to the sea.
Sand is smoother
than shingle so
there is less
friction to
prevent the
return of beach
materials to the
sea

93. But that’s a story for another
As on-shore winds blow across dry beach sand, it carries material
inland to form sand dune systems

94. Spits and Bars
Where there is a change in the coastline e.g. a
headland or an estuary mouth, longshore drift may
continue to deposit sediments into the sea forming a
spit.

95. Spurn Head at the mouth of the Humber estuary is a
fine example of a spit.

96. Local currents and changes in wind direction may
curve the end of the spit landwards creating a
hooked tip.
The presence of the estuary discharging river water
into the sea prevents the spit from developing into a
bar.
Such a feature is known as a recurved spit
wind

97. If a spit joins one part of the mainland to another it is called a
bar.

98. For example, there is a bar at Slapton Sands in Devon.

99. Tombolo
Where a spit
joins the
mainland to an
island a
tombolo may
be created .
The longest and best known tombolo in Britain is Chesil
Beach.

100. Chesil Beach viewed from the Isle of Portland

101. How people use coastal landforms
Landform How used Constructive or
Destructive?
Beachy Head – Headland Tourism – sight seeing Destructive

102. With thanks to:
Val Vannet,
Dan Raven-Ellison, and
Tony Cassidy