912919
Description
Mind Map by MARINA POLITIS, updated more than 1 year ago
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Created by MARINA POLITIS
over 10 years ago
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Norfolk Coast
- A case study of:
- landform
management
schemes
- landforms
affecting
people's
activities
- landform
management
schemes
- Landforms at Sidestrand / Overstrand Cromer
- cliffs
- the solid geology along this stretch of coast is chalk (at
overstrand chalk lies about 5m below the beach level).
Above the chalk lie superficial deposits of unconsolidated
glacial deposits: sands, gravels and clays. These are
visible in the cliffs.
- 60-70m high
- they have a fine, soft texture
- Thin bands of
harder material
are throughout
- where heavier sands/gravels
were carried further in a time of
greater melting due to higher
temperature
- where heavier sands/gravels
were carried further in a time of
greater melting due to higher
temperature
- the solid geology along this stretch of coast is chalk (at
overstrand chalk lies about 5m below the beach level).
Above the chalk lie superficial deposits of unconsolidated
glacial deposits: sands, gravels and clays. These are
visible in the cliffs.
- beach
- sand, pebbles, cobbles
and flints which have
been washed along the
coast, accumalating to
form a beach
- sand, pebbles, cobbles
and flints which have
been washed along the
coast, accumalating to
form a beach
- cliffs
- How were the cliffs formed?
- formed by materials
transported by ice
sheets over the last
two million years
- the ice sheets
eroded &
transported
deposited rock
materials of
different kinds.
- the main material is glacier till;
tougher, grey, sandy boulder
clays & outwash from Glaciers
in Scotland and Scandinavia
- some tills
have remains
of pebbles of
chalk, flints &
quartz
- some tills
have remains
of pebbles of
chalk, flints &
quartz
- When the glaciers melted
and retreated some left in
sheet form, some in Ridges
e.g. Cromer Ridge
- Active melting gave
floodwater which
could carry materials
further from the snout
of the glacier
- Finer clays and
sediment were carried
away from the snout in
the water
- this is how the cliffs were created
- this is how the cliffs were created
- Finer clays and
sediment were carried
away from the snout in
the water
- Active melting gave
floodwater which
could carry materials
further from the snout
of the glacier
- the main material is glacier till;
tougher, grey, sandy boulder
clays & outwash from Glaciers
in Scotland and Scandinavia
- the ice sheets
eroded &
transported
deposited rock
materials of
different kinds.
- formed by materials
transported by ice
sheets over the last
two million years
- How was the beach formed?
- materials are broken up by the sea eroding cliffs.
- erosion occurs by:
- attrition
- corrasion
- undercutting
- abrasion
- solution
- attrition
- once material erodes it is transported up-coast and deposited
- this is longshore drift
- material is
washed up the
beach at the
angle of waves
but comes back
down the beach
at right-angles
- When wave direction is at
another angle this leads to
movement along the coast,
like a saw tooth motion.
- up the beach this is called
swash and down the beach it is
called backwash
- if swash is stronger than
backwash more material
is deposited than taking
away - creating a beach
- vice-versa it is reduced
- vice-versa it is reduced
- if swash is stronger than
backwash more material
is deposited than taking
away - creating a beach
- up the beach this is called
swash and down the beach it is
called backwash
- When wave direction is at
another angle this leads to
movement along the coast,
like a saw tooth motion.
- material is
washed up the
beach at the
angle of waves
but comes back
down the beach
at right-angles
- this is longshore drift
- erosion occurs by:
- materials are broken up by the sea eroding cliffs.
- Why are the beaches and cliffs in the area vulnerable?
- weak geology -
mainly sands, gravels
(porous and
permeable) and clays
(porous and
impermeable)
- clays intercept
water weakening
the cliff
- the weight
of the clay
can lead to
slumping
- clays intercept
water weakening
the cliff
- common North Sea
storms create
strong winds and
waves
- English
channel and it's
entrance are
narrow meaning
water levels
can be very
high
- Sometimes
defense
strategies in one
area can
undermine
cliffs/beaches in
other areas
- freeze-thaw
action and
chemical
weather due
to slightly
acidic rain
- weak geology -
mainly sands, gravels
(porous and
permeable) and clays
(porous and
impermeable)
- see mind-map on Norfolk coastal
defenses and community views
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