Coast Flashcards
What’s a coastline?
A place where the land meets the sea.
What is weathering?
A breakdown of rock in ‘situ’ (where they are)
3 types of weathering…
Mechanical
Biological
Chemical
What’s mechanical weathering?
Weathering causing physical changes to the rock shape.
What’s biological weathering?
Plants and animals weakening the rocks structure.
What’s chemical weathering?
Weathering that causes a chemical change to the rocks structure.
Mechanical weathering includes..
Freeze thaw
Wetting and drying
Biological weathering includes…
Roots from plants burrowing their way into the rock
Animals
Chemical weathering includes…
Carbonation( acid rain)
Oxidation
What is mass movement ?
Downhill movement of material under the influence of gravity
4 types of mass movement..
Rock fall
Landslide
Mud slide
Slumping
Rock fall is…
Quickest form of mass movement
Rock breaking away from cliff face, usually due to freeze thaw.
Rocks at bottom are called a scree slope
A landslide is…
Rock sliding down cliff
Rocks/ matarial maintain contact with the cliff as they fall
What is a mudslide…
Saturated soil flowing down a slope
Happens rapid, after a period of heavy rain
What is slumping?
Saturated soil slumping down a curved surface
Material rotated backwards towards the cliff face
What is the swash of a wave?
Wave travelling up beadh
What’s the backwash of a wave
Wave travelling down the beach
Is Swash constructive/destructive?
Constructive
Is backwash constructive/destructive
Destructive
Types of erosion at the coastline…
Hydraulic action
Solution
Abrasion
Attrition
( same as in rivers)
Rate of erosion is affected by….
Destructive / constructive waves
Swash/ backwash
Type of rock
Force of waves
3 types of rocks….
Sedimentary
Metamorphic
Igneous
A headland is…
An area of resistant rock that protrudes from the coastline eg. Granite
A bay is…
An area of less resistant rock between two headlands which is quickly eroded
What is a discordant coast?
Alternating bands of hard and soft rock ….
Hard rock
Soft rock
Hard rock
Soft rock
What is a wave cut notch?
Eroded area (indent) at the bottom of the cliff due to destructive waves
Eventually gets deeper and forms an undercut, before it collapses to form a wave cut platform.
What is a wave cut platform?
A wide, gently sloping surface found at the foot of a cliff.
What is CASS in coats
1CAVES
2ARCHES
3STACKS
4STUMPS
Types of transportation in coasts( same as rivers)
Suspension
Solution
Traction
Saltation
What is transportation
The movement of sediment via water
Main direction of wind travel is called..
Prevailing winds
The uks main prevailing winds come from the …
South-west
What is longshore drift?
Transport of sediment along a beach due to waves approaching the beach at an angle
/I/I/I/I/I
How will the swash travek up the beach ?
In the direction of prevailing winds.
How will the backwash travel down the beach?
The back wash will always return at 90 degrees to the beach due to gravity
What is a beach?
A beach is the temporary deposition of sand and shingle along the coastline
The 2 types of beaches…
Sandy beach
Pebbles beach
Sandy beach characteristics
Flat
Constructive waves
Small sediment
Wide
Pebbles beach characteristics
Steep
Destructive waves
Larger sediment
Thinner
What is deposition ?
When a wave looses energy and drops material it’s carrying
Deposition occurs when…
Low winds
Sheltered areas
Shallow water
Low energy
3 landforms of deposition
Beaches
Spits
Bars
What is a spit?
A long part of sand or shingle that extends from the coastline, formed due to deposition
A case study example of a spit?
Dawlish warren spit
What is a bar?
A bar is a barrier of sand stretching across a sheltered bay.
What is a tombolo?
A deposition landform where an island becomes attached to the mainland by a narrow piece such as a spit or a bar
Environment for sand dunes to form( acronym)
Sand
Winds
Objects
Plants
What is an aolian process?
Prevailing winds transporting sediment
The three types of aeolian processes…
Suspension
Saltation
Creep
Structure of a sand dune as you move inland..
More vegetation coverage
More soil nutrients
More established
What is hard engineering?
Using artificial structures to control natural processes
What is soft engineering
Sustainable approach of managing the coast without artificial structures
Three examples of hard engineering at the coast
Sea wall- wall placed against the sea, curved surface reflects waves back out to sea
Gabions-wire cages filled with rocks stabilising the cliff and providing a barrier
Rock armour - rocks placed on the beach to break the energy of the waves
Two examples of soft engineering at the coast..
Dune protection - fences that go around dunes, helps encourage dune formation
Beach replenishment- adds new sediment to beach to make it higher and wider
Advantage and disadvantage of a Sea Wall (Hard engineering)
Advantage- often has a walkway for people to walk along or fish off
Disadvantage - very expensive and High maintenance
Advantage and disadvantage of Gabions (Hard Engineeing)
Advantage - cheaper then other methods
Disadvantage- the wire rusts after 5-10 years
Advantage disadvantage of rock armour ( hard engineering)
Advantage -often fished off
Disadvantage- can look very unattractive
Advantage and disadvantage of dune protection ( soft engineering )
Advantage- minimal impact on ecosystems
Disadvantage- easily destroyed (high maintenance )
Advantage and disadvantage of beach replenishment ( soft engineering)
Advantage - relatively cheap
Disadvantage- constant maintenance
Where is Dorset?
South west of England
What is a concordant coast
Bands of different rock type running parallel to the coastline
What’s a discordant coast ?
Layers of rock running at right angles to the coastline.
THE LANDFORMS OF DORSET COAST.. (acronym)
C hesil beach ( a bar)
O ld harry (cass)
L ulworth cove (bay)
D urdle door (headland reproved to arch)
S wanage bay ( beach)
