1
Q
Name a human influence that can increase the impit into a beach stor
A
- Beach nourishment
2
Q
Name 4 ways that sed=iment can be transported to the beach
A
- Rivers
- Breakdown of arger particles from beaches elsewhere moved updrift by Longshore drift from updrift
- Breakdown of rock faces from headlands and cliffs
- From deepwater ofshore s3ediments carried and deposited onshore as sea levels rose after the iceage ended
3
Q
name the 4 methords of transportation coastal
A
Solution, suspension, saltation, traction.
4
Q
What is the mode of transportation depend upon incoastal transportation
A
- The size and mass of the particle and the speed of the current
5
Q
What is bedload
A
- When grains are constantly supported by either continuous traction or intermittent saltation with the sea floor
6
Q
what is solution
A
- Minerals in tocks are disolved and carried by the water
7
Q
What is suspention
A
- Small particles are light enough to be suspended in the water
8
Q
What is saltation
A
- Sediment is too large to be transported by suspension so it bounces along the sea bed. sediment are transported in areas of low energy.
9
Q
What is traction
A
- large particles are rolled along the sea bed when currents have lots of energy and they are the first to be deposited when there is an area of low energy
10
Q
what is the hjulstrom curve
A
The Hjulström Curve is a graph used in geography to show how water velocity affects the erosion, transportation, and deposition of sediment in a river.
11
Q
When does longshore drift most commonly take place when the prevaling wind is at what angle
A
- Oblique angle to the shoreline so the swash pushes the material up the beach at a diagonla angle
12
Q
What ahppeneds to the rate of erosion up drift when LSD has moved the material downdrift
A
- increase in the rates of erosion
as the beaches ability to absorb the energy of destructive waves is lower. The same is said if humans influence the rate of erosion due to groynes; he down drift suffers.
13
Q
What is stokes law
A
Stokes’ Law explains that smaller and lighter sediment particles settle more slowly in water than larger and denser particles.
14
Q
What is flocculation
A
- The grouping together of like particles like clay
15
Q
What impact does floculation have on the rate of deposition
A
-Increases the fall velocity and therefore the speed of deposition as the particles that have flocculated together increase their mass therefore are deposited easier
16
Q
What is fall velocity
A
- Fall velocity is the speed at which sediment falls through still water.
17
Q
what can storms do to the bigger rocks
A
- Throw them up the beach above the high watermark to form a storm beach
18
Q
What is sediment sorting
A
- Sediment sorting is the separation of sediment by size.
19
Q
On a noraml beach how is the sediment sorted and why
A
- Largest particles at the top of the beach - strong swash carries them up the beach and weak swash can’t bring them back down the beach - the little particles require less energy to move so they are transported so are lower down the beach.
20
Q
On a storm beach how is the sediment sorted
A
- Large boulders and rocks thrown up the beach due to the extra energy that the have.
- Smaller finer particles are removed from the beach due to offshore due to the increased strength of the backwash wash
21
Q
What type of land form is a beach
A
- Depositional
22
Q
What is the main influence of a beach plan
A
- Wave energy, inparticular the relationship between the waves and the prevailing wind
23
Q
What are the 3 diffrent types of beaches
A
-Swash allined beaches
- Drift allined beaches
- Zeta formed beaches
24
Q
what is a swash allied beach
A
- waves break parallel to the shore
- no longshore movement after equilibrium is established
- sediment transport is onhore and offshore
25
Example of a shwash allined beach
- Lulworth cove
26
what is a drift allined beach
- The waves approach at an angle, the swash moves material up the beach in that direction.
- The backwash returns at right angles straight down the beach, this cause the sediment to drift along the beach.
27
example of a drift allined beach
- Western point bay, Victoria, Australia
28
What is a zeta formed beach
- A combination of both swash and drift allined beaches curved beaches with 2 headlands
- On the near end the beach swash is aligned and the beach profile is dissipative type.
- On the far side the beach is drift aligned as the sediment builds up the beach profile becomes the reflective type.
- Sediment moves along the shore but the movement is trapped between the 2 headlands.
- Sediment is then redistributed along the beach due to varying wave angles.
29
example of a zeta formed beach
- New south wales, austrailia
30
What is a bay head beach
A bay-head beach is a beach located at the back of a bay where wave refraction concentrates sediment, creating a stable, well-sorted beach.
- Swash allined beach, wave refraction focusues the erosion on the surrounding headlands encouraging beach deposition these beaches can be larger is they face the prevaliling wind
31
Where do beaches form
- Intertidal zone between lowest spring tide and highest level reached by the waves, usually a storm beach.
32
What are the 3 factors that influence beach profiles
- Waves and wave energy
- tidal range ( where the waves break on the shore and the amout of beach they break over)
- The type of beach materil ( shape, size, and composition, which effects the beach gradient. )
33
How do beahces change with the seasons
- in the summer the beach profile steepens as calm conditions push material up the beach creating a berm
- In winter the beach profile flattens in stormy conditions material is combed seawards, creating an offshore bar.
34
What does perlocate mean
To pass slowly through a porous material or soil.
35
How is the backwash effected by traveling over rocks
-The rocks will disapate the backwashes energy as the water will perlocate down through rocks therfore reducing the backwashes strength
36
How does longshore drift sediment sort
- Further down the beach or down drift the particles will reduce in size and become smoother and more rounded along the length of the beach.
37
What are spita and where are they found
- Spits are linear deposits of sand and shingle attached to the land at the proximal end but free at the distil end.
- Found where the coast has an abrupt change of direction, such as an estuary or a bay, both of which are low-energy environments
- Needs a ready supply of sediment, particularly sand or shingle
- Longshore drift is active
38
How are spits formed
- LSD - transprts
- major change in coastline eg river may deposit sediment due to the area of low energy gradually building up into a spit.
-Spits can develope to form a bar cutting of large areas of sea and creating coastal lagoons.
39
What is a Cuspate forland
triangular-shaped projections with an apex pointing out to sea.
- present when sediment is moved via longshore drift, when an equilibrium is reached between sediment inputs and energy available to move it.
40
How are cuspate forelands formed
- LSD
- Result from a change in spit growth
- When sand or shingle accumulates in shelter or shoals under the sea.
41
Example of a cuspate Forland
- The Dungeness cuspate Forland
42
What are Tombolos
A narrow strip of sand or shingle connects an island to the mainland or another island.
43
How are tombolos formed
- Longshore drift moves sediment eastwards
- Wave refraction creates an island shadow which is an area of low energy behind the island where sediment builds up.
- This sediment forms a spit and eventually will join to the mainland
44
Example of a tombolo
- Chesil beach Dorset
45
What are bars
- Elongated deposits of sand and shingle ususaly parrellel to the coastline
46
How are bars formed
- LSD
- Prevailing wind creates a drift aligned beach sediment travels down the beach and will be deposited due to low energy environments this can also create a bay bar.
47
Example of a bar
- Slapton ley barrier beach
Issy As-Level geography
flashcards
Decks in class (13)
# Cards
-
Topic 1.1.1 operation of the coast system17
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Topic 1.1.2 temporal variations and their influence on the coastline32
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Topic 1.1.4 Factors affecting coastal processes and landforms40
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JCL - Plate margins8
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Volcano JCL - E15 Case study28
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Earthquake JCL - Case study48
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1.1.3 - landforms and landscape systems20
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1.1.552
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1.1.647
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1.1.755
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1.1.823
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JCL Volcanoes2
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Geography fieldwork study61
