Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Alevelllll > Coastal Environment 1 > Flashcards

Coastal Environment 1 Flashcards

1
Q

What type of system is coastal systems

A

Open System- where energy and matter can be transferred from neighbouring systems as an input and to neighbouring systems as output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Components of coastal landscape system including inputs, processes and outputs

A

Inputs:
Kinetic, potential, thermal energy
Sediments from marine deposition, weathering and erosion from cliff

Processes: (Stores and Flows)
Weathering
Mass Movement
Erosion
Transportation
Deposition
Long shore drift

Beaches, sand dunes, bars

Output:
Marine erosion
Wind erosion from beaches and rock surfaces
Evaporation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is equilibrium

A

When input=output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Coasts example of equilibrium

A

Rate of sediment added to a beach equals the rate of sediment being removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What could disturb the equilibrium

A

Stores, Sea level rise, human intervention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What keeps coastal system in dynamic equilibrium

A

Negative and positive feedback loop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define negative feedback loop

A

Automatic response to change in system to restore equilibrium
Opposing force to counter changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Example of negative feedback loop in coastal system

A

When a beach is in dynamic equilibrium
During a storm, sediments get eroded away
Sediments deposited offshore forming offshore bars
Waves are forced to break before reaching the beach, dissipating energy and reduce further erosion
After the storm, normal wave conditions brings sediments back onto the beach
Beach is in dynamic equilibrium again

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define positive feedback loop

A

Enhances or amplifies changes, moving system away from equilibrium
Snow ball effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Example of positive feedback loop

A

Waves erodes away the cliff
The materials carry out further and faster erosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define Sediment Cell

A

Stretch of coastline and its associated nearshore areas where the movement of material are self contained
Closed System- no sediments can be transferred from one cell to another
In reality, can’t be completely sediment tight- due to wind and tidal currents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Example of sediment cell

A

Christchurch Bay, 5b
There are 11 cells around UK coast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Inputs, Processes, and Outputs of sediment cell

A

Input:
Sediments sources- rivers (80%) , cliff,

Processes:
Long shore drift
Erosion
Deposition
Transportation
Weathering
Wind
Currents

Output: (sinks of sediments)
Depositional Landforms- beaches, bars

Positive feedback loop- high energy waves during storms, removing sediments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Influence of wind speed, direction, and frequency on coastal landscape systems

A

Higher wind speed, longer fetch, larger the waves, and more energy
Onshore winds, blowing from the sea towards the land, more energy in waves
If wind blown in oblique angle, long shore drift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What energy does waves possess

A

Kinetic energy from the circular motion of water within the wave
Potential energy as a result from its position to the trough

P=H^2T
P= Energy
H= Wave height
T= Wave period- interval between wave crests

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Anatomy of Waves

A

Crest- highest surface part
Trough- lowest part
Wavelength- horizontal distance between two crests
Wave height- vertical distance between the crest and the trough
Fetch- distance over which the wind has blown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Development and breaking of waves

A

As waves enter shallow water (when the depth of water is half their wavelength), where water depth decreases, frictional drag with the sea bed slows waves down
This increases wave height, sharper crest and shorter wavelength, waves bunch up
Wave breaks when water depth is less than 1.3 times wave height
Water moves up the beach- Swash
Water drawn back after no more energy to move forward- backwash- due to gravity

18
Q

What is spilling wave

A

Steep waves breaking onto gently sloping beaches
Water spills forward

19
Q

What is plunging wave

A

Steep waves breaking onto steep beaches

20
Q

What is Surging Waves

A

Low angle waves on steep beaches

21
Q

Characteristics of Constructive waves

A

Low energy waves-spilling
Low frequency (6-8 per minute)
Low wave height (up to 100m)
Long wavelength
Swash > Backwash
-builds up beaches

22
Q

Characteristics of Destructive Waves

A

High energy waves
High wave height
High frequency (10-14 per minute)
Short wavelength
Backwash > Swash
-move sediments down the beach
-form storm beaches

23
Q

Explain wave refraction

A

Process by which waves break onto different shapes of coastline
Waves bend and refract due to variations in water depths
- in deeper areas, they break later
-low energy waves spill onto bays as most wave energy concentrated on headlands

24
Q

Define long shore drift

A

Where waves hit the shore at an oblique angle, causing lateral movement of sand and shingle along the beach

25
Influence of tides on coastal landscapes systems
Periodic rise and fall of the sea surface produced by the gravitational pull of the moon and the sun Moon pulls water towards it, creating high tide on both sides- the opposite side due to inertia Highest tide: Spring tide- Earth, moon, and sun are all aligned, gravitational pull is the strongest -high tidal range -2 times each lunar month Low tides when moon is at 90 degree angle to the earth Neap tide- when moon and sun are at right angle of each other -even lower than low tide Diurnal changes- 2 high tides and 2 low tides each day High tidal range- larger area for wave activity to occur Tides affect coastal erosion- low tidal range, e.g Mediterranean - lower wave energy and many cliff faces unaffected by marine processes -affects the type and rate at which landforms are created
26
Factors affecting tides
Gravitational effect- from the moon (more effect as its closer) from the sun (less effect as its further) Geomorphology of seabed and coastline- when width and depth of the sea decreases- funneling of water- much higher tidal range Same with estuaries Coriolis Effect- spinning of the earth Northern Hemisphere- water and tides to rotate clockwise around amphidromic point- forming gyre Southern Hemisphere- rotate anticlockwise
27
Influence of geology on coastal landscapes systems
Lithology- rock type More resistant rocks- erode and weathered slower Less resistant rocks- erode and weathered faster E.g clay’ Chalk and Limestone- susceptible to chemical weathering due to their calcium carbonate content- soluble to weak acids Structure: Micro scale- jointing, faulting in rocks- easily eroded and weathered- line of weakness Macro scale- concordant coastline- rocks lie parallel to the coastline- forms straight coastlines Discordant coastline- rocks lie perpendicular to the coastline- forms headlands and bays Angle of dip Landward dipping- steep cliff Seaward dipping- cliff following angle of dip
28
Define ocean currents
Movement of water in the ocean
29
Different types of ocean currents
Longshore currents Rip currents Upwelling
30
Longshore Current
Current of water running parallel to the shoreline Transport sediments parallel to the shoreline
31
Rip Currents
Strong currents moving away from the shoreline due tidal motions or waves breaking at right angles Occurs where there is huge differences in wage heights Created cusps on beaches, help perpetuate rip currents due to the narrow channelling flow
32
Upwelling
Global pattern of currents circulating in the ocean Deep, cold water rises to the surface when the warm water on top moves elsewhere
33
What do the warm ocean currents do
Transfer thermal energy from low latitudes towards the poles- affecting western facing coastal areas driven by onshore winds Heat the air above the water by convection- carry water inland Warm air gets saturated- precipitation E.g Barton-on-Sea on the Wessex coast Combined with permeable geology- mass movement Warm temperature- root growth weathering, and carbonation (acid rain + calcium carbonate)
34
What do cold ocean currents do
Move cold water from poles towards the equator E.g sub polar gyre- from arctic to NW of Scotland- lower temperature in coastal regions Driven by offshore winds- less impact on coastal regions
35
Explain Thermohaline Circulation
Makes up 90% of the ocean Move due to gravity and density forces Ocean water in polar regions sinks as it’s colder and denser with high salinity Draws in warmer water from Tropics to the surface Cold water rises in the Tropics, gets warmed again Affects sub-aerial processes
36
What affects Ocean currents
Primary forces- gravity, Coriolis (circular currents), solar heating, winds Secondary forces- solar heating- water to expand- water in equator is 8cm higher than higher latitudes- water wants to flow down the slope Wind- blowing on the surface push the water
37
What is a positive sediment budget
More material added than removed
38
Terrestrial source of sediments
Fluvial- weathering, mass movement, deposition Aeolian- deposition and LSD River- 80% of sediment comes from it
39
Offshore sources of sediments
Marine deposition
40
Human Sources of sediments
Beach Nourishment

Alevelllll (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions