Coastal landscapes as Systems Flashcards
What drives the coastal system?
Wave energy
What type of system are coastal systems?
Open Systems - Energy and sediment are transferred in and out from neighbouring systems
What is stored and transferred through a coastal system?
Energy
Sediment
What are the inputs into Coastal Systems?
Energy & Sediment
What are examples of Energy Inputs into coastal systems?
Kinetic energy e.g wind & waves
Thermal energy e.g the sun
Potential energy e.g from the position of Material on the slope
What are the examples of Sediment inputs into Coastal systems?
Material from erosion, weathering and mass movement
What are Processes in a Coastal system?
Erosion, transportation and deposition
What are the Outputs in a coastal system?
Marine & Aeolian erosion
What is equilibrium in the System?
Inputs = Outputs
What happen when the Coastal system’s equilibrium is disturbed?
Self-regulation takes place
How do wave types vary during summer vs winter?
Summer - constructive waves - Swash > Backwash
Winter - destructive waves - Backwash > Swash
How is energy transferred during longshore drift?
The Aeolian energy from the wind transfers to the waves
Then the energy is transferred forwards until the wave breaks
This energy is the used for erosion or transportation
How does the wind influence the Coastal landscape systems?
Wind is a source of energy for erosion and transportation
Energy of waves are dependent on the: strength of wind, the duration and the length of the fetch
What is Fetch?
it is the distance to the next nearest land mass
so the distance a wave travels
Why is wave height important & how do you calculate it?
Most important in determining wave energy
Explain how breaking waves form
Water molecules have circular movement with forward movement of energy
As waves reach shallower waters they will slow due to friction with the sea floor
The wavelength decreases and successive waves will start to bunch up - The deepest part of the wave slows more than the top of the wave
The wave steepens as the crest advances ahead of the base - resulting in a breaking wave
What is a spring tide?
It is when the moon, sun and Earth are all aligned resulting in a stronger gravitational pull
happens 2x a month
tidal range is longest
How does the moon influence tides?
The moon pulls water towards it and creating a high tide
What is tidal range?
The vertical difference between the high tide and the succeeding low tide
What happens when tidal range is low?
wave action is restricted to a narrow area
smaller concentration of erosional processes
Often see shore platforms form
What happens when the tidal range is higher?
the area of land exposed to the effect of the waves is much higher
What is lithology?
The physical and chemical composition of rocks
What are the 3 types of rocks?
Sedimentary
Igneous
Metamorphic
How resistant are the different types of lithology?
Sedimentary - Low resistance to erosion, weathering and mass movement as the bonds are weak - e.g clay, limestone
Igneous/Metamorphic - High resistance to erosion, weathering and mass movement, with interlocking crystals e.g. basalts, slates.
What is Concordant coastlines?
When there is the same rock type all the way along the coastline exposed and therefore eroded at the same rate
What are Discordant coastlines?
When there are layers of soft and hard rock exposed to the coastline creating different rates of erosion
How do ocean currents impact the coastal landscape?
They transfer heat energy around the world, which influences the climate and therefore weathering processes
How does a rip current form?
It forms when 2 backwashes form to create and extra strong backwash pull on the sediment
