Coasts as Natural Systems Introduction Flashcards
Is the coast an open system?
Yes
What does an open system mean?
Matter (sand) and energy (wind/waves) can be transferred
What are the inputs of a coastal system?
Energy from waves, tides, sea currents and wind
What are the flows of a coastal system?
Transportation by wind or water
Erosional/ depositional processes
What are the stores in a coastal system?
Depositional / erosional landforms
What are the outputs of a coastal system?
Accumulation of sediment
Dissipation of wave energy
What is an example of a negative feedback mechanism within a coastal system?
A beach is in dynamic equilibrium
Sediment eroded from beach during storm
Sediment is deposited offshore forming an offshore bar
Wave energy is dissipated by bar before reaching beach - reducing erosion power
When storm passes, waves move sediment back
What does the example of negative feedback demonstrate?
There has been a state of change which has nullified, returning back to dynamic equilibrium
What does the entire coastal zone consist of?
Backshore, Forshore, Inshore, Offshore
What is the backshore zone?
Between high water mark and landward limit of marine activity
Changes only during storms
Not really affected by day to day coastal process
What is the foreshore zone?
Area between the high water mark and low water mark
Most important zone for marine activity
Where most the processes take place
Where we see the most change
What is the inshore zone?
Area between the low water mark and point where waves cease to have any influence on the land
What is the offshore zone?
Not on land anymore
Beyond the point where waves will cease to have any impact on the sea floor
What is the nearshore zone?
Consists of both the inshore and foreshore zone
Swash zone, breaker zone, and surf zone
What is the swash zone?
Turbulent layer of water washes up beach after wave breaks - frothy water
