Coasts Flashcards
(14 cards)
1
Q
Is the coast an open or closed system?
A
- the coast is an open system
2
Q
Inputs at the coast
A
Marine
- waves
- tides
- salt spray
Atmosphere
- sun
- wind speed and direction
- air pressure
Human
- pollution
- recreation
- settlement
- defences
3
Q
Outputs at the coast
A
- ocean currents
- rip tides
- sediment transfer
- evaporation
4
Q
Stores at the coast
A
- beaches
- salt marshes
- sand dunes
- spits
- headlands and bays
- bars and tombolos
5
Q
Transfers/flows at the coast
A
- weathering
- erosion (hydraulic action, abrasion, attrition, solution)
- transportation (suspension, saltation, traction, solution)
- deposition
- mass movement
6
Q
What’s dynamic equilibrium?
A
- inputs and outputs are balanced
- coastal systems are generally in dynamic equilibrium
7
Q
What’s negative feedback?
A
- when a change in the system nullifies the effect of the change
- e.g. beach eroded, cliffs behind exposed to waves, sediment eroded from cliffs deposited back onto beach, beach builds back up
8
Q
What’s positive feedback?
A
- when a change in the system amplifies the effect of the change
9
Q
What are the sources of sediment at the coast?
A
- rivers
- cliff erosion
- wind
- glaciers
- offshore
- longshore drift
10
Q
What’s the sediment budget?
A
- uses data of inputs, outputs, stores and transfers
- difference between the amount of sediment that enters and leaves the coastal system
- if more enters, the sediment budget is positive and the coastline builds outwards
- if more leaves. the sediment budget is negative and the coastline retreats
11
Q
What are sediment cells?
A
- self-contained sections of the coastline between two headlands
- each cell is a closed system
- in dynamic equilibrium
- also called littoral cells
12
Q
What are the sources of energy at the coast?
A
- wind
- waves
- tides
- currents
- sun
13
Q
Energy Source - Wind
A
- created by air moving from areas of high pressure to areas of low pressure
- during storms, the pressure gradient is high so winds can be strong
- strong winds generate powerful waves
- prevailing wind causes higher-energy waves
14
Q
Energy Source - Waves
A
