The Coastal System Flashcards
Define an input in terms of coastal systems.
When energy/matter enters the system. Eg: wind and waves
Define an output in terms of the coastal system.
When energy/matter leaves the system.
Eg: when sediment is washed away to Sea.
Define a flow/transfer in terms of the coastal system.
When matter/energy is moved from one store to another. Eg: transportation and deposition.
Define a store in terms of the coastal system.
Where matter/energy is held. Eg: a beach.
Define dynamic equilibrium in terms of coastal systems.
When inputs and outputs are balanced.
Define negative feedback in terms of the coastal system.
When changes to the system have the opposite effect.
Eg: beach is eroded leaving cliff exposed
more sediment from cliff
beach will grow in size
Define positive feedback in terms of the coastal system.
When a change in the system causes other changes to amplify.
Eg:
Storm causes higher levels of erosion.
=sand dune is breached and broken
=Easier to erode
How is wind a source of the coastal system?
Created by air moving between high pressure and low pressure. Wind can become very strong causing high energy waves.
How are waves a source in the coastal system?
Created by wind blowing over the surface of the sea. Water washing up the beach= swash, water washing back= backwash.
What are the two types of wave?
Constructive and destructive
Describe the features of a constructive wave.
Low frequency (6-8 waves per minute)
Low and long
Powerful swash and weak backwash
Describe the features of a destructive wave.
High frequency( 10-14 waves per minute)
High and steep
Strong backwash
What are tides?
The periodic rise and fall of the ocean surface caused by gravitational pull. They affect the position that waves break on the beach.
What is a current and how is it a source of energy in the coastal system?
The general flow of water in one direction caused by wind or variations in water temperature.
They move material along the coast.
Describe a high energy coastline.
A coastline that receives high inputs of energy (large powerful waves) that are caused by strong winds and long fetches.
Tend to have rocky landforms and sandy coves.
Higher rate of erosion.
