Flashcards in Coasts Deck (26):
What are coastal zones
Dynamic environment a with distributive landscapes formed by the interaction of a range of wind, marine and terrestrial processes
How much of the worlds population live on coastal plains
About 50%, with over 59% living within 150km of the sea
What kind of systems are coastal environments
Example of feedback in a coastal system
Increased deposition on a beach but there is no corresponding change in the amount of sediment removed from the beach, then the beach features may change and the equilibrium is upset
What are inputs into an open coastal system
Geology of the coastline
Sea level change
Transfers in an open coastal landscape
Wind and water transport
Components in an open coastal system
Erosional landforms and landscapes.
Depositional landforms and landscapes.
Outputs in an open coastal system
Dissipation of wave energy.
Accumulation of sediment above the tidal limit.
Sediment removed beyond local sediment cells.
Example of a negative feedback mechanism in a coastal environment
A beach in dynamic equilibrium.
Sediment is erodes from the beach during a storm.
Sediment is deposited offshore forming an offshore bar.
Waves now forced to break before reaching the beach disposing their energy and reducing further erosion when they reach the beach.
When the storm calms, normal wave conditions rework sediments from the offshore bar back to the beach.
What do some negative feedback mechanism act to do
Stabilise coastal morphology and maintain a dynamic equilibrium
What kind of landscape is a coastal landscape
What do coastal landscapes consist of
A constantly changing assemblage or erosion and depositional landforms; they are the result of continuous change in the elements of a coastal system
What do the processes operating in coastal systems that continually shape the coastal landforms create
Distinctive landscape features
What does the coastline itself consist of
A series of different zones where specific conditions prevail that depend on factors such as tides, wave action and the depth of the sea
What are the 5 different zones in a coastline
Where is the backshore
The area between the high water mark (HWM) and the landward limit of marine activity
When does changes to the backshore usually take place
Only during storm activity
Where is the foreshore
The area lying between the HWM and the low water mark (LWM).
What is the most important zone for marine processes in times that are not influenced by storm activity
Where is the inshore
The area between the LWM and the point where waves cease to have any influence on the land beneath them
Where is offshore
The area behind the point where waves cease to impact upon the seabed and in which activity is limited to deposition of sediments
Where is the nearshore
The area extending seaward from the HWM to the area where waves begin to break
What 3 zones are included in the nearshore
What is the swash zone
The area where a turbulent layer of water washes up the beach following the breaking of a wave
What is the surf zone
The area between the point where waves break, forming a foamy, bubbly surface, and where the waves then move up the beach as swash in the swash zone