Coastal Systems: Waves, Tides and Sediment Cells Flashcards
What is Dynamic Equilibrium?
When equilibrium is disturbed the system undergoes self regulation and changes its form in order to restore the equilibrium.
What are throughputs?
Throughputs consist of stores including beach and nearshore sediment accumulations and flows such as the movement of sediment along a beach by longshore drift.
What is a closed system?
A closed system suggests that no sediment is transferred from one cell to another. However it is unlikely that sediment cells are completely closed.
What determines the boundaries of sediment cells?
Give one example.
The topography and shape of the coastline. Example = Land’s End - large natural barrier.
What is the jetstream?
High speed winds in the upper atmosphere that determine weather.
What is the predominant wind direction?
South West
Name 5 physical variables in a coastal system
Climate/weather patterns/seasons Wave type and strength Wind direction Fetch length and direction Tidal range and flow Currents Geology of Coastline Concordant/discordant Availability of sediment from marine, coastal and fluvial sources Erosion and weathering processes
Name 5 human influences on a coastal system
Coastal engineering and management Groynes Sea Walls Disruption of sediment supply Dredging River dams Cliff protection Blocking structure Jetties Harbour Walls
What causes waves?
Waves are caused by the surface of the sea exerting frictional frag on the lowest layer of the wind. Higher layers of the wind then move faster over the lower levels and fall forward, pushing down on the sea surface, creating a wave.
What does the height of a wave depend on?
The height of a wave depends on: the fetch the strength of the wind the duration of the wind sea depth
