the coastal system Flashcards
what type of system is the coastal system?
open- it interacts strongly with other systems e.g sediment from rivers can alter sea levels
what is feedback?
can be positive or negative- increasing or decreasing inputs and outputs and enabling equilibrium
how does the coastal system interact with other earth systems?
- sediment movement and deposition from rock cycle
- biogenic aspects (shells)
- atmospheric cycle- wind causes weathering, creates waves
examples of inputs
precipitation, wind, fluvial sediment
examples of flows/transfers
erosion, evaporation, mass movement, longshore drift
examples of outputs
evaporation, ocean currents, riptides, wave cut platforms
examples of stores and components
sand dunes, beaches, bays, spits, headlands, bars
examples of feedback
coastal management can increase coastal erosion elsewhere, mass movement decreases cliff foot erosion as it is more protected
factors influencing the coastline
terrestrial, marine processes, human intervention, atmospheric
terrestrial intervention
tectonics, sub aerial processes, supply of sediment, fluvial processes, glaciations
marine processes
wave shape/size, fetch, wave direction, sea level change, tides, biotic features (reefs)
human intervention
sea defences, tourism and recreation, industrial and residential development, pollution, conservation
atmospheric
temperature, precipitation, global warming, solar energy, winds
what is a dynamic equilibrium?
when inputs and outputs of energy and matter balance
what is the equilibrium affected by?
supply of sand, energy of waves, sea level changes, location of the shoreline
what are landforms?
individual features which are created by coastal processes
what are landscapes?
the entire area of sea, coastline and immediate land behind sea front, within the landscape are characteristic landforms
explain why some areas of the UK are subject to powerful waves whilst others are not
areas such as cornwall and south wales are located on a shoreline surrounded by a large expanse of sea so waves hitting these beaches have a large fetch as the wind has a greater distance to blow over and more time to gather energy. however areas like london or brighton do not experience powerful waves as the fetch distance is small creating smaller waves
what does the tidal range dictate
how long wave processes can act on a cliff face for with a small range meaning they are focused on the same area for longer and capable of more erosion
what is the incoming tide called
flood current
what is the out coming tide called
ebb current
sediment cells in the UK
there are 11, divided into sub cells
transfers in a sediment call
LSD, winds and currents
sinks in a sediment cell
beaches, sand dunes, offshore bars