8 marker: Flows of energy in coastal systems

Explain the flows of energy and material through coastal systems. (8)

what is a system?

• A set of interrelated objects comprising components (stores) and processes (links) that are connected together to form a working unit or unified whole.

• Coastal landscape systems store & transfer energy and material on time scale that can vary from a few days to a millennia.

Flows of energy and material in a system: AO1

• The energy is coastal systems may be kinetic, potential or thermal.

• This energy enables work to be carried out by the natural geomorphic processes that shape the landscape.

• The material found in a coastal landscape system is predominantly the sediment found on beaches, in estuaries and in shallow waters of the nearshore zone.

Inputs into a coastal system?

• Kinetic energy from wind and waves.

• Thermal energy from the heat of the sun.

• Potential energy from the position of material on slopes – material from marine deposition, weathering & mass movement from cliffs.

Outputs?

Marine & wind erosion from beaches and rock surfaces – evaporation.

Processes?

• Consist of stores – beaches and nearshore sediment accumulations.

• Flows & transfers e.g. movement of sediment along a beach by LSD

Equillibrium?

• When systems inputs & outputs are equal.

• This could happen when the rate at which sediment in being added to the beach = the rate which sediment is being removed from the beach – thus remaining the same size.

• When equilibrium is disturbed – system undergoes self-regulation & changes its form in order to restore the equilibrium.

• Known as dynamic equilibrium – system produces its own response to the disturbance – example of negative feedback.