1.1: What is a coastal system and what are the dynamics of coastal environments?
The coastal system is one of inputs and outputs. There are 2 systems:
- The cliff system with inputs compromising the sub-aerial processes of weathering and the atmospheric processes of wind erosion; a throughput compromising cliff mass movement of falls, slips and slumps; and an output of sediment at the base of the cliff DEPOSITED or trasnported by marine processes.
- The beach system with an input of sediment from longshore drift (LSD), the cliff and offshore, a throughput of LSD and an output of LSD and destrive WAVES carrying sediment offshore.
- Areas of coasts are usually defined by headlands (a narrow piece of land that projects from a coastline into the sea) and bays (a broad inlet of the sea where the land curves inwards) in which marine processes are largely confined.
- This is acheived when inputs = outputs. The relationship constantly changes due to erosion, transport and deposition.
Constructive and Destructive waves:
- 6-8 waves per minute.
- Swash is stronger than backwash.
- They create, low flat and gentle waves.
- Form beach ridges and berms.
- 10-14 waves per minute.
- Backwash is stronger than swash.
- Combs down material to create a var.
- High, steep waves.
Most beaches experience the alternating action of…