Erosion

• Marine erosion is direct erosion by the sea
• Subaerial erosion is erosion and weathering by wind, rain and frosts
• What are the erosion processes operating at the coast?

  1. wave pounding
  2. hydraulic pressure
  3. abrasion
  4. attrition
  5. corrosion
  6. sub ariel
  7. human activity
• What are factors effecting rate of erosion?

  1. breaking point of water
  2. wave steepness
  3. depth of sea, length and direction of fetch
  4. supply of beach material
  5. beach width
  6. rock resistance
• What is wave pounding?


  steep waves have sizeable energy so when they break at the base of a cliff or sea wall they can generate shock waves up to 30 tonnes per sq m. Some parts of England need to replace sea walls 25 years after being built due to wave pounding.
• What is hydraulic pressure?


  when a parcel of air is trapped and compressed. This either happens in a joint in a cliff or between a breaking wave and a cliff. This increase in pressure over time will weaken and break off rocks or could damage sea defences.
• What is abrasion?


  it is the wearing away of cliffs due to sand, shingle, and boulders being hurled against them by waves. It is the most effective form of erosion and is the most rapid in coastal areas exposed to storm waves.