geography

• What are the 2 types of waves?

  Constructive and Destructive
• Fetch

  How far a wave has travelled
• Wave formation

  1. Wind blows over the sea

  2. Creates waves
• Wave size and energy

  • Depends on fetch
  • Strength of wind
  • How long wind has been blowing
• Swash

  The water flowing towards a beach when a wave breaks
• Backwash

  The movement of water down the beach
• Destructive waves

  • Weak swash
  • Strong backwash
  • Remove sediment from beach
  • Steep and close together
• Constructive waves

  • Strong swash
  • Weak backwash
  • Bring sediment to build up beach
  • Low and further apart
• Sediment

  Small fragments of rock and soil that form layers
• Weathering


  Processes that break down and remove material from the coast
• Erosion, mass movement and weathering


  • Break down and remove material from the coast
  • Material is moved along the coastline by the sea and deposited when there is energy loss
• Freeze-thaw weathering


  Occurs when rocks are porous or permeable, allowing water to enter cracks. When temperatures drop, the water freezes and expands causing the crack to widen. The ice melts and water makes its way deeper into the cracks. The process repeats until the rock splits entirely.
• Biological weathering


  Plants and animals can have an effect on rocks. Roots burrow down, weakening the structure of the rock until it breaks away. Plant roots can get into small cracks in the rock and as they grow, the cracks become larger, causing small pieces of rock to break away.
• Chemical weathering


  Rainwater and seawater can be a weak acid. If a coastline is made up of rocks such as limestone or chalk, over time they can become dissolved by the acid in the water.
• What is the process of Freeze-thaw weathering

  A) water enters crack

  B) water freezes ane expands the rock

  C) ice melts and water goes deeper into crack

  D) process reapeats until rock splits

  
• Mass movement

  The downhill movement of sediment that moves because of gravity
• Types of mass movement

  • Rockfall
  • Mudflow
  • Landslide
  • Rotational slip
• Rockfall

  • Bits of rock fall off the cliff face, usually due to freeze-thaw weathering
• Mudflow

  • Saturated soil (soil filled with water) flows down a slope
• Landslide

  • Large blocks of rock slide downhill
• Rotational slip

  • Saturated soil slumps down a curved surface
• Erosion

  Processes called erosion, mass movement and weathering break down and remove material from the coast. The material is moved along the coastline by the sea and deposited when there is energy loss.
• Destructive waves


  • Waves which remove material from the beach. The swash is weaker than the backwash.
• Hydraulic action

  • The sheer power of the waves as they smash against the cliff. Air becomes trapped in the cracks in the rock and causes the rock to break apart.
• Abrasion

  • Pebbles grind along a rock platform, much like sandpaper. Over time the rock becomes smooth.
• Attrition


  • Rocks that the sea is carrying knock against each other. They break apart to become smaller and more rounded.
• Solution


  • Sea water dissolves certain types of rocks. In the UK, chalk and limestone cliffs are prone to this type of erosion.
• Destructive waves are responsible for erosion on the coastline.
• Erosion


  Processes that break down and remove material from the coast
• Mass movement

  Processes that break down and remove material from the coast
• Erosion


  Processes that break down and remove material from the coast
• Mass movement


  Processes that break down and remove material from the coast
• Weathering

  Processes that break down and remove material from the coast
• Transportation


  The material is moved along the coastline by the sea and deposited when there is energy loss
• Deposition


  The material is moved along the coastline by the sea and deposited when there is energy loss
• Ways beach material can be moved

  • Solution
  • Suspension
  • Saltation
  • Traction
• Solution

  Minerals in rocks like chalk and limestone are dissolved in sea water and then carried in solution
• Suspension

  Small particles such as silts and clays are suspended in the flow of the water
• Saltation

  Small pieces of shingle or large sand grains are bounced along the sea bed
• Traction

  Pebbles and larger material are rolled along the sea bed