Geography - UK Coastal Landscape

• What are the two types of weathering? Give examples of them

  • Mechanical - Freeze thaw weathering
  • Chemical - Carbonation
• Describe how freeze thaw weathering works

  • Water enters a rock and freezes in sub 0 conditions
  • As the water freezes, it expands, putting pressure on the rock
  • This pressure causes the rock to crack and/or break
  • This continues until the rock breaks or splits
• Describe how carbonation works

  • Rain water has dissolved carbon dioxide within it
  • This carbon dioxide cause the water to form weak carbonic acid
  • As it rains, this acid gets into rocks
  • This acid can then dissolve rocks that contain calcium carbonate (e.g. Limestone)
• What is mass movement?

  The shifting of loose material and rocks down a slope
• What are the 3 types of mass movement?

  Slides, Slumps, Rockfalls
• Describe slides

  Material shifts in a straight line down a slope
• Describe slumps

  Material rotates down a curved slope
• Describe rockfalls

  Material breaks up and falls down a slope
• What are the two types of waves?

  Constructive, Destructive
• What effects the power of a wave?

  The length of the fetch
• What is fetch?

  The distance wind travels across water
• What is swash?

  Water moving up a beach
• What is backwash?

  Water moving down a beach
• Describe constructive waves

  • Low frequency
  • Short
  • Long wavelength
  • Powerful swash
  • Weak backwash
  • Deposit material
• Describe destructive waves

  • High frequency
  • Tall
  • Steep
  • Short wavelength
  • Weak swash
  • Strong backwash
  • Remove material
• What is erosion?

  The wearing away of land caused by water
• What are the 3 coastal types of erosion?

  Hydraulic power, abrasion, attrition
• Describe hydraulic power

  The force of water breaking / damaging rocks
• Describe abrasion

  Rocks rubbing against each other, causing them to break apart
• Describe attrition

  Rocks colliding and becoming more rounded
• What is longshore drift?

  The movement of eroded sediment along the coast in a zig-zag motion in the direction of the prevailing wind.
• What is transportation?

  The movement of eroded material
• What are the 4 types of transportation?

  Traction, suspension, saltation, solution
• Describe traction

  Large rocks are pushed along the sea bed by the force of the water
• Describe suspension

  Small rock particles are carried along in the water
• Describe saltation

  Pebble sized rocks are bounced along the sea bed by the force of the water.
• Describe solution

  Soluble materials are dissolved into the water and carried along
• What is deposition?

  The dumping of material when water loses its energy
• What are the two types of coastline?

  Concordant, discordant
• Describe a concordant coastline

  Alternating bands of hard rock and soft rock parallel to the coast
• Describe a discordant coastline

  Alternating bands of hard rock and soft rock perpendicular to the coast
• Describe how headlands and bays are formed

  • At a discordant coastline erosion occurs
  • Hard rock is eroded slower than soft rock
  • Soft rock is eroded faster so forms a bay with less eroded hard rock headland on either side
• Describe how headlands are eroded into caves, arches, stacks and stumps

  • Hard rocks headlands contain cracks
  • Waves crash into the headland and erode the crack through hydraulic power and abrasion
  • The crack enlarges and forms a cave
  • The cave is eroded an forms a arch
  • Erosion and weathering collapse the crack and form a stack
  • The base of the stack is eroded and forms a stump
• Describe how waves erode cliffs to form wave cut platforms

  • Erosion occurs where waves hit the side of a cliff
  • Continuous erosion form a wave cut notch
  • Above the wave cut notch, rock become unstable and collapses
  • Material is cleared leaving a wave cut platform
• Describe how waves form beaches through deposition

  • Constructive waves deposit material along a coastline.
  • Sand beaches are formed by low energy waves and are flat and wide.
  • Shingle beaches are formed by high energy waves and are steep and narrow.
• Describe how deposition can form spits

  • Longshore drift at a sharp bend on the coast carries on into the sea, rather than on the coast
  • Material is deposited into the sea and forms a spit
  • Changes in the direction of the prevailing wind can cause a recurved end
  • The recurved end leaves a sheltered area where mud flats or salt marshes can form
• Describe how a bar is formed by deposition

  • At a headland, longshore drift can cut across a bay, joining to the other headland
  • The bar cuts of the bay from the sea, forming a lagoon, that could dry out
• Describe how sand dunes are formed by deposition

  • Wind blows material up a beach
  • This material is caught by obstacles and forms an embryo dune
  • Vegetations colonize the embryo dune and stabilize the dune using their roots
  • Sand accumulates forming foredunes and mature dunes
  • Dune slacks form between dunes
• What are the two types of coastal defence strategies?

  • Hard engineering
  • Soft engineering
• What is hard engineering?

  Man made structures built to control the flow of the sea and prevent flooding or erosion