influence of physical processes

• outline how wind influences coastal landscapes

  • a source of energy for coastal erosion and sediment transportation
  • created by thermal energy which creates kinetic energy
• outline how waves influence coastal landscapes

  • transports and deposits sediment
  • creates energy for erosion
  • generated by frictional drag of wind over the water surface.
• energy and size of a wave depends on...

  • wind strength
  • wind duration
  • water depth = how much energy is put into the wave
  • fetch (distance) of the wave
• describe the process of wave propagation

  ALWAYS SAY a wave propagates instead of forms

  1. a wave propagates in the deep ocean and moves towards the shore
  2. as the wave propagates out of the area it was generated, it becomes a swell wave
  3. when the wave base hits the sea floor, it breaks and becomes a translatory wave
• define swell wave

  smooth ocean wave that travels a distance from its area of generation
• define translatory wave

  transfers both water and energy
• define constructive wave

  • AKA spilling breaker
  • builds the beach
  • stronger swash than backwash
  • finer sand and flat beach
• define destructive wave

  • AKA plunging breaker
  • removes sediment
  • stronger backwash
  • when the energy increases = marine erosion accelerates:

  1. creates steeper beach bc wave can travel further before it loses energy and deposits sediment.
  2. coarse sediment bc waves can transfer more and larger sediment.
• formula for calculating: amount of energy in a wave in deep water

  P = H²T
• outline how tides influence coastal landscapes

  • cyclical pattern = most coasts have 2 high and 2 low tides per day, approximately every 6 hours and 13 mins.
  • tidal patterns created by variation in gravitational pull of sun and moon on ocean surface = as the moon orbits the earth, it alters the tidal range.
• define tidal range


  the difference between a high and low tide
• define spring tide


  when the gravitational pull of the sun and moon combines = creates an extreme tidal range. for example the highest high and lowest low.
• define neap tide

  when the gravitational pull go the sun and moon are opposite = creates a small tidal range.
• define lithology 


  the composition of rock and its resistance to weathering and erosion
• outline SEDIMENTARY rock - types of geology

  example = sandstone and limestone

  • forms under the ocean from dead animals by consolidation of sediment layers under heat and pressure.
  • porous = the least resistant to erosion
• outline IGNEOUS rock - types of geology

  example = granite and basalt

  • forms under extreme heat and pressure which removes imperfections = increases resistance.
  • created by crystallisation = solidification of magma
• outline METAMORPHIC rock - types of geology

  example = slate

  • forms under extreme heat and pressure which removes imperfections = increases resistance.
  • created by recrystallisation in solid state of new minerals.
  • most resistant to erosion
• outline how geological structure influences coastal landscapes

  • it influences the rate of erosion = cliffs made from strata with different resistances
  • responsible for concordant and discordant coasts
• define folds - geological structure

  formed by layers of rock being bent and folded, created by pressure of tectonic forces

  
• define joints - geological structure

  fractures in rocks where no displacement has occurred

  
• define faults - geological structure

  large scale fractures and displacements created between 2 blocks of rocks, created by tectonic forces, which allows them to move relative to each other

  
• define concordant coasts - geology

  forms where rock strata runs parallel to coast
• define discordant coasts - geology

  forms where rock strata is aligned at an angle to coastline = forming headlands and bays
• define vertical dip (cliff) - geology

  rock strata angled vertically

  • erosion type = wave cut notches + weathering and mass movement of jointed strata
• define seaward dip (cliff) - geology

  rock strata angled downwards diagonally towards the sea

  • vulnerable to rock falling
  • frequent mass movement and landslides of cliff collapse due to marine undercutting.
• define landward dip (cliff) - geology

  rock strata angled downwards diagonally towards the land

  • creates a steep profile with few rock falls
• outline surface ocean currents - ocean currents

  • caused mainly by wind and weather patterns
  • defined mainly by atmospheric circulation
  • influenced by gravitational tides
• outline deep ocean currents - ocean currents

  caused by changes in water density

  1. cold water freezes and concentrates salt
  2. downwelling occurs = saline water sinks = occurs at poles
  3. deep ocean currents move towards equator
  4. upwelling occurs = cold water moves to surface = occurs at tropics
  5. warm surface = more circulation, waves, evaporation