Coasts

• What is a system?

  a set of interrelated objects comprising of components (stores) and links (processes) that are connected together to form a working unit or unified whole.
• What energy is available to the coastal landscape?

  kinetic, thermal, potential
• What allows geomorphic processes to shape the landscape?

  Energy (thermal, kinetic, potential)
• What are coastal landscape systems regarded as?

  Open systems
• Name the inputs of a coastal landscape system

  Kinetic energy from waves and wind.

  thermal energy from the heat of the sun.

  Potential energy from the position of rocks on slopes.

  Material from marine deposition, weathering and mass movement from cliffs.
• Name the outputs of a coastal landscape system

  marine and wind erosion from beaches and rock surfaces.

  evaporation
• Name the throughputs of the coastal landscape system

  Stores such as beach and nearshore sediment accumulations

  Flows (transfers) such as the movement of sediment along a beach through longshore drift
• What is equilibrium in a coastal landscape system?

  When a systems inputs and outputs are equal.
• Give an example of equilibrium in the coastal landscape system.

  The rate of sediment being added to a beach equalling the rate at which it is being removed.
• What is dynamic equilibrium?

  When an equilibrium is disturbed, the system undergoes self-regulation to correct these changes and restore the equilibrium.
• What is dynamic equilibrium an example of?

  Negative feedback
• What is a sediment cell?

  A sediment cell is a stretch of coastline and its associated nearshore area that is largely self-contained in terms of sediment supply and movement.
• What type of system is a sediment cell regarded as?

  A closed system
• What are the boundaries of sediment cells determined by?

  The topography
• What are the physical factors impacting the coastal landscape system?

  Wind

  Waves

  Geology (lithology and structure)

  Currents

  Tides
• How is wave energy created?

  By the frictional drag of winds moving over the surface of the ocean.
• What causes a wave to have more energy?

  Higher the wind speed and the longer the fetch creates a larger wave and as such more energy.
• What aeolian processes can wind carry out?

  Erosion, transportation, deposition.
• How many large sediment cells are there on the coast of england and wales?

  11
• How much taller and more powerful are Atlantic waves compared to channel waves

  8 times higher

  70 times more energy
• what’s the frequency of constructive waves?

  6 to 8 per minute
• what’s the frequency of destructive waves

  12 to 14 a minute
• What’s the max tidal range at the Severn Estuary?

  14 m
• Why does clay have a weak lithology?

  The bonds between particles that make up the rock are quite weak
• Why is basalt more resistant?

  Made up of dense interlocking crystals
• Name the components of structure

  Bedding

  Jointing

  Faulting
• Name a porous rock

  Chalk
• Name a way in which structure influences the coastline on a regional scale

  Rock outcrops - discordant and concordant coastlines
• Name the two different types of strata

  Horizontally bedded

  Landward-dipping strata
• What are rip currents caused by?

  tidal motion or by waves breaking at right angles to the shore
• How do rip currents modify the shore profile?

  Creating cusps ( regular and pointed arc pattern of sediment on a beach )
• Describe ocean currents

  Large scale phenomena, generated by the Earths rotation and by convection and are set in motion by the movement of winds across water surface
• How do terrestrial sources impact the coastal landscape system?

  major sources of sediment input to the sediment budget.
• In some locations how much % of coastal sediment comes from rivers?

  80%
• why is aeolian material usually very fine sand?

  Wind has less energy so can’t carry large particles like water can
• What brings sediment to the shore from offshore sources?

  Constructive waves via marine deposition.

  Tides and currents

  Wind blows sediment from exposed sandbars, dunes and beaches elsewhere along the coast
• How has human sources inputted coastal sediment into the system ?

  Beach nourishment
• How are coastal landforms developed?

  weathering - physical, biological, chemical

  Wave processes - erosion, deposition, transportation

  mass movement

  fluvial processes - erosion deposition and transportation

  aeolian processes - erosion deposition transportation
• name the processes of physical weathering

  Freeze thaw

  pressure release

  thermal expansion

  salt crystallisation
• During Freeze-thaw how much does the rock expand by when water enters the cracks/joints?

  10% causing it to split into pieces and break off