Theme b

• Constructive waves

  General action: Adds material to the shore
• Constructive wave

  Size: Low + far apart
• Constructive Wave

  Frequency: less frequent 6-9 per minute
• Constructive waves

  Season: Common in summer
• Constructive waves

  Effects: strong swash weak backwash pushes small pebbles of the beach causes deposition which builds up the coast.
• Destructive waves
• Destructive wave general action

  Erode or Take away material from the shore
• Destructive Wave

  Size: Highland and close together
• Destructive waves

  Frequency: Frequent up to 15 a minute
• Destructive wave

  Season: common in winter (storm waves)
• Destructive waves

  Effects: stronger back wash than swash drags sand + pebbles out to sea.

  Erodes the coast
• Coastal processes Erosion
• Coastal processes -Transportation

  Long shore drift
• Longshore drift

  If, however, waves approach the shore at an angle the swash carries material of the beach at the same angle but the backwash returns it straight back to the waters edge because of gravity this is shown in the diagram B below this zigzag movement of sand or pebbles along the coast is called long shore drift
• HACA processes 
• Hydraulic action

  The power of the sea can physically wash away soft rocks like boulder and clay. Under storm conditions with strong waves, hundreds of tons of seawater can hit the coast. Also air can be trapped and small cracks within a cliff when a wave breaks against it. This compressed air can widen the cracks, eventually leading to sections of cliff breaking away from the main cliff face.
• Attrition

  Particles being transported by the sea hit against one another reducing their size and making them rounded, just like in rivers.
• Corrosion

  Seawater can dissolve away the rocks from the seabed or cliffs. This process is especially effective on limestone coasts, and can create spectacular caves. It is also known as corrosion
• Abrasion

  Sandpapering effect. Went away hits the coast, it throws sand and pebbles against the cliff.. These knock off small parts of the cliff and caused undercutting.
• Coastal landforms
• Formation of headlands

  Headlands are formed when the sea attacks a section of coast with alternating bands of hard and soft rock.

  The bands of soft rock, such as sound and clay, erode more quickly than those of more resistant rock, such as chalk.

  This leaves a section of land jutting out into the sea called a headland.

  The areas where soft rock has eroded away next to the headland, are called base
• Formation of cliffs and wave cut platforms

  1. Soft rock erodes quickly and forms gentle sloping cliffs

  2. Hard rock is more resistant and forms steep sloping cliffs

  3. Wave cut platform is a wide gently sloping surface found at the foot of a cliff
• The sea attacks the base of the cliff


  Between the high and low watermark
• Formation of a wave notch

  1. Erosional processes such as abrasion and hydraulic action

  2. Notch is a dent in the cliff usually at the level of high tide
• As the notch increases in size

  The cliff becomes unstable and collapses, leading to the retreat of the cliff face
• Retreat of the cliff face

  1. The backwash carries away the eroded material

  2. Leaving a wave cut platform

  3. The process repeats and the cliff continues to retreat
• Formation of caves arches stacks and stumps
• Formation of caves, arches, stacks and stumps

  1. Cracks or widened in the headlowned through the erosional processes of hydraulic action and abrasion

  2. Waves continue to grind away up the crack, it begins to open up to form a cave

  3. Cave becomes larger and eventually breaks through the headland to form an arch

  4. Best of the arch continually becomes wider through further erosion until it's rough becomes too heavy and collapses into the sea, leaving a stack (an isolated collum of rock)

  5. Stack is undercut at the base until it collapses to form a stomp
• Caves, arches, stacks and stumps

  • Erosional features commonly found on a headland
• Caves, arches, stacks and stomps are erosional features that are commonly found on a headland
• Formation of a beach

  When waves are constructive, they deposit the load they carry onto the shore. This is called deposition. This afternoon happens and I sheltered area between two headlands.
• Beaches can be made from sand or shingle. On Sunday beaches, the backwash removed all material, making a gentle sloping beach.
• On shingle beaches, the wave energy is reduced due to the stones absorbing energy through percolation so the back wash is not very powerful resulting in a steep beach.
• Formation of spits

  Spits are created by deposition of material. What is it? Aspect is an extended stretch of a beach. Material that pro jacks are to see and it joined to the mainland at one end.
• How is it formed?

  Spits are formed where the prevailing wind blows act and angle to the coastline resulting in long shore drift.
• 1. Long short drift moves material along the coastline. (erosion is taken place further back along the coastline.)
• 2. Deposited material starts to build up where the coastline changes direction.
• 3. Spit starts to form when the material is deposited.
• 4. Overtime the spit grows and develops are hook if wind direction changes.
• 5. Waves can't get past a spit which creates a sheltered area where slit is deposited and mod flats or salt marches form.