Coastal Landscapes

• Hydraulic Action is the force exerted by water as it hits an object
• Abrasion is when sediment carried by waves rub against rocks or cliffs causing them to wear away
• Attrition is where rocks collide with one another due to hydraulic action, this causes smaller pieces to break off from larger ones.
• Solution occurs when rock dissolves into solution (water) which then carries the material away.
• Saltation occurs when small pebbles bounce along the sea bed, they can be thrown up onto the beach during stormy conditions.
• Long shore drift is the movement of sediment down a beach due to waves.
• Constructive waves carry sediment onto a beach. Strong swash, weak backwash.

  Destructive waves carry sediment away from the beach. Weak swash, strong backwash.
• Soft engineering.

  Beach nourishment - sand off shore is deposited onto coast

  Dune regeneration - marram grass planted to stabilize + develop dunes. Effective buffer

  Dune fencing - fences around existing dunes to encourage new ones
• Hard engineering

  Groynes - rock or timber. right angle to beach. Trap sediment, enlarge beach. Wide beach = less dmg

  Rock armour - piles of boulders which absorb wave energy

  Gabions - Wire cages full of rocks. Support cliff. Buffer

  Sea walls - concrete or rock. Curved to deflect waves
• issues with management.

  interfere with natural processes - cause dmg elsewhere

  spoil landscape

  increased visitors increase litter
• Mass movement

  Rockfall - rock falls off cliff

  Mudflow - saturated soil sides down slope

  Landslide - large chunks of rock slide downhill

  Rotational slip - Saturated soil slumps down curved surface
• Freeze thaw

  water enters crack

  water freezes and expands. Crack widens

  Ice melts. Water goes deeper into crack. repeat
• Biological weathering

  plants and animals burrowing enter rock cracks.

  Roots grow and gaps widen.

  Rock breaks
• Chemical weathering

  rain / seawater can be acidic. Erodes / dissolves rock over time
• Spits

  sediment carried along beach by LSD

  at a change in the coastline deposition occurs

  Long ridge of material deposited

  hooked end can form with wind change
• Headlands and bays

  Bands of soft and hard rock along coast

  Soft rock erode quickly

  Hard bands of rock erode slowly

  Leaves a dip in cliff. Headlands stick out (hard rock), bays curve in (soft)
• Formation of stumps

  cracks in headland are widened by hydraulic action

  big cracks become caves

  waves erode both sides of rock and cut through. Arch

  Waves continue to erode rock. When the roof can no longer be supported, it collapses. Stack

  stack is undercut and eroded. Base becomes a stump
• Wave cut platforms

  Sea attacks cliff base

  wave cut notch formed by erosion

  Notch increases, cliff collapses

  backwash carries eroded material. As its rolled its flattened. Wave cut platform with many layers