ship wreck coast - high energy system

• outline key details

  • south west coast of Melbourne, Australia
  • a high energy system
  • stretches 130 km along Great Ocean Road = from Port Fairy to Cape Otway
  • over 600 shipwrecks believed to have occurred between 1700 - 1900s = ships following the Clipper Route from England.
• outline the geology

  coastline made of Port Campbell limestone

  • irregular structure = each layer of cliff has a different resistance, depends on amount of calcium carbonate in it
  • cliff profile = younger strata at the top, older at bottom.
  • more calcium carbonate in the younger strata = more resistant
  • less calcium carbonate is older = less resistant
• outline waves - energy input

  • wave height = max 5 m
  • wave period = every 12 seconds
  • mean spring tide range = small. Not as high as waves because it gets shallower (the continental shelf absorbs most of the energy)
  • waves dont hit the land head on
• outline wind and waves - energy input

  cyclones occur in the Indian and Southern oceans

  • affects Great Ocean Road for about 300 days a year
  • waves can travel up to 1000 km = long fetch = more KE
  • rarely have a direct hit on the southern coast
• evolution of the coastline

  • sea level rose between 6000 - 18000 years ago = this coastline has been eroding and changing for over 6000 years and is constantly changing
  • rate of erosion = 2 cm / year = creates caves, arches, stacks, stumps, geos
• name the 4 landforms

  1. Port campbell limestone = cliff
  2. Twelve Apostles = stacks/stumps
  3. London Bridge = arch
  4. Loch and Gorge = geos
• outline the Twelve Apostles - landforms

  • stacks and stumps made of limestone
  • up to 45 m high
  • created by constant erosion of cliffs
  • erosion began 10 - 20 million years ago from constant waves and winds
• outline London Bridge - landforms

  • offshore natural arch near Port Campbell
  • made of limestone
  • created by gradual erosion from extreme weather conditions
  • collapsed in 1990 = part of the bridge fell into the ocean = bridge isolated from the mainland
• outline Loch and Gorge - landforms

  • geos
  • made of limestone = high rate of erosion