Physical Geography - Coasts

• What is isostatic change?


  Isostatic change is a local change in sea level caused by the land either sinking or rising.
• What is the main cause of isostatic change?


  Normally, it is due to glaciers melting.
• What are the four main causes of isostatic change?


  1. Post-glacial adjustment
  2. Accretion
  3. Lowering of the water table
  4. Folding of sedimentary rock
• What happens during post-glacial adjustment?


  Heavy icy sheets weigh land down, and when the ice melts, the land rebounds to a higher level.
• How does accretion contribute to isostatic change?


  Areas of net deposition cause land to build up, making sea levels appear lower.
• What causes the land to sink in the context of isostatic change?


  Lowering of the water table or increased deposition weighs down the sediment, making the land sink.
• How does volcanic activity affect isostatic change?


  Lava and ash from volcanoes increase the height of the land relative to sea level.
• What is a drowned river valley?


  A drowned river valley is formed when sea levels rise and flood river valleys, leaving only high land visible.
• What is an example of a drowned river valley?

  Fal in Cornwall.
• What is a fjord?


  A fjord is a drowned glacial valley that is submerged as sea levels rise.
• Where can many fjords be found?

  Norway.
• What are Dalmatian coasts?


  Dalmatian coasts form when parallel valleys are flooded by rising sea levels, leaving the tops as islands.
• What is a famous example of Dalmatian coasts?


  Croatia.
• What are submergent landforms?


  • Form when eustatic rise in sea level occurs faster than isostatic rebound.
  • Water floods the land and fills up landforms.
• What is eustatic change?


  Eustatic change is global and occurs when the sea level changes.
• What factors can cause eustatic change?


  Warming of the oceans causing thermal expansion and more water being added to the oceans.
• How does isostatic recovery occur?


  As ice melts, the reduced weight causes the land to rise.
• How do isostatic and eustatic changes differ?


  Isostatic change is local, while eustatic change is global.
• What happens to the land during glaciation?


  The immense weight of the ice causes the land to subside.
• What occurs at the end of glacial periods?


  The reduced weight of the ice causes the land to rise.
• What are the main concerns about using hard engineering techniques to protect the coast?


  They interrupt natural systems and reduce sediment input, affecting beach size and features.
• How does slowing down coastal erosion impact the coastal system?


  It reduces sediment input, which has implications for beach size and transfers to neighboring sub-systems.
• What is a consequence of hard engineering techniques for certain groups along the coast?


  The protective benefit for some groups often comes at the expense of others further along the coast.
• What are some examples of hard engineering structures used for coastal protection?


  • Groynes
  • Sea Walls
  • Rip Rap/Rock armour
  • Revetments
  • Offshore Breakwater
• How do groynes function in coastal protection?


  They are built perpendicular to the shore to trap sediment transported by longshore drift.
• What is the purpose of sea walls in coastal protection?


  They absorb and reflect wave energy with a curved or stepped surface.
• What is rip rap or rock armour used for?

  It consists of large boulders that reduce wave energy by causing waves to bounce between surfaces.
• What are revetments designed to do?

  They are sloped structures that break up wave energy.
• What is the function of an offshore breakwater?


  It is a rock barrier that breaks waves and dissipates energy before they reach the coast.
• What are the advantages of using hard engineering techniques for coastal protection?

  • Not as expensive as other structures
  • Builds up the beach, improving tourism
  • Highly effective
  • Creates walkways for tourism
  • Cost-effective compared to other strategies
  • Effective away from the beach
• What are the disadvantages of hard engineering techniques for coastal protection?

  • Causes sediment starvation further along the coast
  • Can be unattractive and intrusive
  • Requires significant maintenance
  • Very expensive to build and maintain
  • Rocks can be intrusive to local geology
  • Can create navigation barriers in harbors
• What is the primary difference between soft engineering and hard engineering?


  Soft engineering works with natural processes and materials.
• How can soft engineering methods help with sea level change and coastal erosion?


  They can be integral to strategies like developing marshes.
• What are the methods of soft engineering mentioned in the study material?


  • Beach nourishment/replenishment
  • Cliff regrading and drainage
  • Dune stabilisation
  • Marsh creation
• What is beach nourishment?


  It involves adding sand or shingle to widen a beach.
• What is one advantage of beach nourishment?


  It looks very natural and increases tourism.
• What is a disadvantage of beach nourishment?


  It requires constant maintenance due to erosion and longshore drift.
• What is cliff regrading and drainage?


  It reduces the angle of the cliff to stabilize the slope and drains water to prevent mass movement.
• What is dune stabilisation?


  It involves planting species like Marram grass to bind the dunes and absorb wave energy.
• What is marsh creation in the context of soft engineering?


  It allows land to be flooded by the sea to create a salt marsh that absorbs wave energy.