2.b High energy coastline - Coastal landforms are inter-related and together make up characteristic landscapes

Question 1

How does wind and wave affect Skomer?

Answer 1

• Rising sea levels increased erosion and cut off island from main land
• Hit by destructive waves due to exposure to Atlantic Ocean
• Waves have a large fetch (from Caribbean) on the South West
• The islands South West coastline is much more rugged due to being in direction of prevailing wind than the North West coastline which has a linear coastline as it is sheltered
• Due to wave and wind energy constantly eroding the coastline and leading to obvious coastal landforms such as geo’s

Question 2

How does tides affect Skomer?

Answer 2

• Large tidal range of 7m
• Low tide; 3am, 4pm
• High tide: 9am, 10pm
• Large intertidal zone = erosion during high tide and deposition during low tide
• Strong tidal currents = erosion contributing to the creation of wave-cut platforms and other coastal features. Transports sediment, shaping it’s coastline and beaches
• Arguably most significant factor in the erosion of NW fault that became Bull Hole

Question 3

How do ocean currents and currents affect Skomer?

Answer 3

• North Atlantic drift gives waves more energy and so erodes coastlines
• Currents is same throughout = not very significant

Question 4

How does geology affect The Wick?

Answer 4

• Structure: Started as a Geo and originally eroded linearly due to a fault = structure was originally the most important
  
  • Lithology: Basalt on the west side is less susceptible to erosion due to it’s crystalline structure, while on the east side the sedimentary rock (sandstone) is arranged in bedding planes which have a seaward angle of dip - more likely to have landslides
    the basalt will suffer from rockfall in seconds, sandstone suffers slumping in millennia

Question 5

How does geology affect Bull Hole?

Answer 5

• A geo made up of basalts (same rock)
  
  • Erodes at the same rate (linearly)
  • Structure most important

Question 6

How does geology affect The Neck?

Answer 6

• Neck is made up of all the same material therefore is not affected by lithology
  
  • Weakness in the rocks (faults and joints)
  • Areas with fault lines are eroded at a faster rate, therefore, no longer a straight coastline
  • Structure is more important than lithology

Question 7

Sediment system on west side of Skomer

Answer 7

• Cliff Sediment -> rockfall -> moved away by sea

Question 8

Sediment system on east side of Skomer

Answer 8

Cliff sediment -> slump -> Transported by sea and deposited on coastline

Question 9

Sediment system on The Wick of Skomer

Answer 9

• Cliff sediment -> Rockfall -> transported by SW winds

Question 10

Energy system on west side of Skomer?

Answer 10

• GPE + Kinetic -> Friction + Sound -> Lost to system

Question 11

Energy system on east side of Skomer?

Answer 11

GPE + Kinetic (less) -> friction -> Kinetic energy + lost to system

Question 12

Energy system on The Wick of Skomer

Answer 12

• GPE -> Kinetic -> Wave energy

Question 13

Sediment Transport

Answer 13

• Mainly swash-aligned transport of sediment due to wave energy being perpendicular to the shoreline = limits LSD but facilitates deposition in sheltered bays
• LSD is limited due to swash aligned transport, however, can occur in localised areas
• Aeolian transport mainly moves sediment further onland, but can move a small amount along the shore in some instances