Introduction to Coasts - GCSE Course by Job Rafik

Key Terms

• Constructive Wave
• Destructive Waves
• Fetch
• Swash
• Backwash
• Longshore Drift
• Concordant Coastline
• Discordant Coastlines
• Bay
• Cove
• Beaches
• Deposition
• Clips and Erosion

Waves and Their Influence

• Waves significantly shape the UK's coastline.
• Causes of Waves:
  • Generated by wind blowing over sea surface.
  • Influenced by:
    • Duration of wind blowing.
    • Wind strength.
    • Distance wave travels (Fetch).
• Wave Movements:
  • Swash: Movement of waves up the beach.
  • Backwash: Movement of waves back down the beach.

Types of Waves

Destructive Waves

• Formed under stormy conditions.
• Larger and more powerful.
• High energy with long fetch.
• Stronger backwash than swash, leading to erosion.
• Characterized by:
  • High and steep shape.
  • Short length.

Constructive Waves

• Formed in calmer weather.
• Less energy compared to destructive waves.
• Deposit materials on shore.
• Stronger swash than backwash.
• Characterized by:
  • Long length and short height.
  • Smooth and almost flat appearance.

Longshore Drift

• Movement of sediment along the coast by wave action.
• Occurs when swash comes in at an angle and backwash goes straight out.
• Direction follows prevailing wind.
• Important to draw and annotate correctly in diagrams.

Coastal Formations

Concordant Coastlines

• Layers of different rock types parallel to the coast.
• Harder rock acts as a barrier to softer rock.
• Cove Formation:
  • Formed when a hard rock layer is breached.
  • Joints enlarge due to erosion.
  • Softer rock is eroded faster.
  • Example: Lulworth Cove, Dorset.

Discordant Coastlines

• Bands of rock types perpendicular to the coast.
• Formation of Headlands and Bays:
  • Headlands: Harder rock erodes slower.
  • Bays: Softer rock erodes quicker through hydraulic action, solution, and abrasion.

Cliffs

• Found along the coastline.
• Formation:
  • Soft rock erosion forms gentle slopes.
  • Hard rock creates steep cliffs.

Beaches

• Formed through deposition.
• Types: Sand, pebble, shingle, mud.
• Constructive waves build beaches.
• Beach Profile:
  • Sand beaches gently slope.
  • Shingle/pebble beaches have steeper profiles.
• Sediment transportation involves longshore drift.
• Larger sediment at the top due to constructive waves' inability to pull it back.