Summary
Coastal deposition involves the process where waves lose energy and deposit sediment, forming landforms such as beaches, spits, bars, and sand dunes. This process is influenced by wave energy, sediment supply, and coastal shape.
- Coastal Deposition — occurs when waves lose energy and drop sediment. Example: Happens in sheltered areas like bays.
- Constructive Waves — low height, long wavelength, strong swash, weak backwash. Example: Build up beaches by depositing sediment.
- Destructive Waves — high height, short wavelength, weak swash, strong backwash. Example: Erode beaches by removing sediment.
- Longshore Drift — zigzag movement of sediment along the coast. Example: Waves approach at an angle, backwash flows straight down.
- Spit — long, narrow ridge of sand extending into the sea. Example: Formed by longshore drift, often with a recurved end.
- Bar — ridge of sand or shingle across a bay. Example: Connects two headlands or joins an island to the mainland.
- Sand Dunes — hills of sand formed by wind deposition. Example: Stabilized by vegetation, found behind beaches.
Exam Tips
Key Definitions to Remember
- Deposition
- Constructive Wave
- Destructive Wave
- Longshore Drift
- Beach
- Spit
- Bar
- Barrier Bar
- Tombolo
- Sand Dunes
- Swash
- Backwash
Common Confusions
- Difference between constructive and destructive waves
- How spits and bars are formed
Typical Exam Questions
- Explain how a spit is formed? Longshore drift, change in coastline direction, deposition, recurved end.
- Compare the characteristics of constructive and destructive waves? Differences in height, frequency, swash/backwash strength.
- Explain the difference between a barrier bar and a tombolo? Barrier bar connects headlands, tombolo connects island to mainland.
What Examiners Usually Test
- Understanding of wave types and their effects
- Processes of coastal deposition and landform formation
- Ability to describe and explain the formation of specific coastal features