1. Coastal Processes

2. Waves created by friction of wind on water.
Top of wave = Crest
Bottom of wave =Trough
Wave Length = Crest to Crest

4. When waves move into shallow water they break as the top of the wave moves faster than the lower half...

5. Construction vs. Destruction
When a wave breaks, water is washed up the beach - this is called the swash.
Then the water runs back down the beach - this is called the backwash.
With a destructive wave, the backwash is stronger than the swash.
With a constructive wave, the swash is stronger than the backwash.

6. Destructive [take sand away]

7. Constructive [add sand]

8. Coastal Erosion LOOK FAMILIAR???!!! RIVERS???!!!!
Hydraulic Action: The force of the water breaks away the coast.
Abrasion: Debris (such as sand) interactions with coasts.
Attrition: Large rocks interaction with coasts.
Corrosion: All water is a little acidic; some rocks are dissolved (eg. Limestone)
LOOK FAMILIAR???!!! RIVERS???!!!!

9. Erosion Process
Undercutting: Wave action + erosion along shoreline creates cliff and then wears down until collapse creating some new features.

12. Features Caves – weakest rocks erode first and eventually collapse
Bays – erosion of softer rocks and large area is created.
Headlands – areas where harder rock resists erosion.
Tunnels – when waves eventually erode through headland.
Arch – erosion through headland continues to grow.

13. Stacks – when arch collapses.
Wave-Cut Platform – the final remainder of a headland that has been eroded away.

16. Longshore drift
Waves can approach the coast at an angle because of the direction of the wind.
Swash, angled, brings sand onto the beach +
Backwash, removes it straight back =
Long Shore Drift: movement of sand along a beach

18. Deposition
Spit: Sand carried away by long shore drift; long narrow ridge of sand
Tombolo – If a spit connects an island to the mainland.

21. Groynes – Barriers built to stop long-shore drift.

22. In-land Coastal Processes
Estuaries: Mix of fresh and salt water
Fjords: Deep U shaped river valleys that go all the way to the ocean.