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Exam Q • Including keywords where possible, describe and explain how erosion can influence the coast. You may use a diagram. [3marks]

Coastal geomorphic processes and geology

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GCSE Geography Coastal geomorphic processes and geology for OCR B controlled assessment

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  • 1. Exam Q Including keywords where possible, describe and explain how erosion can influence the coast. You may use a diagram. [3marks]

2. Recap: What are the 4 Types of coastal erosion? 3. Erosion is. the wearing away of materials by one of four processes: Corrosion = chemical reactions of salt water weakening rocks like an acid Attrition = Pebbles hitting into each other or into cliffs making rocks break and get smaller and rounder Abrasion = sand paper effect. Waves throwing small stones and pebbles at cliffs and beaches to smooth the material Hydraulic Action = Power of the water forcing its way into cracks and weaknesses in rocks, splitting apart 4. Recap : landforms 5. The main landforms created by erosion are 6. Headlands and Bays 7. Wave cut notches and platforms 8. Wave-cut platform Burgh Island, Devon Wave cut platform Southerndown, South Wales. 9. Beaches develop where the supply of sediment exceeds loss through backwash and longshore drift. Beaches are usually distinguished as either Shingle or Sand Shingle beaches are free draining so there is little backwash of material to sea. As a consequence, they are usually steeper. 10. How was this landform created? 11. Spits and Bars Where there is a change in the coastline e.g. a headland or an estuary mouth, longshore drift may continue to deposit sediments into the sea forming a spit. 12. Local currents and changes in wind direction may curve the end of the spit landwards creating a hooked tip. The presence of the estuary discharging river water into the sea prevents the spit from developing into a bar. Such a feature is known as a recurved spit wind 13. Exam Q How does geology influence the speed of erosion at the coast? [2marks] 14. The geology of the coast affects how much it is eroded. More resistant rocks (e.g. chalk) erode more slowly than less resistant rocks (e.g. clay, limestone) This gives us BAYS And HEADLANDS 15. The Jurassic Coast The Jurassic Coast is a section of coastline in Southern England that shows geology over millions of years. The coastline first began forming 250million years ago Dorset shows the geology of the Jurassic period, between 200-140million years ago 16. What about waves? 17. If you were a wave, and you wanted to grow big and strong so you could knock the UKs block off, which direction would you come from? Why? 18. Waves There are two main types of waves: Constructive vs Destructive 19. Exam Q Describe and explain how constructive and destructive waves work. Use keywords or examples where possible. [4marks] 20. How do waves influence landforms? Longshore drift 21. Longshore drift http://www.youtube.com/watch?v=29o5ntbxjJs 22. Long-shore drift (LSD) 23. Exam Q: With the use of a diagram, explain the process and effects of longshore drift, and how it can be managed [6marks] 24. Reminder about Grid References 25. Constructive or Destructive coastline? What evidence from the map?