2.1 Physical processes that shape the coast
2.1.1 Types of waves: constructive and destructive and wave refraction.
2.1.2 Coastal erosion: hydraulic action, corrosion, corrasion, attrition; transportation; deposition; longshore drift.
2.1.1 Types of waves: constructive and destructive and wave refraction.
2.1.2 Coastal erosion: hydraulic action, corrosion, corrasion, attrition; transportation; deposition; longshore drift.
2.1.1 Constructive and destructive waves & refraction.
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The coast is the name given to the zone where the land meets the sea/ocean. Coasts are shaped by the sea and the action of waves. The processes that take place are erosion, transportation and deposition. The action of waves The power of waves is one of the most significant forces of coastal change. *Waves are created by wind blowing over the surface of the sea. *As the wind blows over the sea, friction is created - producing a swell in the water. *The energy of the wind causes water particles to rotate inside the swell and this moves the wave forward. The size and energy of a wave is influenced by:
Task 1 - Click on the diagram to the right hand side to enlarge. Make a sketch of this in your workbook and label accordingly. Add an arrow to represent fetch too. Review Task 2 - Now watch the first 2.15 of the YouTube video above to reinforce what you have just learned about. Task 3 - Mix & Match Match the correct keyword to definition from the list underneath. Use your highlighter pen on each key word as they will be really important for your exam.
Task 4 - Watch the video about wave refraction to the right. Once complete, please complete the relevant section of your work booklet. Complete this task on the Task 5-6 booklet above. Swash and backwash. Watch the video to the right, and then check out this revision page. Task 5 - Using your worksheet, explain how the process works and draw a suitable diagram. Task 6 - There are two types of waves, constructive and destructive (deconstructive). i. Watch the YouTube video below and study the diagrams within the video. This site from the BBC is excellent. On your worksheet, make notes on destructive & constructive waves and create a sketch diagram to show the features of each types of wave. |
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2.1.2 Coastal Erosion.
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Task 1 - Watch the cliff collapse video in Cornwall, UK, to the right. This happens all the time around the world - the sea wins! It's not always caught on camera though. This has happened as a result of a number of erosional processes. We are going to learn about these next. Task 2 - Complete the worksheet above by using the information in this section. Coastal Erosion (types of erosion) Coasts being at the boundary of the land and the sea are extremely vulnerable to erosion. They are attacked by the immense power of the sea and the weather. The main ways that the sea erodes the coast are: Hydraulic Action: This is when sea water and air get trapped in cracks. The increasing pressure of the water and air cause the rocks to crack. Corrasion (abrasion): Rocks been thrown into the cliffs by waves and breaking off bits of the cliff. Corrosion (solution): The slight acidity of sea water causing bits of the cliff to dissolve. Attrition: Rocks, sand and stones being thrown into each other by the sea current and waves. Task 3- Watch the pretty bad IGCSE video filmed by someone familiar to IST students (to the right). What type of erosion can you see evidence of? How would this look in an examination? - Check out this video. Longshore Drift or LSD is an important process on every beach. It is the process by which beach material moves along the beach over time. If you painted a pebble bright pink, left it and came back one week later, the ocean waves will have moved it to a completely different part of the beach (updrift or downdrift).
Task 3 - Watch the video to the right and then complete the annotation task on the worksheet below. Before you draw on the movement direction, check out the clues on the image to work out the correct diagram (clue - the wooden groynes). |
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