Lesson Focus: What processes are shaping the coastline? What: Understand the four processes of erosion How: Create a table to compare processes of erosion Why: To be able to explain what affects the shape of our coastline
Connect: Look at the following pictures. What do you think has happened?
Activate: What do the key terms mean for the coast unit?
Copy out the definitions and fill in the missing words. If you finish early, draw a sketch next to each key term to help you remember it.
wearing away sea coast deposited sand 1. Deposition – This is where material carried by the sea is dropped and ________ 2. Transportation – This is where material such as ____ and pebbles are carried by the _____ 3. Erosion – This is the ________ ______ and breaking up of rock along the _____. There are 4 main types of erosion.
Watch the video and start to complete the table Name of erosion
Diagram
Description
These definitions to help you complete your table: Attrition Material carried by the waves bump into each other and so are smoothed and broken down into smaller particles. Hydraulic action This process involves the force of water against the coast. The waves enter cracks (faults) in the coastline and compress the air within the crack. When the wave retreats, the air in the crack expands quickly causing a minor explosion. This process is repeated continuously. Corrosion This is the chemical action of sea water. The acids in the salt water slowly dissolve rocks on the coast. Limestone and chalk are particularly prone to this process. Abrasion/Corrasion This is the process by which the coast is worn down by material carried by the waves. Waves throw these particles against the rock, sometimes at high velocity.
What does all this erosion do to the coastline?
Headland
Bay
How do beaches form?
Which part of the cliff will erode faster and why?
Plan view
wave attack This is the headland which is made from more resistant rock than the bay.
This is the bay which is made from less resistant rock.
Which part of the cliff will erode faster and why? 1. Sketch your own copy of this diagram into your book 2. Annotate your diagram, you must include the following key terms: • • • • •
Wave attack Headland Bay More Resistant Rock Less Resistant Rock
Now, write a paragraph answering the question above. Try to use your key terms from today and some from last lesson.
• What problem does this photo show? • Who will be affected by this? • Can you think of any solutions to this issues?
REFLECTION
Coastal Kung Fu! http://www.youtube.com/watch?v=kqLsCdr6kiI