What is a coast? Information for learners
Some of us live close to the sea and we can say we live 'at the coast'. But what does this mean and what will you find in this area?
The area between the land and the sea is called the coast and because of the constant movement of the water, the shape of the coast can change over time because of erosion.
- Explain the word 'erosion' in your own words and give a few examples.
- Learn more about different 'land forms' on earth.
In the area of the coast you will find different features like beaches and cliffs and sand dunes and at some places also a harbor. People like to build resorts next to the sea where you can go on holiday and have some fun in the sun and sea.
- Find pictures of each of these different features mentioned above.
The water of the sea does not only cause erosion, but it will also transports the broken pieces of shells and rocks up and down the coast where it will the 'deposit' (put it down) on the beach.
- What have you found on the beach that the sea had left there?
- Draw a picture of different sea shells or find pictures of it - also remember to add the names.
Depending on the type of rocks that are by the sea, they will form different land forms because of erosion. Some rocks like limestone, will for cliffs and others that are soft will erode and form bays.
- Find pictures of the different types of erosion on rocks that can be caused by the sea.
- Have a look at the video on 'coastline erosion' and answer the questions.
- What is the reason why the shape of rocks will differ from day to day?
- What besides from water causes erosion?
- What is 'coastal erosion'?
- Why can this erosion be 'bad' at the coast?
You have now learned what impact the waves can have on the coast, but did you know there are different types of waves?
If you watch the sea you will see that the wave breaks and the water goes onto the beach - I am sure that if you have ever been on the beach you would have played and run away from this water coming onto the beach. This is called the 'swash'.
If the water the runs back into the sea, it is called the 'backwash'.
If the force of the water that comes out on the beach is stronger than the water that runs back, we call is a 'constructive' wave.
If it is the other way round it is called a 'destructive' wave.
The wave height of the constructive wave will be lower than that of the destructive wave and the constructive wave will cause a wide and flat area on the beach, where the destructive wave will cause steep areas.
- Read more for extra information on coasts and certain processes taking place http://www.onegeology.org/extra/kids/earthprocesses/coasts.html
- For enrichment you can have a look at the worksheet and do you own research to find the answers (you do not have to do this, it is actually for the higher grades, but if you like a challenge, go for it) http://docs.wixstatic.com/ugd/5cd6ef_e180e178105f4c9483f84c87233ce1e3.pdf