Lesson 2: Waves and Coastal Landforms Objective: To explain how waves are formed and their impacts at the coastline To be able to describe some of the landforms created by hard and soft rock

Starter Which type of marine erosion goes with these definitions. Just number 1-4 in your book. 1. When rock fragments grind and bash into each other down into smaller smoother pebbles, shingle and finally sand which is later deposited as beaches. 4. Lots of sea water crashes against the land, and air and water are trapped and compressed in rock surface cracks. When the sea moves away again, the air expands explosively weakening the rocks, enlarging the cracks and breaking pieces off. 3. Involves chemical action of sea on rock. If the rock is limestone, it dissolves in the sea-water – some sea salts can also react with certain rocks and cause them to rot. 2. Is cause by broken rock fragments battering the land, cliffs etc. and breaking off other pieces of rock. 1= attrition 2= corrasion 3= solution 4= hydraulic action

Waves and the Coastlines Waves are constant Waves have three affects on the coast They cause Erosion They Deposit eroded material They Transport eroded material

Waves The height of the waves depend on how long and far the wind has been blowing over the sea and how strong it is. This is called the fetch

What happens below the water as waves move?

What happens when waves reach the coast?

Wave Types We know what waves can do to the cliffs but did you know that there are 2 different types of waves and they can BUILD or DESTROY beaches. Destructive waves these destroy beaches by taking away the sediment- also known as winter waves Constructive waves these build beaches by depositing sediment on the beach- also known as summer waves

Task You will need to understand how waves are formed and effect the coastline. Answer the questions below to check your understanding of this. The sea causes three processes to occur on the coastline, name these and give a description of each. What are the three characteristics that effect the size of a wave and which combination creates the largest waves? Explain the difference between swash and backwash. Explain how constructive waves construct coastline and destructive waves destroy it.

Landforms at the Coast Marine and Sub-Ariel erosion cause several landforms and erosional features at the coast. Headlands and Bays Caves, arches, stacks and stumps Cliff slumping Wave cut notches and platforms Longshore drift

Headland and Bay formation

Caves, arches, stacks and stumps Source: http://www.geography.learnontheinternet.co.uk/topics/waves.html

Wave-cut notch and platform

Wave-cut notch and platform

Task: Make a copy of this diagram in your book, remember to include a title. 1 3 2 7 6 5 4

Longshore Drift- process of deposition and transportation

Let’s try the Long Shore Drift dance Up the beach at an angle = Swash Straight down the beach= Backwash

Task: describe and explain the process of longshore drift (6) Task: describe and explain the process of longshore drift (6). You may use a diagram to help.

Plenary Lets play Geography Pictionary! You will be given a feature or process and you need to draw it for the others to guess.