Theme 2. The natural environment 2. 1 Plate tectonics 2 Theme 2. The natural environment 2.1 Plate tectonics 2.2 Landforms and landscape processes 2.2.1 Weathering 2.2.2 River processes 2.2.3 Marine processes 2.3 Weather, climate and natural vegetation 2.3.1 Weather 2.3.2 Climate 2.3.3 Ecosystems You will be using the blue textbook at the back of the room (Cambridge IGCSE Geography Gary Chambers)– please add your name to this and keep it until I return – hand your old textbook back to Ms Rios.

What do we remember about marine processes (coasts!) L/O: To revise the key processes and landforms created at the coast. Answers: LOAD FETCH EROSION DEPOSITION EXTRA: YOU NEED MOVEMENT FOR EROSION AND WEATHERING IS BREAKING DOWN ROCK THROUGH CHEMICALS, PLANTS, ANIMALS OR CHANGE IN WEATHER! A little quiz: Answer in FULL sentences! Remember rivers? What do we call the material carried by a river? The distance the wind travels across the surface of the sea is called the _________? (Clue: you may say this to a dog!) Erosion / deposition occurs when the sea is wearing away the land. Erosion / deposition is occurring when the sea is adding to the land with rocks and pebbles. A cliff is an example of where erosion / deposition has occurred A beach is an example of where erosion / deposition has occurred EXTRA! Erosion is different to weathering because …….

Types of erosion – you need this for rivers and coasts so LEARN IT! Task: Complete the sentences in task 2 on page 76! 6 minutes! NO MORE!

Constructive and destructive waves! Swash Backwash Remember standing on the beach in Matalascañas? The water ran gently over our toes and then rushed back to sea – we called these waves, DESTRUCTIVE waves because the backwash was stronger than the swash! The land was being destroyed (or eroded) by the waves. If the land was being added to (the load was being deposited) then the swash is stronger than the backwash so they would be CONTRUCTIVE waves!

Where does a coastline get eroded or constructed? Erosion: Along the coast the land is more eroded where there is softer rock (sedimentary rock) and less eroded where there is harder rock! Deposition: The coast gets added to when the sea deposits its load to create a number of different land forms – this is occurs because of long shore drift (explain the Ms Rios what this is!) Headlands are formed where rock is the most resistant! Bays are formed where the rock is softer and erodes more easily.

What are sub-aerial processes? The coast is the narrow zone between the land and the sea. It is worth remembering that the landscape will be influenced by processes on the land as well as the sea. Sub-aerial processes include weathering (from the plants, animals and rain) and mass movement (from the wind). These processes operate on the cliff face to weaken it and make it easier for coastal erosion. https://www.youtube.com/watch?v=siejKY0HEtY

Tasks: These must be finished this lesson or will be EXTRA homework Tasks: These must be finished this lesson or will be EXTRA homework! 1) Label the three diagrams (on this slide and the next) with the labels provided – use page 77 if you do not remember – I HAVE DONE THE FIRST DIAGRAM Erosional features A notch (crack)is created in the cliff The notch erodes where the sea hits leaving a wave cut platform (a piece of rock hanging over the sea) A line of weakness called a fault appears in the rock This fault increases in size until it becomes a cave The waves erode the cave until the water breaks through the other side creating an arch The roof of the arch falls into the sea creating a stack The stack is eroded away to form a stump

Read the description and match up the labels to the different parts of the diagram Depositional features Sand spit: long narrow stretch of sand with one end attached to the land Sand bar: when a spit is stretched along the bay and links two headlands Tombolo: when a spit or sand bar joins up with an offshore island Barrier islands: sandy islands that run parallel to the coast Sand dunes: formed by wind blowing dry sand from the beach inland and making piles of sand where plants grow. Saltmarsh: The area behind the spit which is sheltered and where sea salt is deposited and plants can grow.

Key Words Waves are the result of the wind blowing over the sea. They break as they approach land. Swash and backwash describe the movement of a wave on the beach. Fetch is the distance that the wind has travelled. Sub-aerial processes such as weathering and mass movement occur on the cliff face. Coastal processes of erosion include hydraulic action, attrition, corrosion and solution. Landforms created by erosion include headlands and bays, caves, arches, stacks and stumps. Longshore drift is a method of coastal transport. Landforms created by deposition include beaches, spits, tombolos and bars.

How can beaches be protected from erosion or movement? Groynes are wooden barriers at right angles to the beach. They last 30-40 years and are a couple of metres tall Groynes slow longshore drift and encourage the build up of material creating a wider beach. The beach absorbs wave energy slowing down cliff erosion, protecting buildings and roads.

Sea wall

Curved Sea wall

Rock Armour