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Learning Objective: To discover and understand how waves shape the coast. Coastal process revision
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1.Unscramble the terms below: (4) atnrostpr - seriono - tpsodie - etiagehrnw - 2.Link the terms to the correct definition: (4) 3.Study video; describe and explain wave actions. Wearing away and removal of material by a moving force, such as a breaking wave. Breakdown and decay of rock by natural processes, without the involvement of any moving forces. Dropping of material that has being carried away by a moving force. Movement of material by rivers, waves and the wind. Transport Erosion Deposit Weathering Answers: / 10 http://www.bbc.co.uk/learningzone/clips/understanding-wave-formation/4018.html
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What effect does the length of the fetch has on coastal erosion ?
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Learning Objectives: To understand there are two types of waves (all) To be able to describe the landforms of the coastline (most)
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There are _____ types of w_____ that move towards the coast. Waves are produced by _____ and the longer it blows, the B_____ the waves tend to be. When waves break, ______ rushes ___ the B____ due to the energy from the wave. This is called the S_____. When the ______ has lost its _______ further up the beach it runs back down again, under ______. This is the B______sh. Big waves have lots of f_____ and energy and this means they have the _______ to carry out _________ of _________ or ______ on the ______. These are called ___________ ______. twoaves erosion coastdestructive power ackwa orce energy water wash eachup gravity igger wind beachesrocks waves
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C__________ w____ are _______. In calm _______s – without much _____ – the ______ are usually _______, _______ with ____ frequency. They don’t _______ with much ______ and they tend to add ______ and other ________ to the __________ by _________. The ______ is _______ than the _________ so sediment is _______ up the ______, helping to build it up. onstructive different condition aves windwaves sand break lowweaksmall coastlinesediment force deposition greater pushed swashbackwash beach
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Destructive Constructive 1. Study video and list examples of where destructive and constructive waves can be found. http://www.bbc.co.uk/learningzone/clips/coastal-erosion-and-landforms/9966.html
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Constructive Waves Strong Swash / Weak Backwash
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Strong backwash / Weak swash
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3. List differences and similarities between Destructive and Constructive waves. Wave height Wave energy Wave frequency Swash: Backwash Main process Constructive Destructive
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Annotate 7 landforms created by erosion Test:
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X HeadlandBay
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Wave-cut notch
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Learning Objective: To understand the factors affecting rates of cliff recession
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Revetments Coastal erosion Geology Clay Fetch Cliffs Holderness Recession
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Identify key features that has and will be affected by coastal erosion
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Complete the paragraph by adding the key terms at the bottom of your sheet: Erosion and retreat of coastal cliffs can happen at very different rates of change from over 1.8 metres per year as at Holderness, Yorkshire to very little. The rate of erosion and recession is due to the influence of factors such as geology formation and structure of rocks and coastal management as well as the Fetch. This is the distance of sea over which wind blows and waves move towards the coast.
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Coasts that face a major ocean; such as the South West coast of England facing the Atlantic Ocean have a very long fetch and the winds are strong and persistent. This produces destructive waves with high energy that can erode cliffs at rapid rates. The geology of South West England is another factor. These rocks are mainly granite which is a very resistant / hard rock eroding a few millimetres per year. At Holderness the very weak clay rocks have eroded at a high rate.
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A third factor that affects these rates is that of coastal management. Concrete sea walls as coastal defences protect weak rocks which results in a slower rate of erosion. When granite boulders are positioned before these weak cliffs to protect them they erode slowly and almost stop cliff recession.
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Erosioncoastalrecession geologymanagement Fetch windcoastSouth WestAtlanticOcean Longstrongpersistent destructivehighCliffs rapidgraniteresistant MillimetresHoldernessweak clayhighConcrete Defencesslowerprotect
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Low lying land and soft rocks Sea defences – Revetments built in 1960’s Reducing rate of erosion to cm per year In 1992 a survey predicted a 60 year erosion scale along the coast up to 2052. In 12 years the predicted 60 years erosion survey had eroded. That's 48 years sooner than expected!
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What impact is coastal erosion having on Happisburgh?
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How is Happisburgh defending itself?
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Learning Objective: To identify the different types of soft and hard engineering found along the coastline http://www.bbc.co.uk/news/uk-15547830http://www.bbc.co.uk/news/uk-15547830 (Landslip leaves 15 Barry caravans teetering over cliff)
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1. Identify 5 key terms linked to hard and soft engineering. These are examples of hard and soft engineering. 3. Advantages and Disadvantages of hard engineering. Advantages Disadvantages 1. Protects base of cliff 2. Land and buildings are protected 3. Prevents movement of longshore drift 4. Absorbs wave energy 5. Made of resistant material 1. Expensive to build 2. Restricts access to beach 3. Requires regular maintenance 4. Visual pollution 5. Other places along the coast loose their beach and natural defence
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4. Advantages and Disadvantages of soft engineering. Advantages Disadvantages 1. Natural appearance 2. Provides beach for tourists 3. Low maintenance costs 4. Natural process continues 5. Protects land and buildings 1. Sea continues to erode 2. Requires regular maintenance 3. Compensation payments to land and homeowners 4. Disruption to peoples lives and businesses 5. Dependant on hard engineering methods
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Complete the following definitions: Hard engineering is... Soft engineering is... Choose a method of coastal sea defence listing its advantages and disadvantages.
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Sea wall - RhylGroynes - BorthRip rap – Criccieth Revetments- Happisburgh Offshore reefs - Gulf of Mississippi
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Beach replenishment–Havant, U.K.Managed retreat, Tollesbury, Essex Cliff regrading, Milford-on-Sea, Hampshire
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