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COASTS The Coast is.......................... MASS MOVEMENT This is where the coastline is altered because of LAND processes. 1. Mudflow 2. Rockfall.

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Presentation on theme: "COASTS The Coast is.......................... MASS MOVEMENT This is where the coastline is altered because of LAND processes. 1. Mudflow 2. Rockfall."— Presentation transcript:

1 COASTS The Coast is.........................

2 MASS MOVEMENT This is where the coastline is altered because of LAND processes. 1. Mudflow 2. Rockfall

3 MASS MOVEMENT This is where the coastline is altered because of LAND processes. 3. Landslide 4. Rotation Slip

4 1. Mechanical Weathering: Freeze – Thaw Rocks are broken down by the action of ice Types of Weathering

5 2.Chemical Weathering This is called SOLUTION. As sugar dissolves in tea, some rocks dissolve in rainwater. Some alkaline rocks (chalk and limestone) are attacked by a process called CARBONATION which is acidic rainfall dissolving them.

6 3. Biological Weathering This is where rocks are broken down by the action of burrowing animals and growing plants Roots of trees can create great pressure and rocks can be split apart

7 Explain how weathering can erode the coastline (4 marks)

8 Coastal Processes: from the sea acting on the coast Erosion Transportation Deposition

9 Types of Wave: 1) Destructive – results in features/landforms of erosion

10 Types of Wave: 2) Constructive – result in features/landforms of deposition

11 Forms of Coastal Erosion: 1. Corrasion – waves throw sand and pebbles at a cliff and wear it away.

12 2. Attrition – stones and pebbles smash into each other and break into small pieces, eventually becoming sand.

13 3. Solution – certain rock types (eg. chalk) react with sea water and dissolve.

14 4. Hydraulic Action – force of waves crashing into cliffs, air gets trapped in cracks making pressure which cracks the rock.

15 Explain how the sea can erode the coastline (4 marks)

16 A process of Transportation – Traction Pebbles roll along the bottom of the sea bed.

17 A process of Transportation – Saltation Pebbles bounce on the bottom of the sea bed.

18 A process of Transportation – Suspension Smaller pebbles are carried in the water. Not touching the seabed.

19 A process of Transportation – Solution Particles are dissolved in the water and transported

20 Why do we get headlands and bays? Headlands Bays

21 Hard rock Soft rock

22 Explain the formation of Headlands and Bays (4 marks)

23 Coastal Processes: from the sea acting on the coast Erosion Transportation Deposition

24 Longshore Drift GROYNE

25 Draw a labelled diagram to show the process of longshore drift (4 marks)

26 Why was geology important in the formation of Lulworth cove? Softest Rock Hardest Rock

27 What coastal landforms can you get and how are they formed? 1 2 34 5 67 8 10 11 9

28 Features created by Erosion Caves, Arches, Stacks and Stumps.... Headland The Sea A crack appears from a weakness in the headland The sea, through hydraulic action and corrasion erodes the crack into a cave The sea, continues to erode the cave until the caves reaches the other side of the headland causing an arch Stump The top of the arch is eroded by weathering. Both from plants and the weather. The top falls in and results in a stack. The top of the stack is eroded from weathering and the bottom from waves.. The top falls off resulting in a stump Stack

29 What depositional landforms can you get and how are they formed?

30 Explain the formation of a spit. (4 marks)

31 Case Studies: Coasts: 1.Impacts of Rising Sea level = The Maldives 2.Recent Cliff Collapse = Holderness Coastline 3.Coastal Management (Costs/Benefits) = Holderness Coastline 4.Coastal Habitat with distinct Characteristics = Keyhaven Salt Marsh, Hampshire

32 The Maldives 300 000 people 1190 islands, 80% of the land is 1m below sea level! Sea levels are rising by 0.9cm a year. 1. The Impacts of Rising Sea Level THE MALDIVES

33 What is Global Warming? What are the affects on coastlines?

34 What are the figures? 2mm a year increase in sea level (20cm over last century!) Predicted 18-60cm rise in the next century! What is causing the rise? Ice cap and Glacier melt PLUS thermal expansion

35 Collapse of the West Antarctic ice sheet and Greenland could cause a 6 metre rise and could happen within a 100 years!!!! This image is a computer generated simulation of what could happen in the future to the UK…………………..

36 The IMPACTS of rising sea level 1. Loss of Tourism 4. Buying land in other countries 2. Loss of beaches 3. Loss of Coral Reefs 6. Houses destroyed 7. Loss of Soil 5. Disrupted fishing industry 8.Asking for aid Which are: Economic

37 The IMPACTS of rising sea level 1. Loss of Tourism 4. Buying land in other countries 2. Loss of beaches 3. Loss of Coral Reefs 6. Houses destroyed 7. Loss of Soil 5. Disrupted fishing industry 8.Asking for aid Which are: Economic

38 The IMPACTS of rising sea level 1. Loss of Tourism 4. Buying land in other countries 2. Loss of beaches 3. Loss of Coral Reefs 6. Houses destroyed 7. Loss of Soil 5. Disrupted fishing industry 8.Asking for aid Which are: Environmental?

39 The IMPACTS of rising sea level 1. Loss of Tourism 4. Buying land in other countries 2. Loss of beaches 3. Loss of Coral Reefs 6. Houses destroyed 7. Loss of Soil 5. Disrupted fishing industry 8.Asking for aid Which are: Environmental?

40 The IMPACTS of rising sea level 1. Loss of Tourism 4. Buying land in other countries 2. Loss of beaches 3. Loss of Coral Reefs 6. Houses destroyed 7. Loss of Soil 5. Disrupted fishing industry 8.Asking for aid Which are: Social?

41 The IMPACTS of rising sea level 1. Loss of Tourism 4. Buying land in other countries 2. Loss of beaches 3. Loss of Coral Reefs 6. Houses destroyed 7. Loss of Soil 5. Disrupted fishing industry 8.Asking for aid Which are: Social?

42 Case Studies: Coasts: 1.Impacts of Rising Sea level = The Maldives 2.Recent Cliff Collapse = Holderness Coastline 3.Coastal Management (Costs/Benefits) = Holderness Coastline 4.Coastal Habitat with distinct Characteristics = Keyhaven Salt Marsh, Hampshire

43 Guess The Coastal Management LO1: To know what management strategies there are

44 Guess The Coastal Management LO1: To know what management strategies there are

45

46 Hard or Soft? 1.Match up the defence with their names 2.Are they are Hard or Soft forms of engineering A 6. Managed Retreat 4. Gabion B C D E F G 1. Sea wall 3. Beach Nourishment 8. Revetment 5. Rip Rap 7. Breakwater H 2. Groyne

47 Which form of coastal management is the most sustainable? Think about Economically (Money), Environmentally (Natural Environment) and Socially (People) Sea Wall Cost: £3,500-5,000 per Metre Lifespan: 100 years Beach Replenishment Cost: £5,000-200,000 per 100m Lifespan: 1-10 years. Gabions Cost: £1,000 perM3 Lifespan: 10 Years Wooden Groynes Cost: £1,000 per M Lifespan: 30-40 Years

48

49 2&3. The Holderness Coastline: Cliff Collapse and Coastal Management A case study to show an area of cliff collapse- rates of erosion, reasons why some areas are susceptible, how people may make the situation worse, impacts on people’s lives and the environment 2m lost a year!!!

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51 Unstable cliffs can often collapse if they are undercut by wave action, weathering, or are susceptible to mass movement

52 As a result of the landslide the edge of the cliff recedes.

53 2&3. The Holderness Coastline: Cliff Collapse and Coastal Management The costs and benefits of coastal management Mappleton: 50 Properties 2m a year lost Access road only 50m from the coast now! Geology: Areas rock is Till (Very soft!) Management: 1991  £2million on 2 x Rock Groynes and a rock revetment  These created a beach, reducing erosion. HOWEVER…. Down coast erosion has INCREASED!! Even on a neap time (30% lower than a normal tide) the waves reach the cliffs and erode them!!

54 What else is causing the erosion apart from Geology?

55 Businesses lost or under threat. Farmland Eroded House Prices Reduced, Insurance companies wont pay out Homeowners wont get insurance OR it will be VERY expensive Loss of homes at Withernsea

56 Use a Case Study to describe the effects of coastal flooding (4 Marks) Explain why areas such as Lyme Regis use both hard and soft engineering strategies (8 Marks)

57 Case Studies: Coasts: 1.Impacts of Rising Sea level = The Maldives 2.Recent Cliff Collapse = Holderness Coastline 3.Coastal Management (Costs/Benefits) = Holderness Coastline 4.Coastal Habitat with distinct Characteristics = Keyhaven Salt Marsh, Hampshire

58 4. Keyhaven Salt Marsh, Hampshire A coastal habitat with distinct characteristics How its been formed Its features What plants and animal species are there Ways to conserve sustainably whilst still using the area Hurst Castle Spit Keyhaven Salt Marsh

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60 Cordgrass Sea Lavender Wold Spider Oyster Catcher Ringed Plover How are these suited to life on the spit?

61 Conservation and Sustainable Use What pressures does the salt marsh face? – Sea Level rise and Climate change causing severe storms and flooding. (Loss of 6m a year) – Breaching of the spit (1989) How will it be conserved? – 1996 (£5 million) Rip Rap Installed and Beach Nourishment – Protected by SSSI status – acess and development limited

62 Use a Case Study to explain why a coastal habitat has distinct characteristics (8 Marks) Using a case study, discuss the effects of cliff collapse on peoples lives and the environment (8 Marks)


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