Leaving Certificate Geography

  • Home
  • Physical Geography
    • Skills (Maps, Photos, Graphs) >
      • Ordnance Survey Map skills
      • Aerial photographs
      • Graph skills
    • Horizons Second Edition >
      • Chapter 1 Plate Tectonics
      • Chapter 2 Folding and Faulting
      • Chapter 3 Earthquakes
      • Chapter 4 Volcanoes
      • Chapter 5 The rock cycle
      • Chapter 6 Weathering
      • Chapter 7 The Karst Landscape
      • Chapter 8 Mass Movement
      • Chapter 9 Rivers
      • Chapter 10 Coastal Studies
    • Planet and People physical chapters >
      • Plate tectonics >
        • Plate Tectonics 2
        • Plate Tectonics 3
      • Rock Formation and Cycle >
        • Rocks
        • Rock types and their formation
        • Rock Cycle
        • Rock Cycle 2
        • The Rock Cycle 3
        • Rock Landscapes: Limestone
        • Intrusive and Extrusive volcanic landforms
        • Human interaction with the rock cycle
        • Tara Mines case study
      • Folding and Faulting
      • Weathering and Erosion
      • River processes and features
      • Glaciation
      • Coastal Studies >
        • Coastal Studies Ms. Carr
  • Regional Geography
    • Horizons Regional Chapters >
      • Chapter 22 Concept of a region
      • Chapter 23 The Western Region
      • Chapter 24 The Greater Dublin Area
      • Chapter 25 The Paris Basin
      • Mezzogiorno: Peripheral European region
      • Subcontinental India
    • Planet and People Regional Chapters >
      • Regional Geography Outline
      • Definition of Regions
      • Ireland: The Greater Dublin Region - Core
      • West of Ireland - Ms. Carr
      • The West of Ireland : Peripheral Region
      • Core region: Paris Basin
      • European Regions (Core Periphery) >
        • Paris Basin: Ms. Carr
        • Mezzogiorno - peripheral region
        • Mezzogiorno: European Peripheral Region
      • Subcontinental Region: India >
        • Introduction
        • India: Powerpoint
        • India: Secondary Activities
        • India: Tertiary Activities
        • India: Ms. Carr
      • EU enlargement
  • Elective: Human Environment
    • Folens: Human Elective >
      • Chapter One: Populations
      • Chapter 2 Human development and overpopulation
      • Chapter 3 The dynamics of settlement
      • Chapter 4 Migration
      • Chapter 5 Urban problems
      • Chapter 6 Urban settlement and planning issues
    • Planet and People: Human Elective >
      • Chapter 1: Population Studies >
        • Population test
      • Chapter 2 Overpopulation in Sudan >
        • Overpopulation question
        • Overpopulation and Resources
      • Chapter 3: Migration >
        • Migration Test
        • Student presentations
        • Student Presentations 2
      • Chapter 4 Settlement >
        • Settlement Patterns
        • Student work
        • Student work 2
      • Urban Sprawl-Introduction
      • Chaper 5 Three urban land use models >
        • Chapter 5: Land use change
      • Chapter 6 Urban problems in developed world cities
      • Chapter 7 Heritage Issues & Environmental Issues
      • Chapter 8 Urban planning strategies in Ireland >
        • Chapter 9 Developing world cities / counter-urbanisation
  • Culture and Identity (Hons)
    • Physical indicators of population
    • Cultural indicators of population
    • Nationality and Nation states
    • Case study: Switzerland
  • Geoecology (Hons)
    • Soils
    • Aridisoils
    • Brown earth soils
    • Latosols - Tropical rainforest soil
    • Soil Formation
    • Soil erosion - human activities
    • Soil erosion - preventative methods
    • Biome: Tropical rainforest
  • Field Investigation
    • 2013 field study
  • Exam and Papers
    • Leaving Cert Exam
    • Honours Paper
    • Ordinary Paper
    • What do I study?
  • Revision Centre
    • Physical Revision >
      • Physical Powerpoints
      • Plate tectonic questions
      • Volcano & Earthquake questions
      • Rock revision
      • River Revision
      • Glaciation Revision
    • Regional Revision >
      • Regional Powerpoints
      • EU expansion revision
      • European Regional Revision
    • Elective Revision >
      • Human Elective Powerpoints
      • Economic short questions (H&O)
    • Geoecology Option >
      • Geoecology Powerpoints
      • Geoecology questions
    • Sample Answers >
      • Sample Answers Outline
      • Physical: Sample Answers >
        • Waterfall: River Landform
        • Delta: River Landform
        • Cirques: Glacial landform
        • Drumlin: Glacial landform
        • Cave,Arch,Stack,Stump: Coastal landform
        • Beaches: Coastal landform
        • Isostatic and Eustatic Processes
        • Human control of natural processes
        • Impact of Flood Control
        • Impact of Coastal Management
        • Landform in a Karst landscape
        • Weathering and Erosion
      • Regional: Sample Answers >
        • Regions are areas defined by one or more criteria (two discussed)
        • Agriculture in Irish region influenced by factors
        • Development of agriculture in Mezzo influenced by factors
        • Development of agriculture in Paris Basin influenced by factors
        • Development of secondary activities in a Core Region
        • Industry in The Greater Dublin Area
        • The Gaeltacht
        • Climatic Region: The Cool Temperate Oceanic Climate
        • Tertiary activities in the Paris Basin
        • Two EU policies and their impact
        • EU expansion and the impact on a member state
        • The defining role of Culture (India)
        • Urban Growth : Kolkata, India
        • Growth of an urban area Paris
        • Culture defining a region - India -outline
      • Elective: Sample Answers >
        • Migration
        • Overpopulation
        • Three Urban Models
        • Geoecology: Sample Essays >
          • Soil Formation
          • Characteristics of soil
          • How human activities can accelerate soil erosion
          • Natural processes and soil
          • Tropical rainforest biome
          • Human interaction with a biome
        • Urban problems and solutions
        • Map work: Location of a Town
      • Swapped powerpoints
  • General Information
    • Geography at Leaving Cert level
  • Home
  • Physical Geography
    • Skills (Maps, Photos, Graphs) >
      • Ordnance Survey Map skills
      • Aerial photographs
      • Graph skills
    • Horizons Second Edition >
      • Chapter 1 Plate Tectonics
      • Chapter 2 Folding and Faulting
      • Chapter 3 Earthquakes
      • Chapter 4 Volcanoes
      • Chapter 5 The rock cycle
      • Chapter 6 Weathering
      • Chapter 7 The Karst Landscape
      • Chapter 8 Mass Movement
      • Chapter 9 Rivers
      • Chapter 10 Coastal Studies
    • Planet and People physical chapters >
      • Plate tectonics >
        • Plate Tectonics 2
        • Plate Tectonics 3
      • Rock Formation and Cycle >
        • Rocks
        • Rock types and their formation
        • Rock Cycle
        • Rock Cycle 2
        • The Rock Cycle 3
        • Rock Landscapes: Limestone
        • Intrusive and Extrusive volcanic landforms
        • Human interaction with the rock cycle
        • Tara Mines case study
      • Folding and Faulting
      • Weathering and Erosion
      • River processes and features
      • Glaciation
      • Coastal Studies >
        • Coastal Studies Ms. Carr
  • Regional Geography
    • Horizons Regional Chapters >
      • Chapter 22 Concept of a region
      • Chapter 23 The Western Region
      • Chapter 24 The Greater Dublin Area
      • Chapter 25 The Paris Basin
      • Mezzogiorno: Peripheral European region
      • Subcontinental India
    • Planet and People Regional Chapters >
      • Regional Geography Outline
      • Definition of Regions
      • Ireland: The Greater Dublin Region - Core
      • West of Ireland - Ms. Carr
      • The West of Ireland : Peripheral Region
      • Core region: Paris Basin
      • European Regions (Core Periphery) >
        • Paris Basin: Ms. Carr
        • Mezzogiorno - peripheral region
        • Mezzogiorno: European Peripheral Region
      • Subcontinental Region: India >
        • Introduction
        • India: Powerpoint
        • India: Secondary Activities
        • India: Tertiary Activities
        • India: Ms. Carr
      • EU enlargement
  • Elective: Human Environment
    • Folens: Human Elective >
      • Chapter One: Populations
      • Chapter 2 Human development and overpopulation
      • Chapter 3 The dynamics of settlement
      • Chapter 4 Migration
      • Chapter 5 Urban problems
      • Chapter 6 Urban settlement and planning issues
    • Planet and People: Human Elective >
      • Chapter 1: Population Studies >
        • Population test
      • Chapter 2 Overpopulation in Sudan >
        • Overpopulation question
        • Overpopulation and Resources
      • Chapter 3: Migration >
        • Migration Test
        • Student presentations
        • Student Presentations 2
      • Chapter 4 Settlement >
        • Settlement Patterns
        • Student work
        • Student work 2
      • Urban Sprawl-Introduction
      • Chaper 5 Three urban land use models >
        • Chapter 5: Land use change
      • Chapter 6 Urban problems in developed world cities
      • Chapter 7 Heritage Issues & Environmental Issues
      • Chapter 8 Urban planning strategies in Ireland >
        • Chapter 9 Developing world cities / counter-urbanisation
  • Culture and Identity (Hons)
    • Physical indicators of population
    • Cultural indicators of population
    • Nationality and Nation states
    • Case study: Switzerland
  • Geoecology (Hons)
    • Soils
    • Aridisoils
    • Brown earth soils
    • Latosols - Tropical rainforest soil
    • Soil Formation
    • Soil erosion - human activities
    • Soil erosion - preventative methods
    • Biome: Tropical rainforest
  • Field Investigation
    • 2013 field study
  • Exam and Papers
    • Leaving Cert Exam
    • Honours Paper
    • Ordinary Paper
    • What do I study?
  • Revision Centre
    • Physical Revision >
      • Physical Powerpoints
      • Plate tectonic questions
      • Volcano & Earthquake questions
      • Rock revision
      • River Revision
      • Glaciation Revision
    • Regional Revision >
      • Regional Powerpoints
      • EU expansion revision
      • European Regional Revision
    • Elective Revision >
      • Human Elective Powerpoints
      • Economic short questions (H&O)
    • Geoecology Option >
      • Geoecology Powerpoints
      • Geoecology questions
    • Sample Answers >
      • Sample Answers Outline
      • Physical: Sample Answers >
        • Waterfall: River Landform
        • Delta: River Landform
        • Cirques: Glacial landform
        • Drumlin: Glacial landform
        • Cave,Arch,Stack,Stump: Coastal landform
        • Beaches: Coastal landform
        • Isostatic and Eustatic Processes
        • Human control of natural processes
        • Impact of Flood Control
        • Impact of Coastal Management
        • Landform in a Karst landscape
        • Weathering and Erosion
      • Regional: Sample Answers >
        • Regions are areas defined by one or more criteria (two discussed)
        • Agriculture in Irish region influenced by factors
        • Development of agriculture in Mezzo influenced by factors
        • Development of agriculture in Paris Basin influenced by factors
        • Development of secondary activities in a Core Region
        • Industry in The Greater Dublin Area
        • The Gaeltacht
        • Climatic Region: The Cool Temperate Oceanic Climate
        • Tertiary activities in the Paris Basin
        • Two EU policies and their impact
        • EU expansion and the impact on a member state
        • The defining role of Culture (India)
        • Urban Growth : Kolkata, India
        • Growth of an urban area Paris
        • Culture defining a region - India -outline
      • Elective: Sample Answers >
        • Migration
        • Overpopulation
        • Three Urban Models
        • Geoecology: Sample Essays >
          • Soil Formation
          • Characteristics of soil
          • How human activities can accelerate soil erosion
          • Natural processes and soil
          • Tropical rainforest biome
          • Human interaction with a biome
        • Urban problems and solutions
        • Map work: Location of a Town
      • Swapped powerpoints
  • General Information
    • Geography at Leaving Cert level

Coastal Studies

What are high energy coasts?
  • stretches of the coastline where waves are powerful for a
    significant part of the year

  • often the rate of erosion exceeds the rate of deposition

  • landforms include headlands, cliffs and wave-cut platform
Waves
Waves are created by the action of wind blowing over the surface of the sea.
Wave energy depends on 
  • wind strength
  • wind duration (how long the wind is blowing)
  • water depth
  • the fetch of the wave

Fetch is the maximum distance of open sea a wave can travel over.

The highest part of a wave is the crest and the lowest point is the trough.
The difference between crest and trough is the wave height.

Out at sea, water moves in a circular motion as each wave passes. The water
does not move across the ocean. Only the energy of the wave moves.  But when a
wave approaches land, friction with the sea bed makes the base of the wave
travel more slowly than the top of the wave. The top of the wave will eventually
topple over, and the wave will break.

When a wave breaks, water washes forward onto the sea-shore. This part of the
wave is called the swash. The swash transfers energy up the beach. The water
that returns down the beach is called the backwash. The backwash returns energy
down the beach.

Constructive waves and destructive waves
There are two types of wave: constructive waves and destructive waves.
  • Constructive waves have limited energy. Most of this is used by the backwash
    to transport material up the beach. Constructive waves are lower and less
    frequent (under 13 waves per minute). They have a strong swash that pushes
    material up the beach.

  • Destructive waves have much more energy. Most of this is used by the
    backwash to transport material back down the beach. Destructive waves are higher
    and more frequent (about 15 waves per minute). They have a strong backwash that
    scours the beach and pulls material down the beach.

Beach angle affects the strength of the backwash. If the beach is gentle,
little water percolates into the sand. Instead it will wash down the beach and
destroy the swash from the next wave. If the beach is steep, more water
percolates into the sand and so the backwash is weak.

Wave refraction
The direction in which a wave moves may be altered by the shape of the
coastline. Waves travel faster in deeper water. If, for example, a wave is
approaching a coast at an angle, it will bend round, as the side of the wave
nearer to the coast travels more slowly. This is because the side nearer the
coast loses more energy to friction, as the sea is shallower. The shape of the
waves is also affected by headlands and bays.

Wave refraction where waves are diagonal to the coast
Wave refraction in an indented coastline
Waves can be refracted if they pass through a narrow channel

Coastal erosion
The processes of erosion, transport and deposition at the coast are similar
to the processes in fluvial environments. There are five types of coastal
erosion. 
  • Hydraulic action - air present in joints is trapped and compressed by the
    pressure of incoming sea-water. Over a period of time, this increase in pressure
    weakens and breaks off the rock. The rate of hydraulic action is high on coasts
    where waves are powerful and the coastline is made up of a densely jointed
    rock.

  • Corrasion (abrasion) - sand, shingle and boulders, carried by the sea, rub
    against the surface of cliffs and wear it down. It is the fastest form of
    coastal erosion

  • Attrition - the movement of waves makes rocks and pebbles crash together, so
    that sharp edges are broken down, and particles become smaller and more rounded.
    It affects boulders and stones that have already been eroded from the coast.

  • Corrosion (solution) - occurs when rocks are dissolved by sea water.

  • Biological action - boring organisms (e.g. limpets) can drill into the rock
    and create small depressions. Seaweed attaches itself to rocks and the action of
    the waves can be enough to cause the swaying seaweed to prise away loose
    material from the sea bed.

Factors affecting the rate of coastal erosion
The rate of erosion is affected by the force of the waves (erosivity) and the resistance of the coast to erosion (erodibility).

What determines the force of the waves?

  • Breaking point of the wave - when a wave breaks it releases a great deal of
    energy. A wave which breaks at the foot of a cliff releases the most energy and
    causes fastest erosion, particularly corrasion. A wave which breaks offshore
    will have lost most of its energy as it travels up a beach.

  • Type of wave - steep destructive waves have more energy, and power to erode,
    than shallow constructive waves.

  • Fetch of the wave - waves tend to become higher and more erosive as their
    fetch increases.

  • Shape of coastline - refraction makes waves stronger and more erosive on
    headlands rather than bays.

  • Gradient of the sea-bed - the steeper the gradient of sea-bed, the more
    likely it is that the wave will break closer to the shore. Less of the wave's
    energy is used in overcoming friction with the sea-bed, so there is more energy
    to erode.

What determines the resistance of the coast to erosion?

  • Mechanical strength of rocks - some rocks (e.g. granite) are stronger and
    more resistant to erosion than others (e.g. unconsolidated sediments such as
    volcanic ash). Rocks which can become saturated with water can collapse (e.g.
    fuller's earth).

  • Jointing - densely jointed or faulted rocks are susceptible to hydraulic
    action. Faults, joints, cracks and bedding planes can all act as points of
    weakness.

  • Chemical composition of rock - some rocks are soluble in water (e.g. chalk
    is soluble in acidified water) and can be eroded by corrosion.

  • Vegetation - the foliage and roots of vegetation bind soil and rocks
    together and reduce the rate of erosion.

  • Human protection - in many locations, physical structures (e.g. sea walls)
    have been installed to absorb the energy of waves and so reduce the rate of
    erosion
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