EQ 1 - Coasts

What are they:

• Small ridges or hills of sand covered in vegetation found at the top of a beach, above the usual maximum reach of the waves. 

Formed: 

• Sand and winds that blow the sand inland. Plants colonise the dunes which stabilise them. 

Example of plants: 

• Prickly Saltwort 
• Marron Grass
• Sand Sedge 

Location example:

• Ainsedale, Formby
• Mersyside

What are they:

• Areas of flat silty sediments with numerous channels running through

How are they formed:

• Shaltered areas with low energy where deposition occurs, where there are no strong tides or currents to carry away sediment 

Examples of plants:

• Glasswort 
• Marshgrass
• Cord grass

Location examples:

• Norfolk coast
• Eden Esturary of Fife 
• Surn Head

• Supply of sediment 

• Low energy environment 

• Initial deposition 
  • detntus line sand dunes 
  • mudflats salt marshes 
• Pioneer species colonise 
  • sediment trap
  • bind sediment 
  • add nutrients 
• Landforms develop
  • mudflats height increase (salt marsh)
  • mobile dunes develop (dunes) 

Surrounding area:

• Prevents flooding / erosion
• Can be built on once stable 
• Tourism 
• Helps maintain a wide beach

Brings stability:

• Sediment trap 
• Stabilises - binds sediment 
• Adds nutrients 
• Retains water 
• Stops flooding 
• Stops erosion 

Rock types:

• Chalk
• Welden Clay
• Portland + Purbeck Limestone 

Discordent:

• Perpendicular to coastline

Concordent:

• Parallel to coastline

Inputs:

• Supply from land 
  • Coast erosion 
  • Beach nourishment 
  • Sand supply from rivers
• Reversible processes 
  • Wind transportation 
  • Releasing / trapping of land 
• Decrease supply from land 
  • Trapping sand at structures 
  • Coast protection 
  • Beach sand mining 

Outputs:

• Offshore supply
  • Onshore transport 
  • Shore face nourishment 
• Reversible processes 
  • Calcium carbonate production and loss
• Offshore loss 
  • Nearshore submarine canyon
  • Dredging 
  • Offshore transport during storm and tidal wave conditions 
  • Offshore loss due to sea level rise

• Sea
  • Backshore 
  • Foreshore 
  • Nearshore 
  • Off-shore 
• Land

Short term:

• Climate 
• Storm surges 
• Waves 
• Tides 
• Wind 
• Weather 

Long term:

• Climate change 
• Tectonic activity 
• Ocean currents 
• Rock type
• Human activity 

Inputs:

• Waves 
• Tides 
• Storm surges 
• Ocean currents 
• Wind
• Weather 
• Climate 
• Climate change 
• Rock type
• Vegitation 
• Tectonic activity 
• Human activity 
• Coastal management 

Processes :

• Hydraulic action  
• Abrasion 
• Corrosion 
• Attrition 
• Saltation 
• Traction
• Suspension 
• Long-shore drift
• Freeze-thaw 
• Chemical
• Biological
• Accumulation 
• Flocculation 
• Slides 
• Creep 
• Slump 

Outputs: 

• Cracks 
• Caves 
• Arches 
• Stacks 
• Stumps 
• Blowholes
• Wave-cut platforms
• Sand dunes 
• Beaches 
• Tombolos
• Spits 
• Bars 
• Dalmation coasts 
• Haff coastlines 
• Slides
• Creep 
• Slump 

• Waves
  • Calmer conditions 
  • Short fetch 
  • Less powerful waves (constructive)
  • Sheltered from largest waves 
• Processes 
  • Deposition and transport 
  • Sediment from river, longshore drift and nearshore currents 
• Landforms 
  • Beaches, spits, salt, marshes, sand dunes, bars, mudflats
• General location 
  • Coastal plain landscape
  • Lowland landscape 
• Example locations 
  • East Anglian 
  • Mediterranean 

• Waves 
  • Long fetch 
  • Most powerful waves (constuctive)
  • Exposed to largest waves
  • Storm condidtions
• Processes
  • Erosion and transportation 
  • Sediments from eroded land, mass movement and weathering, off-shore currents
• Landforms 
  • Cliffs, wave-cut platforms, arches, sea, caves, stacks
• General location 
  • High land and lowland coastline 
  • Rocky landscape
• Example locations
  • Atlantic coasts of Norway and Scotland  

1. Rocks dipping towards coastline wunerable to mass movement 

    Soft clay erodes more quickly chalk is unsupported 

    Joints make the cliff face more unstable 

2. Coal seam erodes more quickly then sandstone creates hang

    Glacial boulder clay unconsilidated so slides off the cliff 

3. Vunerable to erosion in weaknesses, can hold its form holding arches 

4. Not vunerable to erosion 

    No joints/ bedding planes 

    Steep cliff

5. Creates mass movement along bedding planes 

Igenous: 

• Formed when magma is cooled 
• E.g. Granite/ Magma 

Sedimentary:

• Formed by small particles, forming layers in the the water, compressed 
• E.g. Granite/ Basalt 

Metamorphic:

• Formed by heat and pressure changing the rocks
• E.g. Slate (clay)/ Limestone (marble)