Physical Geography

The Earth's Crust
1. Plates
  1. Oceanic Plate
    1. made of Basalt
    2. are between 5Km and 10Km thick
    3. 'Floats on a very hot mantle
  2. Continental Plate
    1. made of Granite
    2. between 25Km and 90Km thick
    3. 'floats' on a very hot mantle
2. Plate Margins
  1. Destructive
    1. Oceanic and Continental plates are pushed together
    2. Earthquakes occur here due to fault line
    3. Fold Mountains are made
  2. Constructive
    1. Oceanic or Continental plates pull apart
    2. Creates Volcanoes
  3. Conservative
    1. Plates are pushed in different directions
    2. Earthquakes occur here due to a fault line made
3. Restless Earth
  1. Fold Mountains
    1. formed on destructive plate margins
    2. Geosyncline
      1. A very large downfold in the Earth's crust which fills up over time with sediment
    3. the rocks in the crust are compressed and folded into ANTICLINES (upfolds) and SYNCLINES (downfolds)
  2. Volcanoes
    1. Types of volcanoes
      1. Shield Volcanoes
        Found on Constructive plate margins
        Basic Lava (1200C)
        runny and flows long distances before cooling and soldifying
        many eruptions form a coneshaped mountain with gently sloped sides
        E.G Mauna Loa, Hawaii, USA
      2. Composite Volcanoes
        Acid Lava (800C)
        thick and sticky
        alternate eruptions cause ash followed by lava to build up a cone shape with steep sides
        Found on Destructive plate margins
        E.G Mt St Helens, Washington, USA
      3. Supervolcanoes
        found on Destructive plate margins
        Massive explosions of ash form a sunken crater
        ash would fall across the whole Earth killing everything
        Yellowstone Caldera, Wyoming, USA
  3. Earthquakes
    1. The Cause
      1. Plates are locked together via friction and pressure builds up over many years
      2. the Crustal rock breaks suddenly underground causing a focus point in the rock
      3. stored energy is released in seconds and travels outwards from the epicentre as shock waves
    2. recorded in SEISOMETER
    3. RICHTER SCALE measures the energy released
    4. MERCALLI SCALE measures the damage done
Coasts
1. Waves
  1. Destructive Waves
    1. remove beach material
    2. form in strong winds
    3. BACKWASH is STRONGER than SWASH
    4. a frequency of 11-15per minute
  2. Constructive Waves
    1. deposit beach material
    2. form in light winds with calm conditions
    3. SWASH is STRONGER than BACKWASH
    4. frequency of 6-9per minute
2. Erosion
  1. Hydraulic Power
    1. force of the waves crashing in the cliff
    2. air trapped in the cliff is compressed and fractures the rock
  2. Solution
    1. Rocks containing calcium carbonate slowly dissolve because of acidic water.
  3. Attrition
    1. pebbles are rolled backwards and forwards by waves
    2. as they rub against each other they're slowly worn away
  4. Abrasion
    1. Sand and pebbles are thrown against cliffs by breaking waves and wear them away
3. Transportation and Deposition
  1. Traction
    1. boulders and cobbles are rolled along by powerful waves
  2. Saltation
    1. pebbles and sand are bounced around
  3. Suspension
    1. silt and clay are suspended in moving sea water
  4. Solution
    1. minerals are dissolved in sea water
  5. Longshore Drift is the movement of material along a beach
4. Mass movement and Weathering
  1. Sliding
    1. Blocks of rock or loose material slide rapidly down the slope
  2. Slumping
    1. a mass of soil or clay slides downwards a curve slip-pane,
    2. forms a scar on the upslope and a toe on the downslope
5. Landforms
  1. Headlands and Bays
    1. a headland is an area of land that sticks out into the sea
    2. a bay is a curved coastal inlet
6. Hard engineering
  1. building structures or machinery to control the natural processes
  2. Sea walls
    1. concrete walls designed to reflect the wave energy
  3. Groynes
    1. wooden built barriers built across the beach to trap the sand and pebbles transported via longshore drift
  4. Rock armour
    1. large boulders or resistant rock placed at the base of the cliff to prevent erosion
7. Soft engineering
  1. working with the environment to modify or prepare for natural processes
  2. Beach nourishment
    1. beach material lost throughout longshore drift is replaced with material from further along the coast
  3. Dune regenration
    1. sand dunes are damaged by walkers or picnicker. areas of sand dynes are fenced off to allow them to re-grow naturally
  4. Marsh Creation
    1. areas of low economic value allow the sea to erode and flood the land.
      1. this then develops mud flats, salt marshes, and beaches.
Living world
1. Weather and Climate
  1. Depressions
    1. areas of low pressure formed when air masses of different temperatures meet.
  2. Anticyclones
    1. areas of high pressure formed when an air mass is slowly sinking
2. Ecosystems
  1. Nutrient Cycles
    1. all living things need nutrients to live and grow.
    2. the nutrients move through the ecosystem in a cycle
  2. Energy Flows
    1. plants and animals need energy to survive.
    2. energy flows through an ecosystem along the food chain

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Physical Geography

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