The Restless Earth

HideShow resource information
  • Created by: GBushell
  • Created on: 08-04-14 17:11
View mindmap
  • The Restless Earth
    • Unstable Earth
      • plate margins
        • CONSTRUCTIVE - where the plates are moving apart
          • magma rises from the mantle, cools and creates new crust
        • CONSERVATIVE - where the plates slide past each other
          • moving in either the same or opposite directions, no crust is created or destroyed
        • DESTRUCTIVE - where the plates collide
          • oceanic plate subducts below continental plate into the mantle creating volcanoes and ocean trenches
      • types of crust
        • OCEANIC CRUST - what you get under the oceans
        • CONTINENTAL CRUST - what you get nder the continents, or land masses
    • Landforms at Plate Margins
      • fold mountains - where crust is pushed upwards e.g. andes, alps, himalayas
      • ocean trenches - where crust is forced together and down e.g. mariana trench (deeper tan mt. everest's height)
      • Volcanoes
        • COMPOSITE Volcanoes - @ destructive plate margins, steep sides and alternate layers of ash and lava, sticky lava, doesn't flow far, acidic lava, violent eruptions, not frequent
        • SHIELD Volcanoes - @ constructive plate margins, wide base and gently sloping sides, runny lava, flows a long way, not violent eruptions, frequent
    • Supervolcanoes
      • the magma is blocked from eaching the Earth's surface
      • the pressure begins to build up, more rock melts and more magma is formed - creating a vast MAGMA CHAMBER
      • when the pressure becomes too much, the entire surface above the magma chamber is blown away by a huge explosion, forming and CALDERA
      • Impacts
        • magma would be flung 50km into the atmosphere
        • virtually all life up to 1000km would be killed by falling ash, lava flows and the force of the explosion
        • 1000km³ of lava would pour out of the volcano - enough to cover the whole of the USA with a layer 12.5cm thick
    • Scales to Measure earthquakes
      • MERCALLI - measures the effects of an eruption on land, people and buildings
        • 1 = rarely ever felt by people       12 = ruinous, catastrophic event
      • RICHTER - scale goes up increments as follows - 1, 10, 100, 1000 and so on instead of 1,2,3,4...An earthquake measured at 7 on the Richter scale therefore is 10 times stronger than 6, and 100 times stronger than one measured at 5.
    • Case Study
      • ANdes
      • Montserrat
      • Yellowstone
      • Haiti and Chile earthquakes
      • Boxing Day tsunami


No comments have yet been made

Similar Geography resources:

See all Geography resources »See all The Restless Earth resources »