Plate Movements Ppt

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This can be used in year 9 as well as year 10 - GCSE Syllabus

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Plate Movements Ppt

  1. 1. SPHERES OF THE EARTH <ul><li>The Earth has 4 spheres: </li></ul><ul><li>ATMOSPHERE </li></ul><ul><li>HYDROSPHERE </li></ul><ul><li>LITHOSPHERE </li></ul><ul><li>BIOSPHERE </li></ul>
  2. 2. EARTH’S INTERIOR <ul><li>The outer shell of the Earth is called the CRUST       </li></ul><ul><li>The next layer is called the MANTLE     </li></ul><ul><li>The next layer is the liquid OUTER CORE     </li></ul><ul><li>The middle bit is called the solid INNER CORE      </li></ul>
  3. 3. CONTINENTAL DRIFT THEORY
  4. 4. EARTH - PLATES
  5. 5. PLATES <ul><li>The Earth's surface is made up of a series of large plates (like pieces of a giant jigsaw puzzle). </li></ul><ul><li>These plates are in constant motion travelling at a few centimetres per year. </li></ul><ul><li>Plates 'float' on the molten rock magma. As the core of the Earth heats up the materials inside, the molten magma also gets heated up. The heat causes convection currents, a movement of rising and sinking caused by heat, inside the molten magma. </li></ul>
  6. 6. PLATE MARGINS <ul><li>The place where two plates meet is known as plate margin/ boundary. </li></ul><ul><li>There are 3 types of plate margins/ movements: </li></ul><ul><li>Diverging Plate Margin </li></ul><ul><li>Converging Plate Margin </li></ul><ul><li>Transform (Conservative) Plate Margin </li></ul>
  7. 7. DIVERGING PLATE MOVEMENTS <ul><li>Places where plates are coming apart are called divergent boundaries. </li></ul><ul><li>when Earth's brittle surface layer (the lithosphere) is pulled apart, it typically breaks along parallel faults that tilt slightly outward from each other. </li></ul><ul><li>Magma (liquid rock) seeps upward to fill the cracks. In this way, new crust is formed along the boundary. </li></ul><ul><li>Earthquakes occur along the faults, and volcanoes form where the magma reaches the surface. </li></ul><ul><li>For example, divergence along the Mid Atlantic ridge causes the Atlantic Ocean to widen at only about 2 centimeters per year. </li></ul>
  8. 8. CONVERGING PLATE MOVEMENTS <ul><li>When two plates move towards each other, they would collide. This is called a convergent plate movement. </li></ul><ul><li>As the plates collide, some crust is destroyed due to the impact, therefore this convergent boundary is also called a destructive boundary. </li></ul><ul><li>Examples: </li></ul><ul><li>the collision between the Eurasian Plate and the Indian Plate which is forming the Himalayas . </li></ul><ul><li>subduction of the Nazca Plate beneath the South American Plate to form the Andes Mountains . </li></ul>
  9. 9. WHEN TWO CONTINENTAL PLATES CONVERGE
  10. 10. WHEN AN OCEANIC & CONTINENTAL PLATES CONVERGE
  11. 11. WHEN TWO OCEANIC PLATES CONVERGE
  12. 12. CONSERVATIVE PLATE MOVEMENT <ul><li>A transform plate movement is one where two plates slide laterally past each other. </li></ul><ul><li>This movement is not smooth due to friction between the rocks of the two plates. </li></ul><ul><li>When there is sufficient buildup of pressure, rocks in the plates break and get jerked apart. This results in earthquakes. </li></ul>
  13. 13. HAZARDS ASSOCIATED WITH PLATES <ul><li>Most EARTHQUAKES and VOLCANIC ERUPTIONS occur in specific areas, such as along plate boundaries. </li></ul>
  14. 14. EARTHQUAKES
  15. 15. EARTHQUAKE ZONES OF THE WORLD
  16. 16. EFFECTS OF EARTHQUAKES <ul><li>Negative effects of earthquakes: </li></ul><ul><li>Tremendous loss of life. </li></ul><ul><li>Loss of property. </li></ul><ul><li>Collapse of transport – roads, railways, ports, bridges. </li></ul><ul><li>Fire, landslides, floods. </li></ul><ul><li>Blocked roads </li></ul><ul><li>Facilities disrupted – electricity, water, medical . </li></ul><ul><li>Tsunamis </li></ul>
  17. 17. VOLCANO <ul><li>A Volcano is an opening or rupture on the Earth’s Surface which allows magma, rocks, gases etc. to come out from below the surface. </li></ul><ul><li>Causes of Volcanic activity : </li></ul><ul><li>Diverging plates </li></ul><ul><li>Converging plates </li></ul><ul><li>Hot Spots </li></ul><ul><li>Faults </li></ul><ul><li>Important Terms : </li></ul><ul><li>Vent and Fumeroles </li></ul><ul><li>Crater </li></ul><ul><li>Pyroclastic material </li></ul><ul><li>Lava flow </li></ul><ul><li>Magma Chamber </li></ul><ul><li>Cone shaped hill </li></ul>
  18. 18. TYPES OF MATERIAL - VOLCANO <ul><li>Three types of materials are ejected out of a Volcano: </li></ul><ul><li>SOLIDS : ash particles (< 2mm in size); Lapilli (2 – 64mm in size); Volcanic bombs (>64 mm in size) </li></ul><ul><li>LIQUIDS : Molten material – Magma, Hot water from geysers and hot springs. </li></ul><ul><li>GASES : Water-vapour, carbon monoxide, carbon dioxide, sulphur dioxide, hydrogen chloride, hydrogen fluoride, </li></ul>
  19. 19. TYPES OF VOLCANOES <ul><li>On the basis of frequency : </li></ul><ul><li>Active Volcano: which erupt frequently & can erupt any time. Eg. Mt. Mauna Loa, Hawaii. </li></ul><ul><li>Dormant Volcano: which have erupted in history but have not erupted since then. Eg. Mt. Rainier, USA </li></ul><ul><li>Extinct Volcano: which may have erupted earlier but is now almost dead (>1000 yrs.) Eg. Mt. Kilimanjaro, Tanzania </li></ul><ul><li>On the basis of shape and material they are made of: </li></ul><ul><li>Shield Volcano: Gentle slopes, basaltic lava, low viscosity. Eg. Mt. Mauna Loa, Hawaii </li></ul><ul><li>Cinder Volcano: Steep slopes, > 300 meters in height, made of pyroclastic material. Eg. Mt. Paracutin, Mexico </li></ul><ul><li>Composite / Strato Volcano: Steep upper slopes & then gentle, Alternate layers of lava & ash. Eg. Mt. Vesuvius, Italy </li></ul>
  20. 20. TYPES OF ERUPTIONS <ul><li>There are five major types of eruptions: </li></ul><ul><li>Hawaiian </li></ul><ul><li>Strombolian </li></ul><ul><li>Vulcanian </li></ul><ul><li>Pelean </li></ul><ul><li>Plinian </li></ul>
  21. 21. TYPES OF ERUPTIONS
  22. 22. VOLCANIC ZONES OF THE WORLD
  23. 23. EFFECTS OF VOLCANO <ul><li>Positive Effects: </li></ul><ul><li>Ash add to the soil fertility – farming </li></ul><ul><li>New minerals may be discovered </li></ul><ul><li>Promotes Tourism </li></ul><ul><li>Research and education purposes. </li></ul><ul><li>Geothermal Energy – renewable energy. </li></ul><ul><li>Negative effects </li></ul><ul><li>Loss of life </li></ul><ul><li>Loss of property (economic loss) </li></ul><ul><li>Air Pollution (ash, smoke, gases, acid rain etc) </li></ul><ul><li>Water pollution </li></ul><ul><li>Lahars (mudflows with water) </li></ul><ul><li>Earthquakes </li></ul><ul><li>Increase in temperature of the area </li></ul>
  24. 24. ZONES OF EARTHQUAKES & VOCANOES

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