Elective Geography Secondary 3 Normal Academic (New)- Plate Tectonics 3


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  • Explain to students the difference between a fold mountain and a block mountain.Block mountains are formed by the downward movement of masses of land along lines of weakness while fold mountains are formed from the sideways motion of land being compressed.
  • Elective Geography Secondary 3 Normal Academic (New)- Plate Tectonics 3

    1. 1. + Elective Geog (New) Secondary 3N Week 6: Living with Tectonic Hazards
    2. 2. + 2 Worksheet 1: Review  Question 1  It is not a natural hazard as it is 6000km away  And a naturally occurring event is only a hazard when lives are affected and when properties are destroyed.  Question 2  Convection currents are movements of heat within the mantle  Material in the mantle is heated by the core, causing the mantle material to expand, rise and spread out beneath the plates  This causes plates to be dragged along and to move away from each other  Then the hot mantle material cools slightly and sinks, pulling the plate along
    3. 3. + Worksheet 1 Review: Understanding Command Words  Describe  Give a written factual account of the distinctive features of an item  Describe the differences  Compare
    4. 4. + Worksheet 1 Review: Understanding Command Words  Compare  Provide a point by point account of the similarities and differences between two sets of information or two areas  Must use comparative adjectives (eg. Larger than, smaller than, more steep than)  Two sets of descriptions does not make a comparison  May be written as “Describe/ List/ Identify the main differences/ similarities”
    5. 5. + 5 Worksheet 1 Review:  Question 3  Oceanic crust is found beneath deep oceans while continental crust is found beneath earth’s continental masses and under shallow seas close to continents  Oceanic crust has a thickness of between 5 and 8km which is thinner than the continental crust which has a thickness of between 30 and 60km  Oceanic crust is heavier and denser than the continental crust.  Oceanic crust consists mainly of basalt while a continental crust consists mainly of granite Use of comparatives
    6. 6. + 6 Worksheet 1 Review: Understanding Command Words  With a well annotated diagram  Add notes of explanation  Label with short comments a diagram to describe  Only the diagram and attached notes will be marked
    7. 7. + 7 Important Note!  Plates are NOT continents  Plates include both continental and oceanic crust.
    8. 8. + Elective Geog (New) Secondary 3N Week 6: Living with Tectonic Hazards
    9. 9. + 9 Lesson Outcomes  By the end of the lesson, we will be able to  describe the global distribution of tectonic plates and  types of plate boundaries.
    10. 10. + 10 Types of Plate Boundaries
    11. 11. + 11 Different types of plate boundaries  Divergent: where plates move away from each other  Convergent: where plates move towards each other  Transform: where plates move past each other
    12. 12. + 12 Note areas with earthquakes & volcanic activities
    13. 13. + 13 Divergent Plates  Areaswhere two plates move away from each other  Magma moves upward to the surface where it cools to form new oceanic crust along these boundaries  Oceanic-oceanic  Continental-continental
    14. 14. + 14 Oceanic-oceanic At various points along the ridge, magma The newly formed (youngest) rocks are builds up above the ocean to form volcanic closest to the middle of the ridge/plate islands. boundaries. Magma rises at the zone of New sea floor is formed when the magma divergence/spreading zone to form a ridge of Magma rises from the mantle to fill the gap cools and solidifies. This process is called new ocean floor called mid-oceanic ridge. between the plates as they diverge. sea-floor spreading.
    15. 15. 15
    16. 16. + 16 Oceanic-oceanic
    17. 17. 17
    18. 18. + 18 Continental-continental
    19. 19. + Diverging: Continental- Continental African Plate African Plate (Nubian) (Somalian) East African Block Rift Valley BlockMountain Mountain
    20. 20. + 20 Rift valleys and Block mountains  A fault  Fracture in the rocks along which the rocks are displaced  Due to tensional forces  Rift Valley  Is a valley with steep sides that is formed when the sections of the crust extend along fault lines  Block Mountain  A block of land with steep sides
    21. 21. + 22 Afar Triangle, Triple Divergent Triangle
    22. 22. 23armanalluwie.blogspot.com
    23. 23. 24http://www.youtube.com/watch?v=ic54PSuQwLE