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.
1. + Elective Geog (New) Secondary 3N Week 6: Living with Tectonic Hazards
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. + Worksheet 1 Review: Understanding Command Words Describe Give a written factual account of the distinctive features of an item Describe the differences Compare
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 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 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 Important Note! Plates are NOT continents Plates include both continental and oceanic crust.
8. + Elective Geog (New) Secondary 3N Week 6: Living with Tectonic Hazards
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 Types of Plate Boundaries
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 Note areas with earthquakes & volcanic activities
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 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.
16. + 16 Oceanic-oceanic
18. + 18 Continental-continental
19. + Diverging: Continental- Continental African Plate African Plate (Nubian) (Somalian) East African Block Rift Valley BlockMountain Mountain
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