1. CL USB 6 Geography Yr 8 Place & Space 1 225 MILLION YEARS AGO

2. CL USB 6 Geography Yr 8 Place & Space 2 THE CONTINENTS TODAY

3. CL USB 6 Geography Yr. 8 Place & Space 3 Review of the Earth’s Surface Inner Core Outer Core Crust Mantle Convection Current Ridge Trench Cooled Rock Semi-molten Molten Metal Hot Solid Metal

4. CL USB 6 Geography Yr 8 Place & Space 4 Continental Drift Theory 1912 Alfred Wegener produced the theory of continental drift 200 million years ago 1 supercontinent Pangaea began splitting apart Into at least 15 large slab like plates ranging from 7 to about 200km thick Plates formed the continents we know today as ocean waters flooded into the spaces between the plates.

5. CL USB 6 Geography Yr 8 Place & Space 5 Eurasian Plate Pacific Plate Antarctic Plate Cocos Plate Nazca Plate North American Plate South American Plate African Plate Arabian Plate Indo Australian Plate Pacific Plate Philippine Plate

6. CL USB 6 Geography Yr 8 Place & Space 6 1.Upward movement of heat through the mantle. Hot magma in the Earth moves toward the surface, cools, then sinks again. 2.The effect that cooling has, as the energy is dissipated within the lithosphere. 3.This creates convection currents beneath the plates that cause the plates to move. Causes of Plate Movements

7. CL USB 6 Geography Yr 8 Place & Space 7

8. 8 Types of Plate Movements: Convergent – plates move toward one another Divergent – plates move away from each other Transform – plates move sideways past each other

9. CL USB 6 Geography Yr 8 Place & Space 9 Three types of plate boundary movement

10. CL USB 6 Geography Yr 8 Place & Space 10

11. CL USB 6 Geography Yr 8 Place & Space 11 Formation of the Himalayan Mountains

12. CL USB 6 Geography Yr 8 Place & Space 12 Summary Converging Plates Oceanic colliding with oceanic plate e.g. Mariana Trench 11km deep Pacific Ocean Continental Indo-Australian Plate colliding with Continental Eurasian Plate formed Himalayan Mts. World highest 100mts in Himalayas

13. CL USB 6 Geography Yr 8 Place & Space 13 Three types of plate boundary movement

14. CL USB 6 Geography Yr 8 Place & Space 14 Mid-oceanic ridge

15. CL USB 6 Geography Yr 8 Place & Space 15 Fissure Volcano

16. CL USB 6 Geography Yr 8 Place & Space 16 Example: Divergent Plate Movement The Mid-Atlantic Ridge 40 000 kms long Mid Atlantic Ridge formed between the North and South American plates and the Eurasian plate the ridge comes to the surface at Iceland

17. CL USB 6 Geography Yr 8 Place & Space 17 e.g. Mid-Atlantic Ridge

18. CL USB 6 Geography Yr 8 Place & Space 18

19. CL USB 6 Geography Yr 8 Place & Space 19 Three types of plate boundary movement

20. CL USB 6 Geography Yr 8 Place & Space 20 Transform Fault Boundaries Boundary between two plates that are sliding past each other (   ) EARTHQUAKES along faults

21. CL USB 6 Geography Yr 8 Place & Space 21 Example: Transform Plates Sliding plates violent earthquakes San Andreas Fault California Pacific Plate moving north, North American plate moving south

22. CL USB 6 Geography Yr 8 Place & Space 22 e.g. San Andreas Fault

23. CL USB 6 Geography Yr 8 Place & Space 23 e.g. San Andreas Fault  

24. CL USB 6 Geography Yr 8 Place & Space 24 Earthquake and Volcanic Activity The location of high levels of earthquakes and active volcanoes provide clear evidence of the edges (margins) of the tectonic plates What patterns do you notice in the next two maps?

25. CL USB 6 Geography Yr 8 Place & Space 25 Active Volcanoes What do you notice about their location?

26. CL USB 6 Geography Yr 8 Place & Space 26 Earthquakes What do you notice about their location?

27. CL USB 6 Geography Yr 8 Place & Space 27 Ring of Fire The most powerful earthquakes tend to be those surrounding the Pacific Ocean in the region known as the Ring of Fire. where plates such as the Pacific, Nazca and Philippines plates force their way under the surrounding continents More than 65% of the world’s volcanoes and 80% of the worlds earthquakes are located within the Ring of Fire

28. CL USB 6 Geography Yr 8 Place & Space 28 The Pacific “Ring of Fire”

29. CL USB 6 Geography Yr 8 Place & Space 29 Earthquakes The pressure / forces built up along the plate margins account for most of the world’s earthquakes When the stress created by these processes is released, a fault is produced within the crust and a series of vibrations or seismic waves spread out from the break point

30. CL USB 6 Geography Yr 8 Place & Space 30 Earthquakes Seismic waves travel up to 14 kms per second As they travel through rock they distort the rock and produce a rolling wavelike motion at the surface The point on the surface above the source is the epicentre

31. CL USB 6 Geography Yr 8 Place & Space 31 OFF THE WEST COAST OF NORTHERN SUMATRA: DECEMBER 26, 2004 MAGNITUDE 9.1 225,000+ people were killed or were presumed dead and About 1.7 million people were displaced by the earthquake and subsequent tsunami in 14 countries in South Asia and East Africa.

32. CL USB 6 Geography Yr 8 Place & Space 32 Tsunamis Where shock waves from an earthquake pass through the ocean they produce very fast moving waves called tsunamis World’s Major Earthquakes 1556 Shansi China 830 000 deaths 1976Tangsh China655 000 deaths 2004Indian Ocean225 000 deaths

33. CL USB 6 Geography Yr 8 Place & Space 33 Evidence to support the theory of Plate Tectonics Use of GPS Global Positioning Systems and Satellite Laser Ranging plot small movements in the continental plates 1964 Alaska earthquake measuring 9.2 on Richter scale over 8oo kms of coastline some areas pushed up 15 metres other ss subsided 2.5 metres

34. CL USB 6 Geography Yr 8 Place & Space 34 Advantages of Plate Movement Volcanic soils – fertile –produce lots of food Mineral deposits

35. CL USB 6 Geography Yr 8 Place & Space 35 Disadvantages of Plate Movement Deaths and Destruction: Earthquakes, Tsunamis and Volcanic eruptions 2004 Indian ocean over 225,000 deaths from earthquake and Tsunami 2011 Japan over 15,000 deaths and 10,000 still missing Air traffic stopped - Iceland’s volcanoes

36. CL USB 6 Geography Yr 8 Place & Space 36 Destruction: by tsunamis, earthquakes and volcanic eruptions – –crops and fishing boats –food shortages –Infrastructure roads, rail, airports difficulty getting help to area –Sewerage, industrial, chemical factories destroyed – contamination –Debt rebuilding, and loss of income