3. © Oxford University Press 2001 CE - Mountain-building processes

4. © Oxford University Press 2001 S2 - The unstable earth

5. © Oxford University Press 2001 Mountain-building Vs Unstable earth

6. © Oxford University Press 2001 The unstable earth What makes up the earth’s crust Where are the unstable zones on the earth? Why does the crust move? Volcanic eruptions Fold mountains Earthquakes What are the causes of volcanic eruptions & earthquakes?

7. © Oxford University Press 2001 What makes up the earth’s crust?  The earth is made up of 3 layers: crust mantle core  The earth’s crust is made up of __________ and __________. They form the __________ and __________ floors. rocks soil continents ocean

8. © Oxford University Press 2001  There are 3 major zones of earthquakes and volcanic activities: Where are the unstable zones on the earth? Cicum- Pacific belt Mediterranean belt Mid-Atlantic zone

9. © Oxford University Press 2001  The earth’s crust is made up of __________.  Name the plates marked 1 to 7 in the map below. Why does the crust move? plates Eurasian Plate African Plate Indo-Australian Plate Pacific Plate North American Plate South American Plate Antarctic Plate

10. © Oxford University Press 2001  The plates are moving very slowly along _________________. Why does the crust move? plate boundaries

11. © Oxford University Press 2001  The movement of plates is caused by the _______________ of magma in the mantle. Why does the crust move? convection  This process is explained in the theory of _________________. plate tectonics Convection of __________ Two plates move __________ each other Plates move __________ magma towards apart Destructive plate boundary Constructive plate boundary

12. © Oxford University Press 2001 What are the causes of volcanic eruptions? When there is a line of __________ in the earth’s crust, magma escapes to the surface from the mantle. Hot __________, volcanic __________ and __________ are thrown out to the earth surface. weakness magma ashgases eruption __________ in the mantle is under great heat and high pressure. Magma This is called volcanic __________.

13. © Oxford University Press 2001 What are the causes of earthquakes? When the plates move, __________ builds up in them. The plates will break and __________ is released. The earth will shake. This is called _______________. pressure energy earthquake

14. © Oxford University Press 2001 What are the harmful effects of earthquakes? Big waves — __________ Buildings, bridges, roads and railways __________ People are __________ and injured __________ __________ may break out Collapse of dams may cause __________ tsunamis collapse killed Landslide Fire flooding

15. © Oxford University Press 2001 How to reduce the negative impact of earthquakes?  __________ Scientific methods have been developed to predict when and where hazards will occur.  Protection measures Build earthquake-__________ buildings. Build __________ roads and open ________.  Preparation Carry out earthquake __________.  __________ work Better planning for emergency work. Prediction Relief proof widerparks drills

16. © Oxford University Press 2001 What are fold mountains? When plates move together, some rocks in between are compressed and bent. This is called __________. The rocks may be folded up into high mountains. They are known as __________ mountains. fold folding

17. © Oxford University Press 2001 Where are the fold mountains? 1.Name the fold mountains 1 to 4. 2.Fold mountains are usually found at _______________. Alps Himalayas Rockies Andes plate boundaries

18. © Oxford University Press 2001 How are fold mountains formed? The weight changes them into __________.rocks Sand and mud are left between two plates.

19. © Oxford University Press 2001 How are fold mountains formed? The rocks in between are compressed by __________ movement. The rocks are folded up into high __________ mountains. The fold mountain formed here is the ____________. plate fold Himalayas