Study Guide – Earth’s Changing Crust

1)What are the cracks in the Earth’s crust called?  faults

2) What are the four layers of the Earth in order from outer most to inner most? Draw it and label it on the back.

3) What is the thickest layer of the Earth? mantle

4) What is the thinnest layer of the Earth? crust

5) Is the Crust the same thickness throughout?  No, it is thinner under the ocean.

6) What is the consistency of the mantle? Molten rock (magma) liquid

7) What is the inner core made of: solid or molten nickel and iron?

8) What is the name of the instrument that scientists use to measure the movement of the Earth’s crust?  seismograph

9) What are the pieces of the Earth’s crust called?  (Tectonic) plates

10)A force that pulls or stretches the Earth’s crust apart is called __tension__? And this occurs at what type of boundary? __divergent___

11)A force that twists , tears, or pushes the plates past each other is called _shear__? And this occurs at what type of boundary? __transform____

12) A force that squeezes or pushes the crust together is called __compression___? And this occurs at what type of boundary? _convergent__
13) Molten rock below the Earth’s surface is called magma__.
14) Molten rock above the Earth’s surface is called _lava___.
15) _Earthquakes__ and _Volcanoes_ cause fast changes on the Earth’s surface due to release of energy either when plates collide or when they are pulled apart.

16) Define weathering  : the breaking down of rocks, minerals, or the surface of the earth through chemical or mechanical (physical) processes.
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17) What is the difference in chemical weathering and physical weathering?  Give examples of each.   Chemical weathering: chemicals in the air or water change the rock chemically to make it weak or break it down, example is acid rain wearing down the surface of a rock, rust
Physical or mechanical weathering: is the wearing away of rocks through wind, rain, ice or biological things (plants, animals, people)

18) What is erosion? Sediments or soil moving from one place to another through wind, water, or ice.

19) What are some causes of erosion?   Wind, water, ice

20) What is deposition?  Dropping of weathered rock by wind, moving water, or ice 

21) Who is Alfred Wegener? proposed the theory of continental drift, Pangaea, or plate tectonics

22) What is the plate tectonic theory?  Earth’s crust is divided into plates that move around on the top of the mantle

23) Does heat & pressure increase or decrease the deeper you go into the Earth? Why?    Increase because more magma which causes heat and it is trapped under the crust, more weight is on top of you the further down you go

24) What causes the movement of the plates of the crust?  Convection currents cause the mantle to move the plates around

25) Where are most volcanoes and earthquakes located?  Pacific ring of Fire, faults of the Earth (convergent, divergent boundaries and transform boundaries.

26) What are convection currents and what do they cause? Convection currents are caused by the heating and cooling of the mantles when hotter material moves to the top and cooler material sinks to the bottom creating and circular current that causes the crust to move