1. Structure of the earth

2. Earth’s Layers
The Earth's rocky outer crust solidified billions of years ago, soon after the Earth formed.
This crust is not a solid shell; it is broken up into huge, thick plates that drift atop the soft, underlying mantle.

3. The Crust Outermost layer: Named Lithosphere
Lithosphere = crust + upper mantle
The crust is only about 8 kilometers thick under the oceans (oceanic crust) and about 32 kilometers thick under the continents (continental crust).

4. The Mantle
The Mantle is the largest layer of the Earth. The middle mantle is composed of very hot dense rock that flows like asphalt under a heavy weight. The movement of the middle mantle (asthenosphere) is the reason that the crustal plates of the Earth move.
Is responsible for the movement of the Earths plates

5. The Core Below the mantle and to the center of the Earth.
Two Layers of the Core: The Outer and Inner core
Contains large quantities of Iron.

6. The Outer Core
The core of the Earth is like a ball of very hot metals. The outer core is so hot that the metals in it are all in the liquid state. The outer core is composed of the melted metals of nickel and iron.

7. The Inner Core
The inner core of the Earth has temperatures and pressures so great that the metals are squeezed together and are not able to move about like a liquid, but are forced to vibrate in place like a solid.

8. AND THE THEORY OF CONTINENTAL DRIFT
Plate tectonics
Mt Everest is getting higher by 7cm every year for the past 35 million years
Each time someone climbs it they are actually breaking the record because it’s a little bit higher
This is all because of the different plates of the Earth’s crust
AND THE THEORY OF CONTINENTAL DRIFT

9. The Lithospheric Plates
Because the plates are ‘floating’ on the asthenosphere, they move around. This movement is responsible for earthquakes and creating valleys and mountain ranges.
The crust of the Earth is broken into many pieces called plates. The plates "float" on the soft, semi- rigid asthenosphere. Each plate has a name.

10. Mt Everest getting higher is actually specifically Australia’s fault because the plate we are on is constantly moving north
We used to be part of a single plate that contained Australia and Antarctica until it split 65 million years ago (around the time of the dinosaur extinction)
Australia is moving north, Antarctica stayed where it was
Fossils that are 65 million years old on both Australia and Antarctica are identical, but after that time, they became extremely different
There are actually many cases were identical fossils are found on different continents

11. Distribution of Fossils
Plant and animal fossils found on the coastlines of different continents

12. “Puzzle Pieces”
Continents look like they could be part of a giant jigsaw puzzle
When Columbus started drawing maps, the Italians realised that all the continents fit together like a jigsaw
Then they found other evidence that the continents all used to be joined together

13. Continental Drift Theory
Proposed by Alfred Wegener in 1912
250 million years ago, all of the continents were combined into one super-continent called “Pangaea”
The continents gradually
drifted apart to where
they are today!

14. Continental Drift

15. Continental drift flipbook
Each map contains an approximate year
Start with the most recent and colour each continent in a different colour
Work your way back to the oldest map, colouring each landmass in the same colours as the first map
Cut out the flipbook along the dotted lines
Put the pages in order according to date (oldest on top)
Staple the pages on the let side
Answer these questions in your book:
When does Pangea appear to break apart?
When can you identify Laurasia and Gondwana?
When can you first recognise North America? Africa? Australia? India?

16. New Zealand is on two plates, which is why they experience so many earthquakes
Australia’s biggest earthquake occurred about 20 years ago at Meckering in Western Australia

17. Plate boundaries
On the map provided, colour each plate a different colour (DON’T USE RED)
Name each plate
Draw/colour in the location of the Ring of Fire in RED
Glue this map into your exercise book
Answer the following questions in your book underneath the map
Does Australia sit at the edge of a continental plate?
Does the location of Australia mean it will be unaffected by plate tectonic movements? Explain your answer.

18. Plate movement Divergent Convergent Transform Plates are moving apart
New crust is created from the cooling magma as it rushes to the surface
In continental crust, this creates a valley
In oceanic crust, this creates a mid ocean ridge
Plates are coming together and one dives under the other
Crust is destroyed as it returns to the mantle
In a continental crust, this creates a mountain range
With 2 oceanic plates or with a continental and oceanic plate, this creates a subduction zone (volcano)
Plates are slipping past each other
Crust is neither created or destroyed
Stress builds up and is released as an earthquake

19. Divergent Boundaries
Boundary between two plates that are moving apart or rifting
 
RIFTING causes SEAFLOOR SPREADING

20. Features of Divergent Boundaries
Mid-ocean ridges
rift valleys
fissure volcanoes

24. Convergent Boundaries
Boundaries between two plates that are colliding
 
There are 3 types…

25. Type 1 Ocean plate colliding with a less dense continental plate
Subduction Zone: where the less dense plate slides under the more dense plate
VOLCANOES occur at subduction zones

27. Andes Mountains, South America

28. Type 2 Ocean plate colliding with another ocean plate
The less dense plate slides under the more dense plate creating a subduction zone called a TRENCH

30. Aleutian Islands, Alaska

31. Type 3 A continental plate colliding with another continental plate
Have Collision Zones:
a place where folded and thrust faulted mountains form.

34. Transform Fault Boundaries
Boundary between two plates that are sliding past each other
EARTHQUAKES along faults

36. San Andreas Fault, CA