Transcript The structure of the earth and plate tectonics

The structure of the earth
and plate tectonics
Plate tectonics
• Plate tectonics make up the surface on the earth. The place where one
plate meets another is called the plate boundary. Millions of years ago, the
continents we know today were all joined together. This was called
Pangea.
• There is 3 ways plates can move:
• Destructive or colliding plates (moving towards each other)
• Parting or Constructive plates (moving away from each other)
• Transform plate boundaries (moving over/under each other)
• Name 3 plate tectonics.
• If pressure builds up at plate boundaries and is released, what can
happen?
• What plate is Scotland on?
Earths Crust
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The crust of the earth is the layer that we live on.
It is the coolest layer and is the furthest from the earths core.
All life is on the crust.
It is made of solid rock.
So far, we have not found a way to drill through it.
It makes up less than 1% of the earths volume.
On average its about 40 km thick (25 miles).
Why is the crust the only layer with life on it?
Is the crust the smallest the layer in width?
Is it good that the crust is made of solid rock?
What is the technical term for the crust?
The Mantle
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It’s cooler than the core but still too hot to live on.
Its made of iron and some other elements.
It makes up 15% of the earths volume
The convection currents in the mantle layer are what cause the tectonic
plates that make up the crust move
In the mantle, temperatures range between 500 to 900 °C
A convection current is made when the cold magma and hot magma move
along each other, the warmer magma can move up, and the cold down,
this is how the current is made
Why is the mantle hotter than the crust?
What causes earthquakes and why?
Why is there no life in the mantle?
Inner/Outer Core
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The inner and outer core are both liquid layers
The outer core is about 2300km thick (1400miles)
The inner core has a radius of about 1220km (760miles)
The temperature of the outer core ranges from 4,030 °C in the outer
regions to 5,730 °C near the inner core
• The temperature of the inner core is about 5,430 °C
• It is thought that the inner core could even be growing
• Which layer is closer to the very centre of the earth?