Earth Science

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Transcript Earth Science

The Earth’s Magnetic
Earth is like a bar magnet
The Earth’s Magnetic Field
protects us from Solar Wind
stream of
particles that
destroy life
on earth
between solar wind and
earth’s atmosphere can be seen
near the north & south pole in the
form of Aurorae
What causes our Magnetic Field?
The Dynamo Theory:
►Rotation of the earth causes liquid
rock in outer core to spin
►Moving electrons from the iron &
nickel creates an electric current
►Electric currents produce magnet
fields (Faraday’s Law)
make an electromagnet: you
only need flowing electrons that
surround an iron core
magnetic field changes
through time, due to changes in
the flow of molten currents
How do we know it changes?
a certain temperature, rocks
will “record” the direction of the
magnetic field