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Flashcards in Sea Floor Spreading Deck (9)
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1

What alters every 400,000 years on earth? (S.F.S tectonics)

Normal and reversed magnetism

2

When magma rises from the drifting plates, what does the resultant rock have? (S.F.S tectonics)

Iron particles that are polarised to the polarity of the Earth at that time

3

What is the earths magnetic field created by? (S.F.S tectonics)

The spinning of the core

4

What does the earths magnetism do? (S.F.S tectonics)

Protects the earth from solar winds from the sun (has been theorised that Mars was previously like this but core stopped spinning)

5

What is the process of the core spinning known as? (S.F.S tectonics)

Paleomagnetism

6

What does a compass needle point to and why? (S.F.S tectonics)

The geographical North because it is attracted the the magnetic South

7

What polarises in the same way as a compass? (S.F.S tectonics)

The iron particles in the magma

8

How do the iron particles prove sea floor spreading? (S.F.S tectonics)

The stripes are mirrored exactly on either side of the ocean ridge, spreading away from the boundary

9

Why does sea floor spreading occur? (S.F.S tectonics)

As oceanic crust is pulled apart by convection currents, magma fills the gaps, creating new crust