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Flashcards in Sea Floor Spreading Deck (9)
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What alters every 400,000 years on earth? (S.F.S tectonics)

Normal and reversed magnetism


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


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

The spinning of the core


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)


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



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

The geographical North because it is attracted the the magnetic South


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

The iron particles in the magma


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


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