Sea Floor Spreading

Question 1

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

Answer 1

Normal and reversed magnetism

Question 2

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

Answer 2

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

Question 3

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

Answer 3

The spinning of the core

Question 4

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

Answer 4

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

Question 5

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

Answer 5

Paleomagnetism

Question 6

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

Answer 6

The geographical North because it is attracted the the magnetic South

Question 7

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

Answer 7

The iron particles in the magma

Question 8

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

Answer 8

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

Question 9

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

Answer 9

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