Magnetic epochs Flashcards
What are the two epochs?
Normal and reversal
What are normal epochs?
where most magnetic events are positive
What are reversal epochs?
Where most magnetic events are negative
What does statistical analysis show?
That the reversal events are completely random
What happens to earth’s magnetic field?
It drifts westwards
How might the drift occur? gyre?
The speculative existence of a gyre in the outer core could drag the magnetic field with it with the jetstream in the earth’s atmosphere. No evidence
How might it occur in instanbility?
Instability in the fluid flow in the outer core may develop and some of these may cause magnetic field reversals. Causes might be thermo-mechanical distriabances at the core-mantle boundary or other discrete events
How might freezing cause the drift?
Freezing of the outer core and slow growth of the inner core makes the outer core smaller and could affect the reversals, speculative
