Copositional convection in the outer core

Question 1

What are there regions of in outer core?

Answer 1

Downwelling and upwelling

Question 2

Where does heat go?

Answer 2

Heat from the inner core reaches the surface via the outer core

Question 3

What happens in terms of freezing? What does it depend on? What does it cause?

Answer 3

Freezing in general terms inside the earth depends on the pressure and impurity content- anything in the outer core that is not iron. Freezing in the outer core will cause the colder and denser materials to sink until it reaches the outer layer of the inner core

Question 4

What does solidification do?

Answer 4

Solidification at the outer-inner core boundary separates dense iron, which stays there, from residual less dense ‘impurities’

Question 5

What happens to impurities?

Answer 5

Impurities are lighter and buoyant so they will rise upwards towards outer core

Question 6

What does this result in?

Answer 6

Results in a cycle/convection in the fluids outer core

Question 7

What does it create?

Answer 7

Creates earth’s magnetic field and causes substantial heat loss from the core

Question 8

What happens to outer and inner core?

Answer 8

Outer core grows at the expense of inner core over time and inner core becomes lopsided