Transfer of heat from earth's core to earth's surface

Question 1

What does heat transfer function like?

Answer 1

Functions like a kettle. The stove element heats the kettle, and the kettle heats the water by conduction. Water circulating in the kettle transfers heat by convection due to heat transfer by radiation. Heat advection when water is poured out of the kettle- process that occurs in the earth as well

Question 2

What is poorly understood in the earth?

Answer 2

Processes of thermal or thermochemical convection in the earth are still poorly understood

Question 3

How might thermal convection work?

Answer 3

Imagine a parcel of rock at the base of the mantle is heated up by heat flow from the outer core. It now has a temperature higher than the rock around it, and hence it begins to rise. It will eventually rise to the top. This displaces the colder material above it, which will be pushed downwards and thus be colder than the surrounding material. Once this starts, it will therefore keep sinking. This will support a convection mechanism by which anomalously hot material will rise and relatively cool material will sink

Question 4

What are the two main processes by which heat may conduct in earth?

Answer 4

Transfer of electrons along the thermal gradient (hotter –> colder)
Vibration of atomic lattices (phonons)

Question 5

Why is transfer of electrons important?

Answer 5

Faster mechanism
Important in good electrical conductors
Therefore, significant in the earth’s core

Question 6

Why is vibration of atomic lattices important?

Answer 6

Slower mechanism
Important in poor electrical conductors
Therefore, a supplementary mechanism of heat transport in lithosphere and mantle