What forms covection currents in the mantle?

Question

what forms covection currents in the Earth's mantle?

Can you explain it will? Thanx thanx!

Answer 1

try this

http://theoryx5.uwinnipeg.ca/mod_tech/no...

Answer 2

Density is related to heat and the less dense material will rise above the less dense material which is a little cooler. You have convection currents.

Answer 3

We know magma is extremely hot but I will be using the terms hot magma and cold magma. By cold magma I mean liquid rock that is cooler in temperature that the liquid rock found deeper in the mantle BUT it is still extremely hot.

The magma deep in the mantle is very hot. Because it is hot is rises just like 'warm air rises  - same principle. The magma closer to the top of the mantle (or closer to the surface) becomes cooler and wants to sink just like 'cool air sinks'.

So what you have is hot magma rising, the cooler magma sinking, it becomes hot so begins to rise and the magma that was how and rose has now cooled so it wants to sink.

The lower hot rises the cooler top sinks back down, it gets hot again so it rises and the cooler magma sinks down - a cycle that repeats over and over and over - convection currents.

Here is a great diagram. They are talking water but it doesn't matter.

http://theory.uwinnipeg.ca/mod_tech/node...

Fig. 8.3