What effects do convection currents have on the mantle and crust that would not happen if convection currents didn't exist?

Answer 1

Convection currents keep the mantle moving and that is what moves the plates of the earth during plate tectonics

Answer 2

Without them both the earth’s mantle and the earth’s plates would stop moving resulting in no volcanic activity causing the earth’s crust to heat up and since the surface of the earth was no longer rotating the electromagnetic field that protects us from heat radiation would not be generated.

Answer 3

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