They'd stop moving.
the convection currents will be set in motion because the heat from the mantle rises and causing it to change Earth's density & force of gravity
Few earthquakes happen in the earths mantle do to the fact that the mantle has a folded deformation. This means that the amount of pressure on the mantle caused it to deform.
They will stop.
because of the folded deformation
The flow of hot rock in earths mantle will stop and Earth's magnetic field will disappear
It has to harden
The convection currents will stop
there are 7 layers in earths mantle.
the convection currents will stop
Volcanism can only occur on planets with a liquid mantle.
the mantle
the earth's mantle is brown