In the mantle, heat is transferred as soft rock flows slowly in cycles known as ______ currents.

In the mantle, heat is transferred as soft rock flows slowly in cycles known as convection currents. convection currents are the currents that are caused due to the process of convection. It is actually one of the three main process of heat transfer. The other two process of heat transfer are conduction and radiation. 

the answer is convection currents