Convection cycles in the asthenosphere are primarily driven by the heat transfer from the Earth's interior to the surface. The main driving force behind these convection cycles is the release of heat through radioactive decay of elements within the Earth's core and mantle. This heat causes the materials in the asthenosphere to become less dense and rise towards the surface, while the cooler, denser material sinks back down. This process sets up a continuous circulation pattern that drives the convection cycles in the asthenosphere.
