Oldest child getting food: thank you mom middle child getting food: yesss, im starving
youngest child getting food: i said the blue plate, im not eating that :(

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.