Matter on earth constantly cycles between the different reservoirs of the earth system. as matter cycles through the earth's reservoirs, what effect does this have on the total amount of matter on earth

The cycles within which earth's matter moves are closed systems. This means nothing is gained or lost from the system; it only changes from one form to the other. The total amount of matter on earth remains the same. Using tectonic plates as an example, divergent boundaries occur where new oceanic crust is being created. New crust is being created and simultaneously the same amount of crust is being destroyed at convergent margins. 

Mantle convection is the process that drives plate tectonics. the theory of plate tectonics states that the crust is divided into plates that float on the semi molten mantle below. the circular motion of the magma as it slowly rises and falls or move though convection cells drags the plates along causing them to move. the heat source in the lamp would represent the earth's core. the core is the source of energy that drives convection in the mantle. the lava represents molten magma under the earth's surface. if the lava lamp had floating pieces they would move as the circular motion of the lava in the lamp as it rises and falls would move them along the surface. these floating pieces would represent pieces of the earth's crust.