Answer:
The size of the Earth increases each year by 0.83 centimeters.
Step-by-step explanation:
Seafloor spreading is a process that occurs along the divergent boundaries between tectonic plates, if the boundary is in the ocean that is. This process has actually been one of the most, if not the most important when it comes to supporting and proving the plate tectonics theory. What happens basically is a more than usual activity in the upper mantle manages to create too much pressure and pushes more magma through, resulting in the breaking up of a plate.
With the plate being broken up, the two newly formed crustal pieces now move away from each other, opening a gap between them. This gap is constantly filled with enormous amounts of magma, creating mid-ocean ridges. The ridges are the highest at the boundary itself, as well as being the hottest, and the further away we move away from the boundary they are older, cooler, and smaller. The formation of the new crust is also a very good indicator of the positions of the north and south pole, as the rock is preserving stripes caused by magnetism during its formation.