The spreading center is found at top the mid-oceanic ridges, and it is where two plates diverge from one another. The bottom of these ridges is the oceanic depth. The heat flow is the region where hot molten material travels upwards out of a subduction zone and causes seafloor spreading. The greater the size of the spreading center, the more the heat flow that will occur. Moreover, heat flow increases the thickness of the rock at the crust.
