According to Plate Tectonics
theory, there are seven large plats on the Earth’s crust that are moving on a
large scale, creating the phenomenon called continental drift. The reason why
oceans do not become bigger is that the old crust is destroyed as it goes under
in the subduction zones and to the mantle. According to estimates, the Atlantic
Ocean is spreading, but the Pacific Ocean is not since it is undergoing
subduction in many of its boundaries.
