Question

If the sea floor is spreading,why is the Earth not getting bigger?

Answer 1

Because the the sand on the sea for is very compact and the water salt and chemicals make it compact making it stick together and fill up holes or cracks before going anyhere

Answer 2

Well... there actually are areas of the seafloor that are spreading due to tectonic plates moving apart, but there are also places where these plates meet and one slides under the other (subduction zones) as a result, the earth is not getting bigger since these two actions cancel each other out. If that makes any sense.

That’s what I do know, but if you happen to need extra information, please let me know and I can go research it.
Have a great evening!
~Brooke❤️