What causes the formation of mountains and valleys on the ocean floor?
Like the relaxation of the Earth, the ocean floor is divided into tectonic plates. The movement of these plates is responsible for features like ridges, trenches, and valleys. Ridges are fashioned when two plates drift apart. Boiling rock from internal the Earth, called magma, oozes out via the cracks between the plates and cools to form a ridge. Trenches are shaped when a heavier plate sinks down below a lighter one.
