What is sea-floor spreading?

Sea-floor spreading is the process through which new oceanic crust is formed at mid-ocean ridges as magma rises from the mantle and solidifies. This phenomenon occurs at divergent plate boundaries, where tectonic plates move apart from each other. As the plates separate, magma fills the gap, which cools and solidifies to create new crust. This continuous formation of new crust pushes the older crust away from the ridge, leading to the expansion of the ocean floor over geological time.

Understanding sea-floor spreading is crucial as it explains why ocean basins expand and aids in our comprehension of plate tectonics as a whole. It is essential for explaining various geological features and phenomena, such as earthquakes and volcanic activity associated with the movement of tectonic plates.