What phenomenon involves Earth's plates splitting apart and causing more rock to erupt to the ocean floor?

Seafloor spreading is the phenomenon where tectonic plates split apart, leading to the formation of new oceanic crust as magma rises from the mantle and solidifies at mid-ocean ridges. This process occurs at divergent plate boundaries, where the movement of the plates away from each other allows magma to flow up and create new rock on the ocean floor.

As the tectonic plates continue to move, the newly formed rock pushes older rock away from the ridge. This process not only contributes to the expansion of ocean basins but also plays a significant role in the cycling of Earth's materials and the geological dynamics of the planet. Seafloor spreading is a critical aspect of plate tectonics, emphasizing the interconnected nature of Earth's crust and the constant change it undergoes.

Other processes listed, such as subduction and rifting, refer to different geological activities involving tectonic plate interactions and do not specifically describe the creation of new ocean floor resulting from plates splitting apart.