The seafloor is believed to spread as a result of what process?

The correct answer, which points to convection currents, is rooted in the understanding of how tectonic plates move and interact. Convection currents in the Earth's mantle are responsible for driving the movement of lithospheric plates. These currents, caused by the heat from the Earth's core, create a cycle where hot magma rises towards the surface, cools, and then sinks back down, leading to a continuous motion that affects the position of the plates above.

This process facilitates seafloor spreading, particularly at mid-ocean ridges, where new oceanic crust forms as magma rises to the surface. As these tectonic plates pull apart, they create new seafloor, which expands outward from the ridge. This mechanism highlights the dynamic nature of Earth's geology and the crucial role that convection currents play in the ever-changing seafloor.

Understanding how convection currents relate to plate movement allows for a more comprehensive grasp of the underlying processes that shape the Earth's surface and contribute to phenomena such as earthquakes and volcanic activity.