Question

Which of the following correctly describes seafloor spreading?

Answer 1

Option D correctly describes seafloor spreading. Seafloor spreading is a process which typically occur at middle ocean ridges where new oceanic crusts are formed as a result of volcanic activity. These oceanic crusts then gradually move away from the ridge.

Answer 2

The answer is B. This occurs at mid-ocean ridges, where two tectonic plates are moving away from each other. As they move in opposite directions, the magma from the mantle below rises to fill the void/space left above. As the magma rises, it cools and forms a new crust. This volcanic activity continues as long as the tectonic plates are moving away from each other and new crust is formed spreading outwards from the ridge, with time.