Answer:mantle
Explanation:
Convection current drives the movement of the earth’s rigid tectonic plates in the planet’s fluid molten mantle.
If in a particular place, the convection current rises up towards the surface of the earth crust, the tectonic plates move away from each other. This process is known as seafloor spreading.
The hot magma then rises to the surface of the earth crust, it then cracks and develop in the ocean floor and the magma pushes up and out to form mid ocean ridges.
Mid-ocean ridges are also called spreading centers. They are fault lines where two (2) tectonic plates are moving away from each other.
