Here's a breakdown:
* Mid-ocean ridges are underwater mountain ranges formed by the upwelling of magma from the Earth's mantle.
* Sea-floor spreading is the process where new oceanic crust is created as magma rises to the surface at the ridge, cools, and solidifies.
* This process results in the divergence of tectonic plates, pushing them apart.
* As the plates move away from each other, the gap created is filled with new oceanic crust, effectively widening the ocean basin.
Key aspects of sea-floor spreading:
* Magma upwelling: Molten rock (magma) from the mantle rises to the surface at the ridge.
* Crust formation: As magma cools and solidifies, it forms new oceanic crust.
* Magnetic striping: The new crust acquires the Earth's magnetic signature at the time of its formation, resulting in a pattern of alternating magnetic stripes on the ocean floor.
* Plate movement: Sea-floor spreading drives the movement of tectonic plates, which in turn shapes the Earth's surface.
