1. Mid-Ocean Ridges: The process primarily occurs at mid-ocean ridges, underwater mountain ranges that are sites of volcanic activity.
2. Magma Upwelling: Molten rock, called magma, rises from the Earth's mantle (the layer beneath the crust) towards the surface at these ridges.
3. Crust Formation: The magma cools and solidifies, forming new oceanic crust. This process is called crystallization.
4. Divergent Plate Boundaries: Seafloor spreading occurs at divergent plate boundaries, where tectonic plates are moving apart. As the plates move apart, the magma rises to fill the gap, creating new crust.
5. Convective Motion: This process is driven by the Earth's internal heat and convection currents in the mantle. These currents cause the plates to move, pushing new crust away from the ridge.
Key takeaways:
* New oceanic crust is constantly being formed at mid-ocean ridges.
* Seafloor spreading is a key process in plate tectonics.
* The process is responsible for the expansion of the ocean floor.
