Mid-ocean ridges are places where tectonic plates are spreading apart. This spreading apart causes magma from the mantle to rise up, creating new oceanic crust. Essentially, mid-ocean ridges are divergent plate boundaries where sea- floor spreading continuously forms new crust as the plates move away from each other.

Key Details on Tectonic Activity at Mid-Ocean Ridges

• The tectonic plates at mid-ocean ridges move away from each other, creating a gap.
• Magma rises through this gap due to upwelling in the mantle, solidifying to form new oceanic crust.
• This process is known as seafloor spreading and leads to continuous renewal of oceanic lithosphere.
• Mid-ocean ridges often have volcanic activity and form rift valleys or volcanic mountain ranges underwater.
• Examples include the Mid-Atlantic Ridge and the East Pacific Rise, with different spreading rates affecting their topography.

Thus, mid-ocean ridges are divergent boundaries where tectonic plates move apart, facilitating new crust creation by magma upwelling.