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How does seafloor spreading create new oceanic crust?

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tectonic basins and rift valleys Escarpments of the Great Rift Valley rising above the plain north of Samburu Game Preserve, central Kenya. Beisa oryxes graze in the foreground.

Seafloor spreading is a geological process occurring at divergent plate boundaries, specifically along the global system of mid-ocean ridges. New oceanic crust is created through the following mechanism:

Magma Upwelling: As tectonic plates move apart, the reduction in pressure allows molten material from the Earth’s mantle to rise toward the surface along the ridge crests.12
Cooling and Solidification: This magma fills fractures and erupts onto the seafloor as lava, where it cools and solidifies to form new oceanic crust.34
Lateral Movement: As more magma wells up and solidifies, the newly formed crust is pushed laterally away from the ridge axis in both directions. This continuous process creates a record of increasingly older crust as one moves further from the spreading centre.12

This process is often accompanied by significant volcanic activity and shallow earthquakes as the crust repeatedly rifts and heals. The resulting crust is typically about 6 km thick and composed of basaltic layers, including pillow lavas, sheeted dikes, and gabbro.14