Which ocean process creates new seafloor at mid-ocean ridges?

Seafloor spreading creates new seafloor at mid-ocean ridges.

At a mid-ocean ridge, tectonic plates move apart and hot mantle material rises beneath them. The molten rock cools to form new oceanic crust, mainly basalt. As more magma arrives, older crust is pushed away from the ridge on both sides.

The pattern of magnetic stripes on the seafloor provided strong evidence for this process. As basalt cools, iron-bearing minerals record the direction of Earth’s magnetic field. Because the field has reversed repeatedly, matching bands occur symmetrically on opposite sides of many ridges.

Seafloor spreading is part of plate tectonics and helps explain why ocean basins are geologically young compared with most continental rocks. New crust is eventually recycled at subduction zones, where one tectonic plate sinks beneath another. The process is different from ocean currents, tides or ordinary coastal erosion, which move water or sediment without creating oceanic crust.