The magma flows out of the crack, cools down and becomes the new seafloor. Hot, less dense material form below the earth's crust rises towards the surfaces of the mid-ocean ridge.
Mid-ocean ridge
Deep-ocean Trench
The process of seafloor spreading allowed the creation of new bodies of water.
This material flows sideways carrying the seafloor away from the ridge and creates a crack in the crust.
Overtime, the new oceanic crust pushed the old oceanic crust far from the ridge. Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.