Se Floor Spreading

The mid ocean ridge is the region where new oceanic crust is created.

Se floor spreading. The process of sea floor spreading created the lithosphere under the atlantic ocean. As north america and south america moved away from europe and africa the resulting crack was filled by mantle material which cooled and formed new lithosphere. The process of sea floor spreading. Seafloor spreading occurs along mid ocean ridges large mountain ranges rising from the ocean floor.

The formation of the new crust is due to the rising of the molten material magma from the mantle by convection current. Igneous rocks rise along conduits from the mantle giving rise to volcanic activity in a narrow band along the mid ocean ridges as these cool the basaltic lavas and dykes form the upper part of the oceanic crust and the underlying magma chamber solidifies to. The following features are shown at example depths to scale though each feature has a considerable range at which it may occur. This spreading creates a successively younger ocean floor and the flow of material is thought to bring about the migration or drifting apart of the continents.

The process continues today. The continents bordering the atlantic ocean for example are believed to be moving away from the mid atlantic ridge at a rate of 1 2 cm 0 4 0 8 inch per year thus increasing. Sea floor spreading the theory that the ocean floor is created at the spreading accretionary plate margins within the ocean basins. The mid atlantic ridge for instance separates the north american plate from the eurasian plate and the south american plate from the african plate the east pacific rise is a mid ocean ridge that runs through the eastern pacific ocean and separates the pacific plate from the north american.

That is it explains why the age thickness and density of the oceanic crust increases with distance from the mid oceanic ridge. The theory of sea floor spreading states that new oceanic crust is being formed continuously at mid oceanic ridges while the older rocks move away from the ridge. The rate at which new oceanic lithosphere is added to each tectonic plate on either side of a mid ocean ridge is the spreading half rate and is equal to half of the spreading rate. Seafloor spreading definition a process in which new ocean floor is created as molten material from the earth s mantle rises in margins between plates or ridges and spreads out.

Spreading rate is the rate at which an ocean basin widens due to seafloor spreading. This graphic shows several ocean floor features on a scale from 0 35 000 feet below sea level. Continental shelf 300 feet continental slope 300 10 000 feet abyssal plain 10 000 feet abyssal hill 3 000 feet up from the abyssal plain seamount 6 000 feet.