Seafloor spreading occurs at the boundary between two tectonic plates. As the plates divide, magma comes up through the crack and cools to form new sea floor. The farther away the floor is from the boundary, the older it is.
At divergent plate boundaries the spreading of the tectonic plates results in the reduced pressure of the underlying magma. As the spreading continues, lava fills in the area of spreading and cools, becoming the newest addition to the seafloor. This process occurs at a steady rate ranging from a few centimeters to several centimeters of new sea floor each year. However, at a different location opposite the newly formed seafloor are convergent plate boundaries where land and seafloor is destroyed to make room for new seafloor.
seafloor spreading by Harry Hess
Seafloor spreading at mid ocean ridges produces magma and later igneous rocks that are mostly basaltic. Being a mafic rock, it ejected from a mid ocean ridge so it is extrusive. Often it is aphanitic and visicular. Basalt is most common on sea floors because the magma that is melted is comprised of mostly mafic rocks.
im sorry i do not know the answer but if ur single im free
Hot material ascends at the ridge axis form the mantle. It partially melts. The basaltic melts ascend and form 6-7 km of oceanic crust. The seafloor and the underlying mantle then move away from the ridge axis. The material cools from top down. As it does it contracts thermally and becomes more dense. The vertical contraction of the material and the increased load on the underlying mantle causes the seafloor to subside. The weight of the overlying water also causes subsidence. To the first order, the predicted depth to the seafloor increases with the square root of age from the ridge axis. This in fact occurs and was strong evidence for the reality of seafloor spreading in the late 1960s. Note that Lord Kelvin was on the trans-Atlantic cable project. He crossed the Charlie-Gibbs fracture zone rather than the ridge axis. The square-root relationship was not evident. Wegener also considered the process to some extent, but ended up with continents moving as rafts rather than with seafloor spreading. See paper for technical derivation and some early references. 2011 Sleep, N. H., Small-scale convection beneath oceans and continents. Chi. Sci. Bull., 56(13), 1292-1317, DOI: 10.1007/s11434-011-4435-x.
No, seafloor spreading does not hold the plates in place. Seafloor spreading is a process that occurs at mid-ocean ridges where new oceanic crust is formed and spreads apart. It is driven by the movement of tectonic plates, which are actually responsible for holding the seafloor in place.
One example would be...the mid-atlantic ridge.
One example would be...the mid-atlantic ridge.
2. Mid Ocean Ridges are the place where new crust is formed. 1. oceanic plates or oceanic crust
The age of rocks gets progressively younger as you move away from the mid-ocean ridges, where seafloor spreading occurs. This supports the theory of seafloor spreading, as new crust is being formed at the ridges and then moves away from them over time. This process leaves a record of older rocks further from the ridges and younger rocks closer to them.
Seafloor spreading is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. Seafloor spreading helps explain continental drift in the theory of plate tectonics.
Mid-oceanic ridges
They proved that the seafloor was spreading.
When seafloor spreading occurs, it pushes the underground magma up though the new crust, creating a sort of volcano out of the new crust. Magma is a very important part in seafloor spreading. :]
A diagram that shows how seafloor spreading works.
Seafloor spreading explained WHY and how Continental Drift occurs. How can lands be 'moving' without a catastrophic or even noticeable change--- seafloor spreading accounts for these small changes. It identifies where the actual changes take place (even if we cannot identify the exact spots where spreading occurs). We can better estimate how much the "spreading" equates to observable/measurable changes of continents, specifically how fast (slowly) continents are moving closer or further apart. Seafloor spreading explains other phenomena, too, like the expulsion of methane gas pockets at the ocean floor which are suspected to interfere with flotation of ships and possibly the downing of airplanes that pass over where methane is released when methane gas disrupts the air above the water. Seafloor spreading also gives clues as to how mountains and valleys form underwater and on land.
Seafloor spreading is triggered by a rift in a continental land mass.