Subduction and sea floor spreading are processes that could alter the size and form of the ocean.
Why is the sea floor spreading.
This idea played a pivotal role in the development of the theory of plate tectonics which revolutionized geologic thought during the last quarter of the 20th century.
Using new data analysis techniques nasa scientists have confirmed the earth isn t expanding putting to rest years of rumors that the earth is growing.
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.
Due to this continuous seafloor spreading occurs and makes atlantic ocean floor to be connected to other continental crust making the ocean gets wider over the time.
This seafloor spreading hypothesis had been proposed a few years earlier by harry hess a petrologist at princeton university and robert dietz an oceanographer in the us coast and geodetic survey the federal department that made maps of the oceans and us coastlines.
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.
For instance the atlantic ocean is believed to be expanding because of its few trenches.
Spreading rate is the rate at which an ocean basin widens due to seafloor spreading.
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.
Dietz and hess were among the small handful who really understood the broad implications of sea floor spreading.
Hess went on to say that as the ocean crust spreads and cools over millions.
Spreading rates determine if the ridge is fast intermediate or slow.
If the earth s crust was expanding along the oceanic ridges hess reasoned it must be shrinking elsewhere.
As upwelling of magma continues the plates continue to diverge a process known as seafloor spreading samples collected from the ocean floor show that the age of oceanic crust increases with distance from the spreading centre important evidence in favour of this process.
This theory introduced by harry hess.
Seafloor spreading is a geologic process where there is a gradual addition o.
These age data also allow the rate of seafloor spreading to be determined and they show that rates.
Seafloor spreading is the mechanism by which new seafloor lithosphere is constantly being created at mid ocean ridges.