What Causes Sea Floor Spreading

For instance the atlantic ocean is believed to be expanding because of its few trenches.

What causes sea floor spreading.

The seafloor moves and carries continents with it. Seafloor spreading theory that oceanic crust forms along submarine mountain zones and spreads out laterally away from them. The motivating force for seafloor spreading ridges is tectonic plate slab pull at subduction zones rather than magma pressure although there is typically. Which processes change the size and shape of the oceans.

Sea floor spreading is what happens at the mid oceanic ridge where a divergent boundary is causing two plates to move away from one another resulting in spreading of the sea floor. Which evidence causes most scientists to believe that seafloor spreading occurs at the mid atlantic ridge. Gravity causes older denser oceanic crust to sink beneath less dense continental crust. In which earth layer are most convection currents that cause seafloor spreading thought to be located.

A chain of underwater mountains along which sea floor spreading occurs is a. The motivating force for seafloor spreading ridges is tectonic plate pull rather than magma pressure although there is typically significant magma activity at spreading ridges. These age data also allow the rate of seafloor spreading to be determined and they show that rates. As the plates move apart new material wells up and cools onto the edge of the plates.

Seafloor spreading helps to explain continental drift in the theory of plate tectonics. Sea floor spreading and subduction. When oceanic plates diverge tensional stress causes fractures to occur in the lithosphere. 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.

At ridges in the middle of oceans new oceanic crust is created. 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. Oceanic crust on both sides of the ridge shows matching patterns of reversed and normal magnetic polarity. Subduction and sea floor spreading are processes that could alter the size and form of the ocean.

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.