What Is The First Step Of Seafloor Spreading

Which is the first step in the seafloor spreading process? A crack forms in oceanic crust

oceanic crust
Oceanic crust is the uppermost layer of the oceanic portion of the tectonic plates. It is composed of the upper oceanic crust, with pillow lavas and a dike complex, and the lower oceanic crust, composed of troctolite, gabbro and ultramafic cumulates. The crust overlies the rigid uppermost layer of the mantle.

https://en.wikipedia.org › Oceanic_crust


What is the process of seafloor spreading for kids?

Seafloor spreading happens at the bottom of an ocean as tectonic plates move apart. … It forms new crust as the plates move away from each other. The new crust then slowly moves away from the ridge. It is a place of earthquakes and volcanos.

What is the process that produces volcanoes at convergent plate boundaries?

If two tectonic plates collide they form a convergent plate boundary. Usually one of the converging plates will move beneath the other a process known as subduction. … The new magma (molten rock) rises and may erupt violently to form volcanoes often building arcs of islands along the convergent boundary.

What does the seafloor spreading theory state?

This process called subduction occurs at the oceanic trenches (figure 6). The entire region is known as a subduction zone. Subduction zones have a lot of intense earthquakes and volcanic eruptions. The subducting plate causes melting in the mantle.


What are the steps of seafloor spreading?

Terms in this set (7)
  • Magma comes out of the rift valley.
  • Magma cools to rock and hardens.
  • Rock is pushed away as new rock is formed at MOR.
  • Oceanic crust and continental crust meet at the trench.
  • Oceanic crust bends down under the continental crust.
  • Gravity pulls rock towards mantle.
  • Rock melts to mantle.

What are the 3 types of seafloor spreading?

There are three types of plate-plate interactions based upon relative motion: convergent, where plates collide, divergent, where plates separate, and transform motion, where plates simply slide past each other.

Which is 1 piece of evidence of seafloor spreading?

Supporting Evidence for Seafloor Spreading

First, samples of the deep ocean floor show that basaltic oceanic crust and overlying sediment become progressively younger as the mid-ocean ridge is approached, and the sediment cover is thinner near the ridge.

What observation first led to seafloor spreading?

Seafloor spreading was proposed by an American geophysicist, Harry H. Hess in 1960. By the use of the sonar, Hess was able to map the ocean floor and discovered the mid-Atlantic ridge (mid-ocean ridge). He also found out that the temperature near to the mid-Atlantic ridge was warmer than the surface away from it.

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