what causes the ocean floor to spread

In essence, oceanic plates are more susceptible to subduction as they get older. Because of this correlation between age and subduction potential, very little ocean floor is older than 125 million years and almost none of it is older than 200 million years.

What are three causes of plate movement?

Mantle dynamics, gravity, and Earth’s rotation taken altogether causes the plate movements. However, convectional currents are the general thought for the motion.

What force causes most of the plate movement?

Research has shown that the major driving force for most plate movement is slab pull, because the plates with more of their edges being subducted are the faster-moving ones. However, ridge push is also presented in recent research to be a force that drives the movement of plates.

What causes the tectonic plates to move quizlet?

convection currents are a process in which the materials inside the mantle heat up and rise to the surface whilst the cooler liquid sinks; as it sinks it then heats up and rises again. This continuous cycle is established: hot liquid rising, cold liquid descending. These currents cause the tectonic plates to move.

What is the major evidence that sea-floor spreading creates new lithosphere explain your answer?

The record of magnetic reversals is carried away from each side of the spreading center of a mid-ocean ridge, showing that the molten rock is creating new lithosphere.

Which of the following is a result of sea-floor spreading?

In sea-floor spreading, the sea floor spreads apart along both sides of a mid-ocean ridge as new crust is added. As a result, the ocean floors move like conveyor belts, carrying the continents along with them. … Yet some areas of the deep-ocean floor are teeming with life. One of these areas is the East Pacific Rise.

What causes magnetic stripes on the seafloor quizlet?

Why does the rock of the ocean floor have a pattern of magnetic stripes? The rock of the ocean floor contains iron. As molten material cooled and hardenend, the iron bits inside lined up in the direction of Earth’s magnetic poles, creating a pattern of magnetized stripes.

What are three kinds of evidence of the ocean floor spreading?

Several types of evidence from the oceans supported Hess’s theory of sea-floor spreading-evidence from molten material, magnetic stripes, and drilling samples.

How was sea-floor spreading tested as a hypothesis?

Since the oldest oceanic crust was found at the edges of the trenches, Hess hypothesized that the seafloor subducts into Earth’s interior at the trenches to be recycled in the mantle. As oceanic crust forms and spreads, moving away from the ridge crest, it pushes the continent away from the ridge axis.

What causes new material to form at a mid-ocean ridge on the ocean floor?

A mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, formed by plate tectonics. This uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.

How did Vine and Matthews relate the sea floor spreading hypothesis to magnetic reversals of the Earth’s poles?

Vine and Matthews observed that there were symmetrical bands of rocks with similar polarities on each side of every mid-ocean ridge. They hypothesized that the reverse polarized rocks formed at the ridges during the geologic past when the earth’s magnetic field had reverse polarization.

What causes polar wandering?

True polar wander represents the shift in the geographical poles relative to Earth’s surface, after accounting for the motion of the tectonic plates. This motion is caused by the rearrangement of the mantle and the crust in order to align the maximum inertia with the current rotation axis (fig.

What causes continents to move Hess?

Photo: Harry Hess argues that the continents had once been one, and have drifted apart. … After much thought, he proposed in 1960 that the movement of the continents was a result of sea-floor spreading. In 1962, he added a geologic mechanism to account for Wegener’s moving continents.

What is the primary reason that oceanic crust subducts beneath continental crust?

When an oceanic plate converges with a continental plate, the oceanic crust will always subduct under the continental crust; this is because oceanic crust is naturally denser. Convergent boundaries are commonly associated with larger earthquakes and higher volcanic activity.

What causes subduction?

Subduction occurs when two plates collide at a convergent boundary, and one plate is driven beneath the other, back into the Earth’s interior. … When an oceanic plate collides with a continental plate, the denser oceanic plate is bent downward and slides under the edge of the continent.

What causes the subduction of one of the oceanic plates?

When an oceanic and a continental plate collide, eventually the oceanic plate is subducted under the continental plate due to the high density of the oceanic plate. Once again a benioff zone forms where there are shallow intermediate and deep focus earthquakes.

How is the ocean floor destroyed?

You are correct that the seafloor is destroyed at subduction zones, but it is simultaneously being created at mid-ocean ridges. see figure 1 . Figure 1: Seafloor spreading at a mid-ocean ridge(where new crust is being created) and it’s destruction at a subduction zone.