Question: What Causes Seafloor To Spread?

Where is active seafloor spreading today?

Where is active sea floor spreading occurring today.

Seafloor spreading is the movement of old rock that is being pushed by the new young oceanic crust.

This would be a divergent since the plates are separating from each other.

Active seafloor spreading is occurring at mid-ocean ridges..

What boundaries destroy seafloor?

At which type of boundary is seafloor destroyed? The seafloor is destroyed at a COnvergent Boundary.

Do earthquakes cause seafloor spreading?

Scientists in Japan study stress released by oceanic earthquakes in newborn sections of seafloor. … Volcanic activity causes the seafloor to spread along oceanic ridges, forming new areas of crust and mantle. After being generated, this new oceanic lithosphere cools down and contracts by up to 3% of its own volume.

What happens to the seafloor at trenches?

Trenches are formed by subduction, a geophysical process in which two or more of Earth’s tectonic plates converge and the older, denser plate is pushed beneath the lighter plate and deep into the mantle, causing the seafloor and outermost crust (the lithosphere) to bend and form a steep, V-shaped depression.

Why seafloor spreading is like a moving conveyor belt?

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.

What is the first step in seafloor spreading?

Sea-Floor Spreading begins at a mid-ocean ridge, which forms along a crack in the oceanic crust. along the ridge, molten material that forms several kilometers beneath the surface rises and erupts. at the same time, older rock moves outward on both sides of the ridge.

What is the major evidence that seafloor spreading creates new lithosphere?

When the Earth’s magnetic field reverses, the magnetized minerals align in the opposite direction. 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.

Does the Earth get bigger because of seafloor spreading?

New crust is continually being pushed away from divergent boundaries (where sea-floor spreading occurs), increasing Earth’s surface. But the Earth isn’t getting any bigger.

What causes seafloor spreading and continental drift?

Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere. … At a spreading center, basaltic magma rises up the fractures and cools on the ocean floor to form new seabed.

What causes seafloor spreading quizlet?

During sea-floor spreading, magma erupts along a mid-ocean ridge to form new oceanic lithosphere. The floor then moves away from the ridge, often toward a trench at the edge of the ocean basin. … These strips form a pattern that is the same on both sides of the mid-ocean ridge.

Which mid ocean ridge is spreading the slowest?

The Ridge is named after him, and the name was recognized in April 1987 by SCUFN (under that body’s old name, the Sub-Committee on Geographical Names and Nomenclature of Ocean Bottom Features). The ridge is the slowest known spreading ridge on earth, with a rate of less than one centimeter per year.

Which is the source of new material during the process of seafloor spreading?

Seafloor spreading is the process of molten material from the mantle being pushed upward to the surface of the earth and spreading apart, creating new earth. This process occurs along divergent plate boundaries at areas called mid-ocean ridges .

How is paleomagnetism evidence of seafloor spreading?

Magnetic reversals show up as bands of alternating polarity in the slowly spreading seafloor. … This explanation of magnetic striping by paleomagnetism convinced scientists that new oceanic crust was being continually formed at mid-oceanic ridges. Seafloor spreading was accepted as a reality.

Where is the seafloor spreading apart the fastest?

These age data also allow the rate of seafloor spreading to be determined, and they show that rates vary from about 0.1 cm (0.04 inch) per year to 17 cm (6.7 inches) per year. Seafloor-spreading rates are much more rapid in the Pacific Ocean than in the Atlantic and Indian oceans.

What are the steps in the process of seafloor spreading?

What are the steps in the process of sea floor spreading?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 is the average speed of seafloor spreading?

approximately 5 centimeters a yearThe average speed of seafloor spreading is approximately 5 centimeters a year. This growth rate can be compared to the growth rate of human fingernails (Krupicka). The global ridge system consists of oceanic ridges. Seafloor spreading occurs at these elevated oceanic ridges and has high heat flow and volcanism.

What is the source of magma for seafloor spreading?

Sea-floor spreading — In the early 1960s, Princeton geologist Harry Hess proposed the hypothesis of sea-floor spreading, in which basaltic magma from the mantle rises to create new ocean floor at mid-ocean ridges.

What are the evidence of seafloor spreading?

Several types of evidence supported Hess’s theory of sea-floor spreading: eruptions of molten material, magnetic stripes in the rock of the ocean floor, and the ages of the rocks themselves. This evidence led scientists to look again at Wegener’s hypothesis of continental drift.