Question: What Is The First Step Of Seafloor Spreading Quizlet?

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..

What is seafloor spreading simple?

Seafloor spreading happens at the bottom of an ocean as tectonic plates move apart. The seafloor moves and carries continents with it. … At the Mid-Atlantic Ridge (and other places), material from the upper mantle rises through the faults between oceanic plates. It forms new crust as the plates move away from each other.

What boundaries can destroy seafloor?

At convergent plate boundaries, oceanic crust is often forced down into the mantle where it begins to melt. Magma rises into and through the other plate, solidifying into granite, the rock that makes up the continents. Thus, at convergent boundaries, continental crust is created and oceanic crust is destroyed.

Who proposed seafloor spreading?

Harry HessHarry Hess was a geologist and Navy submarine commander during World War II. Part of his mission had been to study the deepest parts of the ocean floor. In 1946 he had discovered that hundreds of flat-topped mountains, perhaps sunken islands, shape the Pacific floor.

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.

What is the first step of seafloor spreading?

A crack forms in oceanic crust. Molten rock rises up through oceanic crust. Molten rock solidifies at the center of the ridge.

Where does seafloor spreading occur quizlet?

Where does seafloor spreading occur? This process occurs along divergent plate boundaries at areas called mid-ocean ridges.

Where is active seafloor spreading occurring 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 are the three steps to create new ocean floor?

convergent boundary — plates converge, or come together. … divergent boundary — two plates diverge, or move apart and new crust or lithosphere is formed. transform fault boundary — plates slide past one another with no creation or destruction of lithosphere.

What are the three 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.

What is the process of seafloor spreading and subduction?

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 . … Along other plate boundaries, a process called subduction occurs.

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.

What is the theory of seafloor spreading quizlet?

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. … an undersea mountain chain where new ocean floor is produced.

Why is seafloor spreading important?

Significance. Seafloor spreading helps explain continental drift in the theory of plate tectonics. … At a spreading center, basaltic magma rises up the fractures and cools on the ocean floor to form new seabed. Hydrothermal vents are common at spreading centers.

What are the 4 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 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 are the process of seafloor spreading?

Seafloor spreading is a geologic process in which tectonic plates—large slabs of Earth’s lithosphere—split apart from each other. … As tectonic plates slowly move away from each other, heat from the mantle’s convection currents makes the crust more plastic and less dense.

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.