Quick Answer: What Is Seafloor Spreading?

Who discovered seafloor spreading?

Harry HessHarry Hess: One of the Discoverers of Seafloor Spreading main content..

What is the difference between seafloor spreading and continental drift?

Continental drift is a very similar process to seafloor spreading. Continental drift is the gradual movement of continental plates over the Earth’s surface over time. … Seafloor spreading is the formation of new areas of oceanic crust due to the upwelling of magma as oceanic aparts pull apart.

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.

What causes tectonic plates to move?

The heat from radioactive processes within the planet’s interior causes the plates to move, sometimes toward and sometimes away from each other. This movement is called plate motion, or tectonic shift.

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.

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.

When did seafloor spreading start?

The discovery of the Great Global Rift in the 1950s inspired him to look back at his data from years before. 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.

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 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.

How old is the seafloor?

150 million yearsVery little of the sea floor is older than 150 million years. This is because the oldest sea floor is subducted under other plates and replaces by new surfaces. The tectonic plates are constantly in motion and new surfaces are always being created.

What is the first step of seafloor spreading quizlet?

1. A long crack in the oceanic crust forms at a mid ocean ridge. 2. Molten material rises and erupts along 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.

What is seafloor spreading theory?

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. As the plates move apart, new material wells up and cools onto the edge of the plates.

What is seafloor spreading quizlet?

Seafloor Spreading. The process by which molten materials add new oceanic crust to the ocean floor. Only $2.99/month. Deep Ocean Trench. A deep valley along the ocean floor beneath which oceanic crust slowly sinks toward the mantle.

What does seafloor spreading look like?

Seafloor spreading is a geologic process in which tectonic plates—large slabs of Earth’s lithosphere—split apart from each other. Seafloor spreading and other tectonic activity processes are the result of mantle convection. … The less-dense material rises, often forming a mountain or elevated area of the seafloor.

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 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.

Where is seafloor 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.

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.

Where does seafloor spreading occur quizlet?

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