How Is Seafloor Destroyed?

What happens to old seafloor during the process of its destruction?

The process by which ocean floor sinks beneath a deep-ocean trench and back into the mantle is called subduction (sub duk shun).

As subduction occurs, crust closer to a mid-ocean ridge moves away from the ridge and toward a deep-ocean trench.

Sea-floor spreading and subduction work together..

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.

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 types of plate boundaries?

Plate Boundaries and Hotspot DemonstrationDivergent Plate Boundary. Volcanic eruptions and shallow earthquakes are common where plates rip apart.Convergent Plate Boundary. … Transform Plate Boundary. … Hotspot.

What is it called when new crust is created?

Divergent boundaries — where new crust is generated as the plates pull away from each other. Convergent boundaries — where crust is destroyed as one plate dives under another.

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.

Where does the seafloor get 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.

How is the seafloor produced?

Melting and flowing. Oceanic plates are continuously forged at mid-ocean ridges, an undersea mountain chain created where the edges of two plates are separating. … The new crust is pulled slowly out and away from the ridge as the two plates move apart, making room for molten mantle.

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 happens when two oceanic plates collide?

When two oceanic plates converge, the denser plate will end up sinking below the less dense plate, leading to the formation of an oceanic subduction zone. … Whenever a subduction zone is formed, the subducted plate will end up being partially melted by the earth’s internal magma and molten.

What kind of rock is the seafloor made of?

igneous rockAs old oceanic crust is subducted and melted into magma, new oceanic crust in the form of igneous rock is formed at mid-ocean ridges and volcanic hotspots.

Which boundaries is seafloor destroyed?

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

What are the 2 types of crust?

Earth’s crust is divided into two types: oceanic crust and continental crust. The transition zone between these two types of crust is sometimes called the Conrad discontinuity. Silicates (mostly compounds made of silicon and oxygen) are the most abundant rocks and minerals in both oceanic and continental crust.

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 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.

Is the Nazca Plate subducting?

subduction. The Nazca Plate, which underlies most of the southeastern Pacific, is being subducted beneath most of the west coast of South America at a rapid rate of 80 to 100 millimetres per year.

Who discovered seafloor spreading?

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

What are the 4 types of plate tectonics?

Tectonic Plates and Plate BoundariesConvergent boundaries: where two plates are colliding. Subduction zones occur when one or both of the tectonic plates are composed of oceanic crust. … Divergent boundaries – where two plates are moving apart. … Transform boundaries – where plates slide passed each other.

What are the 4 types of tectonic plate movement?

There are four types of boundaries between tectonic plates that are defined by the movement of the plates: divergent and convergent boundaries, transform fault boundaries, and plate boundary zones.

What is the importance of seafloor spreading?

Significance. 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.

What is the theory of seafloor spreading?

Seafloor spreading, theory that oceanic crust forms along submarine mountain zones, known collectively as the mid-ocean ridge system, and spreads out laterally away from them. …