Why Does The Lithosphere Thicken As It Moves Away From The Ridge As A Result Of Seafloor Spreading?

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Why Does The Lithosphere Thicken As It Moves Away From The Ridge As A Result Of Seafloor Spreading??

Why does the lithosphere thicken as it moves away from the ridge as a result of seafloor spreading? Because it is cooled from above as seawater circulates through the pore spaces and fractures in the rock. … Sediments are very thin near the axes of oceanic ridges but may be several kilometers thick next to continents.

Why does the oceanic lithosphere get thicker with distance away from the oceanic ridges?

Further spreading generates a narrow sea. D.) Eventually an expansion ocean basin and ridge system are created. Explain why oceanic lithosphere subducts even though the oceanic crust is less dense than the underlying asthenosphere.

What happens to the lithosphere as it moves away from the spreading center?

Seafloor Processes

Oceanic lithosphere forms at midocean ridges where hot magma upwells and then cools to form plates as the material moves away from the spreading center. As the plate cools heat flow decreases and the seafloor deepens (Fig. … The heat flow is proportional to the temperature gradient.

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What is the role of the mid-ocean ridge in the movement of the lithospheric plate?

Mid-ocean ridges are the longest largest and most voluminous magmatic environment on Earth. Ridges are the site of new lithospheric and crustal production that may be subsequently subducted into the mantle and recycled or involved in magma-producing dehydration reactions that slowly build up continental crust (Fig.

Why does oceanic lithosphere Subduct even when the oceanic crust is less dense than the underlying asthenosphere?

Why does oceanic lithosphere subduct even though the oceanic crust is less dense that the underlying lithosphere? Oceanic lithosphere subducts because its overall density is greater than that of the underlying mantle.

Why do ocean water depths increase away from the mid-ocean ridges?

Since hot rocks are in a more expanded state and then contract as they cool (as they spread away from the ridge) the midocean ridges stand up high above the surrounding seafloor. The seafloor depth increases with distance away from the midocean ridges.

Is the Earth getting larger and wider when plates drift away from each other?

The earth is not getting larger and wider when plates drift away from each other. As they move they will encounter other plates and end up diving beneath them. … Places where plates collide are called subduction zones. One plate runs over the other forcing it down into the earth’s mantle again.

Is the earth lithosphere thicker at ridges or trenches?

Tectonic activity can shape the lithosphere itself: Both oceanic and continental lithospheres are thinnest at rift valleys and ocean ridges where tectonic plates are shifting apart from one another.

Is continental lithosphere thicker than oceanic?

7.2 Inhomogeneous Cooling/Continents. Continental lithosphere is thicker than its oceanic counterpart and does not subduct. Its crust is also richer in radioactive elements.

What causes the movement of the rocks in the lithosphere?

Plate Tectonics

The lithosphere is divided into huge slabs called tectonic plates. The heat from the mantle makes the rocks at the bottom of lithosphere slightly soft. This causes the plates to move. The movement of these plates is known as plate tectonics.

Why does the transform fault occur in lithosphere?

Most transform plate boundaries occur in the oceanic lithosphere where they connect segments of ridges (spreading centers). … Since the two lithospheric plates slide past one another along the transforms these boundaries are active seismic zones producing numerous shallow eartquakes.

What causes tectonic plates to move?

Tectonic shift is the movement of the plates that make up Earth’s crust. … 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.

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What is lithospheric plates?

A tectonic plate (also called lithospheric plate) is a massive irregularly shaped slab of solid rock generally composed of both continental and oceanic lithosphere. Plate size can vary greatly from a few hundred to thousands of kilometers across the Pacific and Antarctic Plates are among the largest.

Why does the oceanic lithosphere Subduct?

Oceanic lithosphere subducts because its overall density is greater than that of the underlying mantle. … -The oceanic lithosphere is denser than the continental lithosphere so it subducts. That means it gets shoved down underneath the overriding plate.

Where slabs of oceanic lithosphere is subducted?

When oceanic crust converges with continental crust the denser oceanic plate plunges beneath the continental plate. This process called subduction occurs at the oceanic trenches (figure 6). The entire region is known as a subduction zone. Subduction zones have a lot of intense earthquakes and volcanic eruptions.

What is the relationship between the crust and lithosphere quizlet?

What is the relationship between the crust and the lithosphere? All of the crust is contained within a larger layer called the lithosphere.

Why do ocean water depths increase away from the mid-ocean ridges quizlet?

Why do ocean water depths increase away from the midocean ridges? (Check all that apply.) Older oceanic crust is denser and thus sits lower on the asthenosphere. The accumulation of sediments over time adds weight to the seafloor.

What happens as the thickness of the lithosphere grows from zero at mid-ocean ridges to 100km away from mid-ocean ridges?

As the lithosphere moves away from the ridge it thickens via additional cooling becomes denser and sinks deeper into the underlying ductile asthenosphere.

Does water depth decrease as you move away from the mid-ocean ridge?

Water depth decreases as you move away from the mid-ocean ridge. A rift valley may be associated with divergent plate boundaries. Convergent plate boundaries occur when tectonic plates move in opposite directions. Iceland is geologically active because it is located along the mid-Atlantic ridge.

Is the Earth getting wider and larger?

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. … In locations around the world ocean crust subducts or slides under other pieces of Earth’s crust.

What does plate tectonic theory predict about the distribution of volcanoes and earthquakes?

What does plate tectonic theory predict about the distribution of volcanoes and earthquakes? They should be evenly distributed throughout the earth. They should occur primarily along plate boundaries.

Why does the ocean floor break and spread sideways?

Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other heat from the mantle’s convection currents makes the crust more plastic and less dense. The less-dense material rises often forming a mountain or elevated area of the seafloor.

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Where is lithosphere thickest?

Young oceanic lithosphere found at mid-ocean ridges is no thicker than the crust but oceanic lithosphere thickens as it ages and moves away from the mid-ocean ridge. The oldest oceanic lithosphere is typically about 140 km thick.

How thick is the lithosphere?

about 100 km thick
The lithosphere is the outer solid part of the earth including the crust and uppermost mantle. The lithosphere is about 100 km thick although its thickness is age dependent (older lithosphere is thicker).

Where is the lithosphere thickest thinnest?

Explanation: Lithosphere is all the solid part of the Earth’s surface. So the crust and oceanic crust are included up to the upper mantle. The oceanic crust’s depth is up to 8 km up to the upper part of the mantle the lithosphere is at its thinnest.

How does the oceanic lithosphere differ from continental lithosphere in thickness composition and density?

How does oceanic lithosphere differ from continental lithosphere in thickness composition and density? ANS: Oceanic lithosphere is thinner and denser with a more mafic crust (largely basaltic whereas continental crust is granitic).

What is lithosphere How thick is it and what is it made up of?

The lithosphere is composed of both the crust and the portion of the upper mantle that behaves as a brittle rigid solid. The lithosphere is the outermost mechanical layer which behaves as a brittle rigid solid. The lithosphere is about 100 kilometers thick.

What is the difference between oceanic lithosphere and continental lithosphere?

The difference is that the oceanic lithosphere is that which is formed by oceanic crust and residual mantle. … In contrast the continental lithosphere: It is the one that is formed by continental crust and residual mantle. It is what constitutes the continents. It has an average thickness of about 150 km.

What is the lithosphere and tectonic plate?

The lithosphere which is the rigid outermost shell of a planet (the crust and upper mantle) is broken into tectonic plates. … Tectonic plates are composed of the oceanic lithosphere and the thicker continental lithosphere each topped by its own kind of crust.

What is lithosphere in short answer?

Lithosphere is the solid crust or the hard top layer of the earth. It is made up of rocks and minerals. It is covered by a thin layer of soil. It is an irregular surface with various landforms such as mountains plateaus desert plains valleys etc.

Seafloor Spreading

PLATE TECTONICS

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