The interior of the earth can be divided into 3 different layers – crust, mantle, and core. The crust is the outermost layer of the earth, and the core is the innermost layer of the earth, located at a depth of 2900 Km. This article briefly throws light on these 3 different interior layers of the earth.

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Structure of the Earth

Earth_internal_structure

The Crust
The Mantle
The Core

The Crust

The crust is the outermost solid part of the earth.
It is fragile.
The thickness of the crust varies under the oceanic and continental areas.
Oceanic crust is thinner as compared to the continental crust.
The continental crust is thicker in the areas of major mountain systems.
The crust is made up of heavier rocks having a density of 3 g/cm3.
The kind of rock seen in the oceanic crust is basalt.
The mean density of material in the oceanic crust is 2.7 g/cm3.
Silica (Si) and Aluminium (Al) are major constituent minerals. Hence it is often termed as SIAL. Also, sometimes SIAL is used to refer to the Lithosphere.

The Mantle

The portion of the interior beyond the crust is called the mantle.
It is in a solid-state.
It has a density higher than the crust portion.
The thickness ranges from 10-200 km.
The mantle extends from Moho’s discontinuity to a depth of 2,900 km.
The asthenosphere is the upper portion of Mantle.
It is the chief source of magma that finds its way to the surface during volcanic eruptions.
The crust and the uppermost part of the mantle are called the lithosphere.
The major constituent elements of the mantle are Silicon and Magnesium and hence it is also termed as SIMA

The Core

The core-mantle boundary is positioned at the depth of 2,900 km.
The inner core is in the solid-state whereas the outer core is in the liquid state.
The core is made up of very heavy material mostly constituted by nickel and iron. Hence it is also called the “nife” layer.

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Frequently Asked Questions related to Interior of Earth

What are the 4 different layers of the earth?

The 4 different layers of earth are, from deepest to shallowest, the inner core, the outer core, the mantle and the crust. Except for the crust, no one has ever explored these layers in person.

How does the interior of the Earth affect its surface?

The temperature in the core is hotter than the Sun’s surface. This intense heat from the inner core causes material in the outer core and mantle to move around. The movement of material deep within the Earth may cause large plates made of the crust and upper mantle to move slowly over the Earth’s surface. It is also possible that the movements generate the Earth’s magnetic field, called the magnetosphere.

Why is the interior of the Earth hot?

The interior of Earth is very hot (the temperature of the core reaches more than 5,000 degrees Celsius) for two main reasons: The heat from when the planet formed, The heat from the decay of radioactive elements.

What are the discontinuities in the interior of the earth?

Conrad Discontinuity: Transition zone between SIAL and SIMA, Mohorovicic Discontinuity: Transition zone between the Crust and Mantle, Repiti Discontinuity: Transition zone between Outer mantle and Inner mantle, Gutenberg Discontinuity: Transition zone between Mantle and Core, Lehman Discontinuity: Transition zone between Outer core and Inner core.

Which is the hottest layer of the earth?

The inner core is the hottest layer, above 9000 Fahrenheit and it is 1250 km thick!.

What is underneath bedrock?

Bedrock is the hard, solid rock beneath surface materials such as soil and gravel. Bedrock also underlies sand and other sediments on the ocean floor. Bedrock is a consolidated rock, meaning it is solid and tightly bound. Overlying material is often the unconsolidated rock, which is made up of loose particles.

How deep is the centre of the Earth?

The distance to the centre of the Earth is 6,371 kilometres (3,958 mi), the crust is 35 kilometres (21 mi) thick, the mantle is 2855km (1774 mi) thick — and get this: the deepest we have ever drilled is the Kola Superdeep Borehole, which is just 12km deep.

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