earths interior andie

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•What does the inside of the Earth look like?

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Page 1: Earths Interior  Andie

•What does the inside of the Earth look like?

Page 2: Earths Interior  Andie

How do we determine the composition of the Earth?

• Scientists cannot see the interior so they must use other ways to figure it out!

• Earthquakes have many different types of waves• These waves travel at different speeds

through solids and liquids • Some waves don’t travel at all through

liquids.• Measuring these waves tells us what is in the

Earth’s core and where the materials change.

Page 3: Earths Interior  Andie
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Earth Layers

• The Earth is divided into four main layers.

*Inner Core*Outer Core*Mantle *Crust

Page 5: Earths Interior  Andie

The Earth’s Crust• The crust is the thinnest layer on Earth

• There are two types of crust

• Oceanic crust – made mostly of the igneous rock basalt. Found under the ocean. Relatively thin.

• Continental crust – made mostly of granite. Found under the continents. Relatively thick.

Page 6: Earths Interior  Andie

Special parts of the Crust

• Lithosphere• Crust is the upper part of the lithosphere• Broken up into large plates

• Asthenosphere• Upper part of mantle, below lithosphere • 130 – 160 km thick• Cooler part of the mantle that the

lithospheric plates slide on top of.

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The Earth’s Mantle• Located directly above the outer core

• Starts below the crust

• Is the largest layer

• 80% of the Earth’s volume & 68% of Earth’s mass

Page 10: Earths Interior  Andie

The Earth’s Mantle• Composed of more iron than the crust.

• Density, pressure, and temperature all increase the deeper you go in the mantle

• Temperature ranges from 870 C – 2200 C

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Special layers of the mantle

• Lithosphere – crust plus the upper, solid part of the mantle. Forms plates.

• Asthenosphere – just under the lithosphere. Slow moving “Silly putty” layer on which the lithospheric plates slid. (Solid rock that flows very slowly.)

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Currents in the Mantle

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The Earth’s Core

The Earth’s Core• Composed of the inner and outer

core• Both are made of iron and nickel

Page 16: Earths Interior  Andie

•How do scientists know that there is a solid inner core?

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The Earth’s Outer CoreThe Outer Core - Liquid• Surrounds the inner core

• Temperature ranges from 2200 C – 5000 C near inner core

• Molten (liquid) iron and nickel

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The Earth’s Inner CoreThe Inner Core - Solid• Temperature reaches 5000 C

• Solid iron and nickel • Usually both would be liquid but are solid in

the core because of the incredible pressure

• The solid core is the source of Earth’s magnetic field

Page 21: Earths Interior  Andie

What do you know about these layers?