Earth's Interior Structure

Earth's Interior Structure
The Earth is made up of four layers:

• Crust: Solid, outer layer of the Earth (5-40 km)
• Mantle: Molten rock beneath the crust (~2900 km)
• Outer Core: Molten iron layer beneath the mantle (~2250 km)
• Inner Core: Solid iron layer beneath the outer core (~1200 km)

The lithosphere is made up of the crust and the upper most part of the mantle.  Beneath the lithosphere is the melted part of the mantle is called the asthenosphere.  The asthenosphere is not quite liquid or solid.  The asthenosphere is thick and gooey, much like lava.  In fact, lava is the molten rock that erupts from volcanoes, but is called magma when beneath the surface (crust) of the Earth.  Scientists often refer to this thick and gooey texture as plastic, which describes things that are easily shaped or molded.  In case you didn't know, molten = melted (think: molten chocolate cake). 

As you travel toward the center of the Earth from the crust down to the inner core, there are a few trends to note:

• the density of the materials increases
• the pressure increases
• the temperature increases

Why do you think the density (how tightly packed the particles of a substance), pressure, and temperature all increase as you go deeper into the Earth?  On the right is a picture that may help you make an inference before we learn more about the properties of matter in the upcoming weeks.  Who do you think is feeling the most pressure?  Who do you think is feeling the least pressure?  Who do you think is feeling the warmest?  Who is the most squashed?!

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The Different Physical Properties of Earth's Layers
The video below further divides the Earth's four layers (crust, mantle, outer core, inner core) according to their physical properties.  If you have ever wondered if it is possible for someone to dig to the center of the Earth, you'll find the answer below, too!

Model of Earth's Interior
Every year, Ms. Shon's students build scale models of Earth's interior.  Keep in mind that In order to do this, students must understand both the interior structure of Earth, and how to convert units.  Are you ready to design and build a scale model of Earth's interior?  (interior = inside) I hope so!

Assignment
Complete the assignment on Google Classroom.