The Layers of the Earth

The Earth may look solid and unchanging, but deep beneath our feet it is made of several different layers, each with its own characteristics. Scientists have discovered these layers by studying earthquakes, volcanoes, and rocks from deep underground.

The outermost layer is the crust. It is the thinnest layer, like the skin of an apple. The crust is where we live, and it includes mountains, valleys, oceans, and continents. Even though it is thin compared to the other layers, it is very important because it supports all life.

Beneath the crust is the mantle, the thickest layer of the Earth. The mantle is made mostly of solid rock, but it is so hot that parts of it can slowly flow, almost like thick soup. This movement causes the crust above it to shift, leading to earthquakes and the formation of mountains.

Next is the outer core, made of liquid iron and nickel. The movement of these hot, liquid metals creates Earth’s magnetic field, which protects us from harmful rays from the sun.

At the very center is the inner core. It is a solid ball made mostly of iron. Even though the temperature there is hotter than the surface of the sun, the inner core remains solid because of the enormous pressure surrounding it.

The study of Earth’s layers helps scientists understand how our planet formed and how it continues to change over time. Without this knowledge, we would not fully understand earthquakes, volcanoes, or even the land we live on today.

Vocabulary Words
_____1. the thin, outer layer of the Earth
              where we live.

_____2. the thick, middle layer of Earth
              made of very hot rock.

_____3. the liquid layer beneath the
              mantle, made of iron and nickel

_____4. the solid center of Earth, made
              mostly of iron

_____5. the force that pushes on
              something from all sides

_____6. an invisible shield around Earth
              created by the movement of
              metals in the outer core,
              protecting us from the sun’s
              harmful rays.

_____7. features or qualities that make
              something different or special

_____8. the way something is made or 
              developed.

Comprehension Questions
A. Recall and Understanding

1. What is the crust, and why is it  
    important?

2. Describe the mantle and explain what
    its movement can cause.

3. What creates Earth’s magnetic field,
    and why is it important?

4. Why does the inner core stay solid
    even though it is extremely hot?

B. Higher-Order Thinking

5. How does studying the layers of Earth
    help scientists understand
   earthquakes and volcanoes?

6. If the Earth’s magnetic field
    disappeared, what might happen to  
    living things?

7. Imagine if the mantle stopped
    moving—what changes might occur  
    on the Earth’s surface?