Earths Structure Worksheet | PDF | Plate Tectonics | Earth - Free Printable

Problem Overview:

The task is to label the layers of the Earth and fill in the blanks based on the provided information. The worksheet includes a diagram of the Earth's structure and several descriptions of its layers. We need to identify and label each layer correctly.

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Solution:

#### Step 1: Label the Diagram
The diagram shows a cross-section of the Earth with four labeled sections. Based on the descriptions provided, we can identify each layer:

1. Crust: The outermost layer, which is hard and rigid.
2. Mantle: The layer below the crust, divided into upper and lower regions.
3. Outer Core: A liquid layer made mostly of iron and nickel.
4. Inner Core: A solid sphere at the center of the Earth.

So, the labels for the diagram are:
- 1. Crust
- 2. Mantle
- 3. Outer Core
- 4. Inner Core

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#### Step 2: Fill in the Blanks
Now, let's fill in the blanks using the descriptions provided in the worksheet.

##### Section 1: Crust
- Description: Hard and rigid, the Earth’s outermost and thinnest layer. Only a few miles (5 km) thick under the oceans and averaging 20 miles thick under the continents.
- Label: Crust

##### Section 2: Mantle
- Description: Divided into two subregions, upper and lower, this dense layer made of hot semi-rock is located directly below the crust and is about 1800 miles thick.
- Label: Mantle
- Blanks:
- "Divided into two subregions, upper and lower, this dense layer made of hot semi-rock is located directly below the crust and is about 1800 miles thick."
- "The plates of the lithosphere move (slowly) on this hot, malleable semi-liquid zone in the upper mantle, directly below the lithosphere."

##### Section 3: Outer Core
- Description: The only liquid layer of the Earth – a sea of mostly iron and nickel. It is roughly 1800–3200 miles below the surface and about 1400 miles thick. Temperatures reach 6000°C.
- Label: Outer Core
- Blanks:
- "The only liquid layer of the Earth – a sea of mostly iron and nickel."
- "Temperatures reach 6000°C."

##### Section 4: Inner Core
- Description: An extremely hot, solid sphere of mostly iron and nickel at the center of the Earth. It is 3200 to 2 to 3960 miles below the surface and about 750 miles in diameter.
- Label: Inner Core
- Blanks:
- "An extremely hot, solid sphere of mostly iron and nickel at the center of the Earth."

##### Lithosphere
- Description: Made up of the crust and tiny bit of the mantle, this layer is divided into several constantly (very slowly) moving plates of rigid rock that hold the continents and oceans.
- Blanks:
- "This layer is divided into several constantly (very slowly) moving plates of rigid rock that hold the continents and oceans."

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#### Final Answer
Here is the completed worksheet:

1. Crust – hard and rigid, the Earth’s outermost and thinnest layer. Only a few miles (5 km) thick under the oceans and averaging 20 miles thick under the continents.
2. Mantle – Divided into two subregions, upper and lower, this dense layer made of hot semi-rock is located directly below the crust and is about 1800 miles thick.
3. Outer Core – The only liquid layer of the Earth – a sea of mostly iron and nickel. It is roughly 1800–3200 miles below the surface and about 1400 miles thick. Temperatures reach 6000°C.
4. Inner Core – An extremely hot, solid sphere of mostly iron and nickel at the center of the Earth. It is 3200 to 2 to 3960 miles below the surface and about 750 miles in diameter.

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How Scientists Discovered the Layers of the Earth

Scientists discovered the layers of the Earth primarily through the study of seismic waves generated by earthquakes. Seismic waves travel through the Earth at different speeds depending on the material they pass through. By analyzing how these waves reflect, refract, and change speed as they pass through different layers, scientists were able to infer the composition and structure of the Earth's interior. This method is known as seismic tomography.

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Final Answer Box

$$
\boxed{
\text{1. Crust, 2. Mantle, 3. Outer Core, 4. Inner Core}
}
$$