Earths structure worksheet - Earths Structure Worksheet Use ... - Free Printable

Earth's Structure Worksheet Solution

The worksheet is about labeling and understanding the different layers of the Earth. Below is the completed worksheet with explanations for each part.

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#### Earth’s Structure Worksheet

Use information from the following website: to color in the earth and label
- [http://www.learner.org/interactives/dynamicearth/structure.html](http://www.learner.org/interactives/dynamicearth/structure.html)

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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

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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

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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 5000°C.
- Label: Outer Core

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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

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Additional Information

#### 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 solid rock that hold the continents and oceans.
- Label: Solid Rock

#### Asthenosphere
- Description: The plates of the lithosphere move (slowly) on this hot, malleable semi-liquid zone in the upper mantle, directly below the lithosphere.
- Label: Slowly

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How do you think scientists discovered the layers of our Earth?

Explanation:
Scientists discovered the layers of the Earth primarily through the study of seismic waves generated by earthquakes. Here’s how:

1. Seismic Waves:
- When an earthquake occurs, it generates seismic waves that travel through the Earth.
- There are two main types of seismic waves:
- P-waves (Primary Waves): These are compressional waves that can travel through solids, liquids, and gases.
- S-waves (Secondary Waves): These are shear waves that can only travel through solids.

2. Behavior of Seismic Waves:
- As seismic waves travel through the Earth, their speed and direction change depending on the material they pass through.
- Scientists measure the time it takes for these waves to travel from the earthquake's epicenter to various points on the Earth's surface.
- By analyzing changes in wave speed and direction, scientists can infer the composition and structure of the materials they pass through.

3. Key Observations:
- Discontinuities: Sudden changes in wave speed indicate boundaries between different layers.
- Shadow Zones: Certain areas on Earth do not receive S-waves or P-waves, which helps科学家确定液体和固体层的存在。
- Reflection and Refraction: Waves reflect off boundaries and bend as they enter different materials, providing further clues about the Earth's internal structure.

4. Layer Identification:
- Crust: The outermost layer, where seismic waves first originate.
- Mantle: The thick layer beneath the crust, where waves slow down due to higher density.
- Outer Core: Identified by the sudden disappearance of S-waves (since S-waves cannot travel through liquids).
- Inner Core: Identified by the reappearance of S-waves and changes in P-wave speeds, indicating a solid inner core.

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Final Answer

- Labels for the Earth's Layers:
1. Crust
2. Mantle
3. Outer Core
4. Inner Core

- Additional Labels:
- Lithosphere: Solid Rock
- Asthenosphere: Slowly

- Discovery Method: Seismic Wave Analysis

Boxed Final Answer:
\boxed{\text{Crust, Mantle, Outer Core, Inner Core}}