LAYERS OF THE EARTH

EARTH LAYERS LESSON

Directions:

Print the Layers of the Earth reading comprehension passage and questions (see below).

Students should read the passage silently, then answer the questions.  Teachers may also use the text as part of a classroom lesson plan.

Lesson Excerpt

The earth is made up of four different layers. If you are wondering why it has that many layers this is because of its history. There are many historians and geologists that believe the earth wasn't always made up for four layers. Instead, they believe that as the earth cooled as rapidly as it did that the heavier parts of the earth sank into the inside of the world, the lighter, dense materials moved into the middle of the world, and the lightest materials of all rose to the top. This explains why things like rock are on the surface of the earth and the much heavier things like iron are located in the earth's core.

The four layers of the earth are:

• The Crust -- the part of the earth that you live on
• The Mantle -- a hot area that has the ability to flow (think of lava)
• The Outer Core -- the heaviest parts of earth in a hot liquid state
• The Inner Core -- the heaviest parts of earth in a solid state

The Crust

Think of the crust of the earth like you would a peel of a fruit. This area is thin compared to the rest of the item. It is the weakest layer that is usually meant to prevent major damage to the other layers by breaking the fall. The crust of the earth is about 5 miles thick under the oceanic crust and 25 miles thick under the continental crust. This means that under water (oceans) the layer of the earth goes five miles and under solid ground it goes further at twenty-five miles.

There are many different temperatures that are occurring on the crust of the earth. The air you feel right now is the lowest temperature available on the crust. The highest temperature can be as high as 1,600 degrees Fahrenheit. This is the temperature that would allow rocks to melt which would lead into the second layer of the earth. (continued...)