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Inside
Earth
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Introduction:
The earth is a solid mass almost spherical in shape. It is divided
into layers, each of which has a distinct composition. The rocky
outer layer of the earth is called the crust. It is composed primarily
of granite and basalt. The crust covers the entire surface of the
earth. It varies considerably in thickness, from about 6 kilometers
(about 4 miles) below the oceans to about 64 kilometers (about 40
miles) thick beneath mountain ranges on the continents. |
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Beneath the crust is a layer called
the mantle. The mantle is about 2,900 kilometers (1,800 miles)
thick and is composed of hot, melted rock, called magma, that
flows in slow-moving currents. The magma of the mantle is made
up of different minerals than those in the solid rock of the crust.
The distance from San Diego to New York City is approximately
2800 miles by car, 2006 miles to Minneapolis,.Minnesota.
Below the mantle is the solid core. The first 2,240 kilometers
(about 1,400 miles) is the outer core. This is about the same
distance as San Diego to Dallas, Texas by car. The outer core
is made up of dense molten rock composed of iron, nickel, and
silicon. |
The inner core is about 2,2440 kilometers (about 1,540
miles) in diameter and composed of iron and nickel. The diameter
of the inner core is approximately the same length as the distance
from San Diego to Omaha, Nebraska by car. The temperature of
the
inner core is about 6000 oC (about 11,000 oF). Despite the extreme
heat, the inner core is solid due to the intense pressure there.
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Inside Earth: Teacher Notes
Download:
(Abobe Acrobat Reader required--download
free reader)
Print the Inside Earth activity worksheets. |
Supplies: (for a class of 32 students):
- 8 oz red Crayola Model Magic (2 packages)
- 16 oz white Crayola Model Magic (1/2 bucket)
- 4 oz blue Crayola Model Magic (1 package)
- 32 paint brushes
- blue paint in small cups
- brown sand and small trays
- colored pencils
- 32 interior of earth handouts
- 32 pieces of wax paper or sandwich wrap
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Student Activities
Examine a globe:
What does Earth look like?
What are the blue areas?
What are the other colored areas? (land, continents, countries,
and states or regions)
What is underneath the land?
What is underneath the water?
Color a picture of earth's interior
- Hand out a copy of the interior of earth picture to each student.
- Using colored pencils, color and label each of the areas.
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Make
a model of the earth (work in teams of 2)
Give each pair of students the following supplies:
- Two sheets of wax paper (one sheet is needed immediately and
the second is needed once the team splits up and they work as
individuals)
- 1/16 package of blue or yellow model magic (inner core)
- 1/8 package of red model magic (outer core)
- 1 oz of white model magic (mantle)
Procedure
- In a common area, set up 3-4 sand trays.
- Prepare small cups of blue paint (but do not give them to
the students until later.)
- Have each student team roll their blue or yellow model magic
into a ball. This is the inner core of earth.
- Add a uniform layer of red model magic to the outside of their
blue or yellow ball. Now the outer core has been added to the
model.
- Add a uniform layer of white model magic to the now red ball.
This is the mantle of the earth.
- With instructors assistance, use a piece of wire to slice
the finished ball into two pieces. Each student will now work
with 1/2 of the model. The model should look like 3 concentric
circles.
- Use blue paint to paint a thin layer of paint on the outside
of the model. This is your crust. Do not paint over the interior
of earth.
- Review with the students what they have just made.
- If desired, sprinkle a small layer of sand onto the still
wet paint.
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