Download Features of Earth`s Crust, Mantle, and Core

Features of Earth's Crust, Mantle, and Core
Name _____________________________ Class ___________ Date _______________
The three main layers of Earth
are the crust, the mantle, and
the core. These layers vary
greatly in size, composition,
temperature, and pressure.
Pressure results from a force
pressing on an area. The
temperature and pressure
inside Earth increase with
depth.
Earth’s Crust
Earth’s crust is the layer of rock that forms Earth’s outer skin. The crust is a layer of solid rock
that includes both dry land and the ocean floor. The overall composition of oceanic crust is
much like basalt, a dark rock that has fine grains. Overall the composition of continental crust is
much like granite, a rock that usually is a light color and has coarse grains.
Earth’s Mantle
The solid material of the mantle is a layer of hot rock. Earth’s mantle is made of rock that is very
hot, but solid. Scientists divide the mantle into layers based on the physical characteristics of
those layers. Overall, the mantle is nearly 3,000 kilometers thick. Geologists often group the
crust and uppermost mantle into a single layer called the lithosphere. The soft layer just
beneath the lithosphere is called the asthenosphere.
Earth’s Core
The core is made mostly of the metals iron and nickel. It consists of two parts—a liquid outer
core and a solid inner core. The outer core is a layer of molten metal surrounding the inner
core. The inner core is a dense ball of solid metal. Scientists think that movements in the liquid
outer core create Earth’s magnetic field.
Identify Supporting Evidence
How can iron filings provide evidence that the bar magnet has a magnetic field?
Materials
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Ziploc® bags
3 x 5-inch index card
Teaspoon of iron filings
Paper clip
Bar magnet
Procedure
1. Take a Ziploc® bag and place a 3 x 5-inch index card underneath. Add about 1/2 teaspoon of
iron filings. Be careful to keep your magnet away from the filings. They will stick to it and are
hard to get off!
2. Lay the plastic bag on a table and shake it gently back and forth. Let your partner try it, too.
With a little practice, you can get a thin layer of filings on top of the index card in your bag. The
filings should not all be in a lump at one end.
3. Carefully lift the bag and set it on a paper clip. Describe what happens and draw it in the
space below.
Drawing
4. Can you predict what will happen to the iron filings if you place a magnet on the table and set
the bag down on top of the magnet? Write your prediction below.
5. Now place the magnet on the table. Then gently pick up the bag and place it on the magnet.
What happens? Was your prediction correct? Draw what you see in the space below:
6. Now, put your two bar magnets end-to-end so that they are attracted to each other and
then put your zipper-lock bag on top. What do the magnetic fields of the two magnets look like
now? Draw a picture on your data sheet.
7. Next, put your two magnets end-to-end so that they repel each other. Set your zipper-lock
bag on top and see if the fields look different. Draw a picture on your data sheet of what you
see.
8. Look at your pictures. Can one magnetic field change the shape of another magnetic field
when they get close to each other? If so describe.
What do your drawings show you about this?
Homework
Research the Earth’s magnetic field on line. Draw a picture of the planet Earth and its magnetic
field. Doesn’t need to be too complex. Answer this question – What causes the Earth’s
magnetic field, and how does it protect us?
Earth’s magnetic field