Download D38 Beneath Earth*s Surface

D38 Beneath Earth’s Surface
D38 Background
• When volcanoes erupt, magma is released.
• Where does this magma come from?
• CHALLENGE QUESTION:
• What is beneath the Earth’s surface?
D38 Glass Elevator
• Imagine you are in a glass elevator traveling to
the center of the Earth.
• Draw a circle with a dot in the middle to
represent the Earth and its center.
• Now draw, label, and color everything you “see”,
putting them at their necessary depth.
• Write the distance you believe it is to the center
of the Earth in kilometers (km).
• Put an “X” where you think nuclear waste should
be stored, and label that depth in km.
D38 On Earth’s Surface: Reading 1
• A Volcano is an opening in the Earth where
magma and gas erupt. Gases in the magma
build up pressure to force it up and through
gaps in the Earth’s surface, causing eruption.
• Lava: magma (melted rock) that erupted
• Lava cools and forms volcanic rock. Over time
volcanic rock and ash can form a mountain or
hill around the opening, called a volcano.
D38 On Earth’s Surface: Reading 2
• Volcanic eruptions are not all alike. Some are
gentle with lava slowly seeping from a vent.
• Other eruptions are violent with lava, ash, and
other materials thrown high into the air.
• Eruptions cause different volcanic mountain
shapes such as composite, cinder, and shield.
D38 On Earth’s Surface: Reading 3
• There is a lot of evidence of Earth volcanoes.
• Many mountains have been formed from the
volcanoes that are extinct or dormant.
• Yucca Mountain was formed from volcanic
material exploding from a composite volcano
that is now extinct. The 7 dormant volcanoes
near Yucca Mountain are cinder cones.
D38 Composite Volcano
• These have explosive eruptions caused by
more gassy magma.
• They are formed from layers of lava and ash.
D38 Cinder Cone Volcanoes
• These are the smallest and most common.
• They form from explosive eruptions shooting
small pieces of magma and ash into the air.
• The magma then cools and hardens as it falls
back to the Earth, forming a cinder cone.
• Often cinder cones form on the sides of larger
volcanoes.
D38 Shield Volcanoes
• These usually form large, broad volcanoes.
• They release fast-moving, less gassy lava and
have less explosive eruptions than other types.
• People can often walk fairly close to these
erupting volcanoes.
D38 Inside Earth: Earthquakes 1
• Early evidence about the inside of the Earth
came from volcanic eruptions. Recently the
learning is from newer technology & methods.
• Scientists have also learned from earthquakes.
• Earthquake waves move through materials in
different ways and at different speeds. They
move faster through more dense solids and
slower through less dense solids. The waves
move slowest through liquids.
D38 Inside Earth: Earthquakes 2
• Scientists measure an earthquake’s waves at
different places on Earth’s surface.
• By analyzing and comparing the data from
many earthquakes, they have been able to
determine the state (solid, liquid, or gas) of
the material inside the Earth.
D38 Inside Earth: Earth Layers 1
• We now know that rocks on the surface are
only a tiny fraction of what makes the planet.
• Think of Earth as an egg. The thickness of the
eggshell would represent the thickness of all
the rocks at the surface.
• Beneath an eggshell is egg white and yolk.
D38 Inside Earth: Earth Layers 2
• What is beneath the rocks of Earth’s surface?
• Earth has 3 layers: Crust, Mantle, and Core.
• The core is made up of both a solid layer (the
inner core) and liquid layer (outer core).
D38 Inside Earth: Layers 3
• Magma often comes from the mantle layer. It
collects underground and builds up pressure
before exploding toward the surface.
• The mantle is almost 3000 km thick, similar to
the distance from New York City to Denver, CO
• The mantle top is more solid than the bottom.
• Lithosphere: combination of the solid crust &
upper mantle down to 100 km below surface.
LAYERS OF THE EARTH
CRUST
MANTLE
DEPTH BELOW
SURFACE (km)
STATE
MATERIAL
TEMP (C)
0-40
solid
Many kinds of rocks
0-700
upper solid,
lower liquid
Magnesium, iron,
and silicon
700-2800
40-2800
OUTER
CORE
2800-5200
liquid
Iron and nickel
2800-5200
INNER
CORE
5200-6400
solid
Iron and nickel
Over 6000
D38 Talking Drawing 1a
Get a Talking Drawing 1 worksheet:
1. Record distance to the center of the Earth.
2. Record distance from Earth’s surface to its
center on the drawing (in centimeters).
3. How many km=1cm? This is called a scale.
4. Record lowest depth of each Earth layer (km).
5. Use your scale and a calculator to determine
the scaled depth of each Earth layer (cm).
D38 Talking Drawing 1b
6. Use rulers to measure the depth of each layer
starting from Earth’s surface. Draw a circle at
each depth but do the crust location last.
7. Label each layer with name, state, and temp.
8. Label lithosphere and record its depth in km.
9. Nuclear waste is often stored at a depth of
about 0.3 km (300 meters or 1000 feet). Put an
“X” on that layer of your drawing.
10. Compare this drawing with your first one.
D38 Beneath Earth Analysis: Date____
Name____________________ Hour__
• Copy and Explain using 1 paragraph each:
1. Which layer(s) of the Earth is (or are):
a. hottest b. at Earth’s center c. completely solid
1. Copy these five words or phrases:
outer core, mantle, lithosphere, solid, crust
a. Cross out the word (phrase) that does not belong.
b. Circle the word that includes all the other words.
c. Explain how the word circled relates to the others.