Download 1. - Riverdale Middle School

pg. 69
• A system is a group of parts that work together as
a whole.
• The constant flow, or cycling, of matter through
the Earth system is driven by energy.
• Energy is the ability to do work.
• Energy that drives the Earth system has two main
sources:
1.) heat from the sun
2.) heat flowing out of Earth as it cools
Earth’s System Has 4 Main Spheres:
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1.) Atmosphere- Earth’s outermost layer made up of
a mixture of gases: mostly nitrogen and
oxygen. Contains dust, cloud droplets, water
vapor, rain, snow, earth’s weather
2.) Geosphere- the solid rocks and metals
that make up the Earth. Four parts: crust,
mantle, outer core, inner core
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3.) Hydrosphere- Contains all of Earth’s water. pg. 69
Water covers about ¾ of Earth’s surface.

97% is salt water

2% is frozen in the polar ice caps

1% is drinkable (fresh water)
4.) Biosphere- the parts of Earth that contain
living organisms
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pg. 68
Notes: Constructive Vs. Destructive Forces
Lands are constantly being created and destroyed by
competing forces.
Constructive Forces
Destructive Forces
Forces that destroy and wear away
Forces that construct and shape
landmasses.
the land’s surface by building up
mountains and other land masses.
Examples:
Examples:
Notes: Earth’s Layers
pg. 71
How do Geologists Learn About Earth’s Layers?
A. They use two main types of evidence to learn about Earth’s
interior:
1.) direct evidence from rock samples
a. Geologists have drilled holes as deep as 12.3 km into
Earth.
b. The drills bring up samples of rock. These rocks give
geologists clues about Earth’s structure and conditions
deep inside Earth.
2.) indirect evidence from seismic waves.
a. When earthquakes occur, they produce seismic waves .
b. Geologists record the seismic waves and study how they
travel through Earth.
What Are the Features of Earth’s Layers?
B. The three main layers of Earth are the crust, mantle and core.
1.) The layers vary greatly in size, composition, temperature,
and pressure.
2.) The deeper down inside Earth, the greater the pressure.
3.) The temperature inside earth increases as depth increases.
C. The Layers of the Earth
1.) Crust – a layer of solid rock that includes both dry land and
the ocean floor (Earth’s outer skin)
a. Oceanic Crust – the crust that lies beneath the ocean;
mostly composed of basalt (a dark, fine-grained rock)
b. Continental Crust – the crust that forms the continents;
mostly composed of granite (a rock that is usually light in
color and has coarse grains)
2.) Mantle – a layer of rock that is solid, and very hot
a. Lithosphere – made up of the crust and upper mantle;
strong, hard and rigid rock
b. Asthenosphere – below the lithosphere; the material is
hotter and under more pressure; the material can bend
but is still considered a solid
3.) Core – below the mantle; made mostly of the metals iron a
nickel; consists of 2 parts
a. Outer Core – molten/liquid metals of iron and nickel
b. Inner Core – dense ball of solid metals iron and nickel
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1. Continental Crust
2. Oceanic Crust
6. Lithosphere
7. Asthenosphere
3. Mantle
4. Outer Core
5. Inner Core
Pg. 70
Draw and Label the Layers of the Earth
Crust
Lithosphere
Asthenosphere
Mantle
Outer Core
Inner Core
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1.) RADIATION –
:
2.) CONDUCTION –
:
3.) CONVECTION –
:
• Heat from the core and the mantle itself causes convection currents
in the mantle.
• Mantle rock rises slowly from the bottom of the mantle toward the
top. The hot rock eventually cools and sinks back through the
mantle. Over and over the cycle of rising and sinking takes place.
• Convection currents like these have been moving inside Earth for
more than four billion years!