Download Chapter 7 Section 1

Chapter 7 Section 1
Inside the Earth - Pages 190-193
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Layers of the Earth
Brown
Blue
A. Composition of the Earth
1. The Earth is divided into 3
layers:
-Crust
-Mantle
-Core
2. The Crust and Mantle are made of less
dense compound.
3. The Core is more dense than the crust
and mantle.
B. CRUST
1.
2.
3.
4.
5.
The outermost layer
5-100 km thick
Thinnest layer
2 types of crust:
Continental (land)- thick and Oceanic (under
the ocean)-thin
C. MANTLE
1.
2.
3.
4.
5.
6.
Mantle
2900 km thick
Between the crust and core
Thick
Contains most of Earth’s mass
Scientists study the mantle by looking at the
composition of magma.
Magma from volcanoes gives scientists clues
about the composition of the mantle.
D. CORE
1.
2.
3.
4.
Innermost layer
Made mostly of iron and nickel
Inner core solid
Outer core liquid
Core
E. Physical Properties of Earth
1.
Lithosphere
2.
Asthenosphere
3.
Mesosphere
4.
Outer Core
5.
Inner Core
F. Lithosphere
1.
2.
3.
Outermost layer of Earth
Made of crust and upper mantle
Divided into pieces called tectonic plates.
What are tectonic plates?
1. The Earth’s lithosphere, crust and upper
mantle ,are divided into pieces called tectonic
plates.
2. Think of the lithosphere like a jigsaw puzzle.
3. Each of the plates is a piece of the puzzle.
4. These plates move causing earthquakes,
mountain building, seafloor spreading and
volcanoes.
Tectonic Plates
G. Asthenosphere
1.
2.
3.
4.
Layer below Lithosphere
Pieces of lithosphere (tectonic plates) move
along this layer.
Made of solid rock, soft layer of the mantle
Solid that acts like a
liquid due to pressure
and temperature.
Why is the asthenosphere
considered “plastic”?

Because it is very hot, and made of partially
molten rock, it bends and can be pushed and
deformed due to the pressure placed on it
from deep within the Earth.
H. Mesosphere
1.
2.
3.
Below the asthenosphere
Strong lower part of mantle
Extends to the Earth’s core
I. Outer Core
1.
2.
Liquid layer of Earth’s core
Surrounds inner core
J. Inner Core
1.
Solid dense center
Convection Currents


Cause plates to move
very hot material in
the mantle rising,
then cooling, sinking
again and then
heating, rising and
repeating the cycle
over and over.
Earth’s Magnetic Field

Magnets are simple examples of natural magnetic fields.
Believe it or not, the Earth has a huge magnetic field.
Because the core of our planet is filled with molten iron (Fe),
there is a large field that protects the Earth from space
radiation and particles such as the solar wind. When you
look at tiny magnets, they are working in a similar way. The
magnet has a field around it.
Earth’s Magnetic Field- Protection
from Solar Radiation
Earth’s Magnetic Field- North and
South Poles
As mentioned earlier, the Earth is like
a giant magnet because of its large
iron content. It has a north pole and
a south pole. This giant magnet is
what makes a compass work. No
matter where you turn it, the needle
of a compass will ALWAYS point to
the north.
https://www.youtube.com/watch?v=lxWBlJ1k
B7Q
Quiz
1. Name the three main layers of the Earth.
2. Which layer is the most dense?
3. Which layer is the thinnest?
4. What are the two types of crust?
5. Which layer contains most of Earth’s mass?
6. What two layers make up the lithosphere?
7. The lithosphere is divided into pieces called:
8. Pieces of lithosphere move on top of this layer:
9. The Asthenosphere is said to be “plastic”. What does this
mean?
10. Which layer, inner core or outer core, is liquid?
11. Which layer, the inner core or the outer core, is solid?
Answers
1.Crust, mantle and core
2. Core
3. Crust
4. Continental and oceanic
5. Mantle
6. Crust and upper mantle
7. Tectonic Plates
8. Asthenosphere
9. Because it is very hot and made of partially molten rock it bends and can be
pushed and deformed due to the pressure placed on it from deep within
the Earth.
10. Outer core
11. Inner core