Transcript 3 Biology and Geology 3. Secondary Education

UNIT
7
Energy changes the Earth
THE LAYERS OF THE EARTH
Biology and Geology 3. Secondary Education
UNIT
UNIT
7
3
The layers of the Earth
The Earth is composed of a series of layers, as shown in the illustration.
Geosphere
Biosphere
Atmosphere
Hydrosphere
To know more about them,
click on each one.
Biology and Geology 3. Secondary Education
UNIT
UNIT
7
3
The layers of the Earth
The geosphere
• The geosphere is composed of the crust, the mantle and the core.
The core is the innermost layer of
the planet. Its density is high
because it is composed of metals.
The mantle is an intermediate layer
beneath the crust. It is composed of
rocks which are slightly denser than
those of the crust.
The crust is the outermost
solid layer of the Earth. It is
composed of rocks of low
density.
Biology and Geology 3. Secondary Education
UNIT
UNIT
7
3
The layers of the Earth
The Earth is composed of a series of layers, as shown in the illustration.
Geosphere
Biosphere
Atmosphere
Hydrosphere
To know more about them,
click on each one.
Biology and Geology 3. Secondary Education
UNIT
UNIT
7
3
The layers of the Earth
The hydrosphere
The hydrosphere is composed of all the water on Earth: the oceans, the seas, the ice in
the glaciers, the lakes, the rivers, the streams, etc. This layer covers three quarters of the
Earth’s surface.
Biology and Geology 3. Secondary Education
UNIT
UNIT
7
3
The layers of the Earth
The Earth is composed of a series of layers, as shown in the illustration.
Geosphere
Biosphere
Atmosphere
Hydrosphere
To know more about them,
click on each one.
Biology and Geology 3. Secondary Education
UNIT
UNIT
7
3
The layers of the Earth
The atmosphere
The atmosphere is the outermost and the lightest layer of the Earth. It is composed of all the
gases that make up the air (78% nitrogen, 21% oxygen and small amounts of other gases, such
as carbon dioxide and water vapour).
Biology and Geology 3. Secondary Education
UNIT
UNIT
7
3
The layers of the Earth
The Earth is composed of a series of layers, as shown in the illustration.
Geosphere
Biosphere
Atmosphere
Hydrosphere
To know more about them,
click on each one.
Biology and Geology 3. Secondary Education
UNIT
UNIT
7
3
The layers of the Earth
The biosphere
The biosphere is composed of all the living things that inhabit the layers of the
Earth: the fish, the algae, etc., which live in the hydrosphere; the birds, the insects,
etc., in the atmosphere; and the mammals, reptiles, spiders, plants, etc., which are
on and in the crust of the geosphere.
Biology and Geology 3. Secondary Education
UNIT
UNIT
7
3
The layers of the Earth
The Earth is composed of a series of layers, as shown in the illustration.
Geosphere
Biosphere
Atmosphere
Hydrosphere
To know more about them,
click on each one.
Biology and Geology 3. Secondary Education