The structure of the earth
Layers
Objective: Students will understand the layers of the Earth (crust,
mantle, outer core, inner core), their characteristics, and how they
interact to shape geological processes.
Key Concept:
Crust, Mantle, Outer core, Inner core, Lithosphere, Tectonic
plates Seismic waves
ATL (Approaches to Learning) Skill:
Research Skills – Students will gather, organize, and interpret
information from different sources to explain the composition and
function of Earth’s layers.
The structure of the earth Layers
The Earth is unlike every other
planet in the Solar System in a
number of different ways.
It is the only planet that has liquid
water on its surface.
By using a variety of advanced
techniques, scientists have been
able to discover what lies beneath
the surface of our planet.
https://www.youtube.com/watch?v= There are five layers – the crust,
TXHjvOeK144 the upper mantle, the mantle, the
outer core, and the inner core.
The
Crust
The crust is the top layer that we
This is because
live on. The crustthe crust
looks is not
different
The crust is, on average, about
one continuous
in different piece,
places, someit isareas
made
22 miles thick. The thickest part is
up
haveof mountains,
pieces that overlap
oceans, to cover
lakes
thought to be about 40 miles
the
andentire planet.don’t.
hills, others
thick, and the thinnest is only 3
miles thick (that part is at the
These
The way pieces are called
the crust tectonic
is put together
bottom of the ocean).
plates.
is the reason that we have all of
these different formations.
Earth is
Fragile
These tectonic plates float on a
rocky mantle – the layer between
the surface of the Earth, its crust,
and its hot liquid core.
The inside of the Earth is active
and therefore earthquakes and
volcanoes can be caused by
these tectonic plates moving.
Over a long period of time the
movement of these plates
also forms mountains.
The
Mantle
The upper mantle mixes and moves, causing pressure underneath the
Thetemperature
Its mantle (upper
ranges
and from
lower500
together)
degreesaccounts
Celsiusfor
(500°C)
60% ofatthe
the crust
crust. This pressure can sometimes cause the mantle to leak out onto
Earth's
to 4,000°C
mass,
near
making
the outer
it thecore.
thickest layer of the Earth.
the surface of the Earth - a volcano!
The Outer
Core
The outer core is about 30% of
the Earth's mass. Its temperature
ranges from 4440°C to 6100°C
(which is as hot as the Sun!)
The outer core is a super-heated
liquid made of iron and nickel.
Without the outer core, life on
Earth would be very different.
Scientists believe that it is the
convection of liquid metals in the
outer core that create the Earth’s
magnetic field.
The Inner
Core
The inner core is made up of the
same metals as the outer core
(iron and nickel) but, instead of
being liquid, it is a solid. The inner
core reaches temperatures of up
to 5,500°C.
With its immense heat energy, the
inner core is like the engine room
of the Earth.
It is basically a solid ball with a
radius of about 760 miles (about
70% of the size of the Moon).
What Have You
Learnt?
Take this quick quiz to see how much you have remembered about
the Earth’s surface.
How many layers does the What is created when the mantle
1 Earth have? 6 leaks out onto the surface?
What two metals is the core
2 Name the layers. 7 made of?
What are the pieces of the Is the outer core a solid or a
3 Earth’s crust called? 8 liquid?
4 What causes earthquakes? 9 What is the inner core like?
Draw an annotated diagram
Which is the thickest layer of
5 the Earth?
10 showing the different layers of
the Earth.
