Lesson 6 in Erath and Life science- Layers of the Earth.

The layers of the Earth are divided into four main parts, each with unique properties and compositions:atmosphere,biosphere, geosphere and hydrosphere

1. •Objectives
•1. Identify the layers of
the Earth
•2. Differentiate the layers
of the Earth from each
other

2. LAYERS OF THE EARTH

5. CRUST
•Oceanic crust – more
dense than continental
crust due to differences in
their composition,
formation processes, and
the minerals they contain

6. •Oceanic crust is primarily
composed of basalt,
which is rich in iron (Fe)
and magnesium (Mg),
minerals that contribute to
its higher density.

7. •Oceanic crust forms at mid-
ocean ridges through volcanic
activity, where magma from the
Earth's mantle rapidly cools to
create basaltic crust.
•The rapid cooling produces
denser, more compact minerals.

8. •Oceanic crust is generally
younger than continental crust
because it is constantly being
recycled at subduction zones.
• As oceanic crust ages, it
becomes denser as it cools and
contracts,

9. •Continental
crust – thicker
than oceanic
crust

10. •Continental crust consists
mostly of granite, which
contains lighter minerals like
quartz and feldspar, rich in
silica (Si) and aluminum (Al),
making it less dense.

11. •Continental crust forms through
more complex processes including
volcanic activity, sedimentation, and
the gradual accretion of lighter
materials over time.
•Older and less recycled so it retains
its lighter composition.

14. CRUST
•

The crust is the outermost layer of the
earth.
•It is the layer we live on.
•-a solid layer made of rock
•-Mainly composed of oxygen, silicon, and
aluminum
•

15. •-the thinnest layer of the earth
•-around 30 kilometers thick
•- about 25 to 30 degrees Celsius
per kilometer
•-No one has ever been below or
even drilled below the crust.

16. MANTLE
•- the layer next to the crust
•- the thickest layer of the Earth
•-thick liquid layer made of molten rocks
•- sometimes called a plastic layer instead
of liquid
•- about 3000 km thick
•- 500-1400 degrees Celsius

17. •Has more magnesium, so it is
more dense than crust
•-the heat from the outer core
makes the part of the mantle
closest to the outer core
become hotter than the rest

18. •-the part of the mantle that is
hotter is lighter, so it floats to the
top and cools
•- after it has cooled it sinks again
because it is heavier
•-this makes currents in the mantle
that move the crust above it

19. OUTER CORE
•-the third layer of the earth
•-a liquid layer made of molten
Iron and Nickel
•-the Outer core is 2,266 km
thick
•-about 4000 degrees Celsius

20. INNER CORE
•- the innermost layer of the Earth
•-a solid layer made of nickel and iron
•- about 250-400 km thick
•- the hottest layer of the earth, around
5,700 degrees Celsius
•- hotter than the surface of the Sun

21. •The Inner Core is solid even though
it is the hottest layer of the earth
•It stays solid because there is so
much weight on it the little bits that
make it up have no room to move
•- the core creates the Earth’s
magnetic field