Transcript Journey to the Center of Earth Layers of the Earth

Journey to the
Center of Earth
Layers of the Earth
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Crust
Lithosphere
Asthenosphere
Mantle
Outer Core
Inner Core
Crust
• Ranges from 5 – 100 km thick
• Continental crust: dense silicate
materials – solid and rocky outer layer
**Silicon, Oxygen & Aluminum**
• Oceanic crust: thin and denser minerals
The Mantle
• It is 2,900 km thick
• It made of Silicon,
Oxygen, and Magnesium
(more dense)
• Temperature ranges
from 870°C to 2,200°C
The Outer Core
• It is 2,250 km thick
• Made of MOLTEN iron and nickel  LIQUID
• Temperature ranges 2,200°C to 5,000°C
The Inner Core
• It is 1,200 km thick
• Made of SOLID Iron and Nickel
• Temperature ranges from 5,000°C or higher
• The reason it is solid is due to the high
pressure exerted on it from the outside
layers.
THE CRUSTAL SURFACE.
• CONTINENTAL CRUST – i
is between 20 and 60 km thick. It is
composed of granitic rocks, which
are less dense than basaltic rocks of
the oceanic crust. So, most of
continental crust is above sea level.
• OCEANIC CRUST is only about 10 km thick. It is
composed of basaltic rocks, which
are more dense than granitic rocks
of the continental crust. So, oceanic
crust is below sea level.
Earth’s interior layers.
• The major layers of the
Earth consist of the crust,
lithosphere,
asthenosphere, mantle,
outer core and inner core.
Composition of the Earth.
40%
iron
oxygen
30%
20%
10%
0%
silicon magnesium
the other
THE THEORY OF PLATE TECTONICS
• The framework explains how
and why the surface of the earth
constantly changes is called
theory of plate tectonic.
• The theory states that the
earth’s outer shell, the
lithosphere is divided into eight
large plates.
• Because each plate moves as a
single unit, the interiors of the
plates are generally stable. All
major activity such as
earthquake or volcano occur
along the plate boundaries.
Convection Currents
• Middle Mantle (Asthenosphere) is composed
of hot, dense rock that thickly flows.
• This movement is the reason Earth’s crustal
plates move in the Lithosphere.
• Convection Currents are caused by hot
material, deep in the mantle, rising then
cooling and sinking again