Transcript Journey to the Center of Earth

Journey to the
Center of Earth
Layers of the Earth
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Crust
Lithosphere
Asthenosphere
Mantle
Outer Core
Inner Core
Crust
• This is the layer that we live on
• The thickness ranges from five miles
under the oceans to 25 miles under the
continents
• Consists of cooled rock- granite and
basalt
• It is the thinnest layer of the earth
Lithosphere
• Floats on the asthenosphere and includes
all of the crust and part of upper mantle
• Cool solid portion of the Earth
Asthenosphere
• A zone of partially melted rock in the upper
mantle
The Mantle
• This layer is semiliquid
• It consists of
magnesium, iron,
and silicon
• It is 3000 km wide
• It is more solid closer
to the surface
The Outer Core
• This consists of liquid due to the high
temperatures
• It is 2100 km wide
• This layer consists of nickel and iron
The Inner Core
• This layer is solid.
• The reason it is solid is due to the high
pressure exerted on it from the outside
layers.
• It consists of the metals nickel and iron.
• Its temperature is 6,000 C.
• Its width is 2,100 km.
Earth’s interior layers.
• The major layers of the
Earth consist of the crust,
lithosphere,
asthenosphere, mantle,
outer core and inner core.
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.
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.