2. Planet Earth…2012
Earth is our planet, our home. Have you
ever wonder what lies beneath your feet?
Well, let´s take a fantastic look at it!
3. Compositional Layers
To study the layers of
Earth, scientists make
2 classifications of
them. Compositional
and Physical Layers.
They are related to
each other.
In this picture we can see the Compositional layers.
They include: The Crust, the Mantle, and the Core.
4. Compositional Layers
Crust: It is the layer we live on. It
includes all the continents and
even the ocean floor! The crust is
made up of 3 elements: oxygen,
silicate and aluminum.
Mantle: It is the middle of Earth´s
compositional layers. Some of
the rock in the mantle is like wax
that is soft but not completely
melted.
Core: Innermost part of Earth.
Made up mostly of 2 elements:
iron and nickel which are metals.
5. Physical Layers
There are 5 Physical Layers. They
are determined by their physical
properties, such as if a layer is
hard or soft, solid or liquid.
The Lithosphere is the uppermost
layer of Earth. It is almost all
solid. It is directly related to the
Crust and a little part of the
Mantle. It is divided into pieces
called Tectonic Plates.
6. Physical Layers
Next come the Asthenosphere and the Mesosphere. Both are
related to the Mantle. The tectonic plates float on the
Asthenosphere, which is soft. Rock in the Mesosphere is softer
than rock in the Asthenosphere.
7. Physical Layers
The innermost physical layers are
the Outer Core and the Inner
Core. In this picture, they are
represented by the red and the
yellow part. Both are related to the
Core. They are divided because
the Outer Core is liquid and the
Inner Core is solid. They are made
mostly of iron and nickel.
The reason why the Inner Core is a
solid ball of iron is because of the
pressure of all the other layers
over it. But that doesnt mean is
cold. Some scientist compare its
heat to the temperature at the
Sun´s surface!
