Sciecne 10 – 1st
Quarter
LAYERS OF THE EARTH
PLATE BOUNDERIES
LAYERS OF THE EARTH
01
02
03
CRUST
MANTLE
CORE
- Continental
Crust
- Oceanic Crust
- Lithosphere
- Asthenosphere
- Outer Core
- Inner Core
01
CRUST
THE CRUST
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The Earth’s crust is the outermost surface.
It is a very thin layer of solid rock. It is the thinnest layer of the
Earth.
The crust is 5-35km thick beneath the land and 1-8km thick
beneath the oceans.
The crust of the Earth is broken into many pieces called plates.
The Lithosphere
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The word lithosphere is derived from the word “sphere,”
combined with the Greek word “lithos” which means rock.
The lithosphere, sometimes called the geosphere, refers to all
of the rocks of the earth.
The boulders of Mount Everest, the sand of Miami Beach and
the lava erupting from Hawaii's Mount Kilauea are all
components of the lithosphere.
The Lithosphere
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The outermost and most rigid mechanical layer of the Earth.
The lithosphere is composed of part of the crust and the upper
part of the mantle (the top 100 km).
The average thickness is ~70km, but ranges widely: It can be
very thin, only a few km thick under oceanic crust or midocean ridges, or very thick, 150+ km under continental crust,
particularly mountain belts.
02
MANTLE
THE MANTLE
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The mantle is the largest layer of the Earth. It is 2900km
thick.
It includes the lithosphere and asthenosphere.
The mantle is not liquid. It is, however, ductile, or plastic,
which means that on very long time scales and under
pressure it can flow.
ASTHENOSPHERE
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The asthenosphere is underneath the lithosphere. It is
about 100km thick, and is a region of the mantle that flows
relatively easily. Reminder: it is not liquid
It is made of molten rock and metal so that it “flows” like hot
asphalt.
*The asthenosphere is the part of the mantle that moves
and causes the tectonic plates of the crust to move as well
CONVECTION CURRENT
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Convection currents are caused by the very
hot material at the deepest part of the
mantle rising being less dense, then
cooling becoming more dense and sinking
again --repeating this cycle over and over.
03
CORE
THE OUTER CORE
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Composition: Molten (liquid) metal that is about
4,700°C (8,500°F)
Thickness: 2,266 km (1,400) miles
State of Matter: Composed of the melted metals nickel
and iron (liquid)
Located about 1,800 miles beneath the crust.
THE INNER CORE
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Solid sphere made mostly of iron and has Nickel
It is believed to be as hot as 6,650°C (12,000°F)
Heat in the core generated by the radioactive decay of
uranium and other elements
It is solid because of the pressure from the outer core,
mantle, and crust compressing it.
Thickness: 1271 km (800 miles)
What do these images tell us about the layers
of the Earth?
Look at the information in the graph and table below. What’s
the relationship between depth and density/pressure?
LAYERS OF THE EARTH
In a sheet of paper draw the layers of the Earth.
Include the following parts.
- Crust
- Inner Core
- Continental Crust
- Outer Core
- Oceanic Crust
- Lithosphere
- Asthenosphere
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