Warm up
Write the questions!!
1. Describe the interior (Underground) of the Earth.
2. About how deep is the Earth going from one end to
the other?
Use page 309-311
Describe the interior (Under
ground) of the Earth.
• The Earth is divided in to 4 main layers.
The Crust, Mantle, Outer Core, and Inner
Core
About how deep is the Earth
going from one end to the other?
• About 33, 600 Ft
• 4000 miles
Layers of the Earth
• Skin of the peach is
the crust
• Meat of the peach is
the mantle
• Pit of the peach is the
core
Layers of the EARTH
CRUST
5 to 25 miles thick
and up to 1,600 F
MANTLE
1,800 miles thick
and up to 8,000 F
INNER CORE
800 miles thick
and up to 13,000 F
OUTER CORE
1,400 miles thick
and up to 11,000 F
The Crust
• The thickness of Earth’s crust varies from about 32 kilometers
under the continents, to about 8 kilometers under the oceans.
• Earth’s crust is made of two layers. The top layer is made mostly
of light colored rock called granite, is less dense than the bottom
layer which is made up of a dark colored rock called basalt.
• Both layers are found under the Earth’s continents. Only basalt is
found in the crust under the oceans.
• Temperatures increase with depth from about 20 degrees C. at the
top and a sizzling 870 degrees C. at the bottom of the crust.
The Mantle
• About 100 years ago a Croation scientist Andrijal
Mohorovicic made a discovery while studying the behavior of
earthquakes in the ground. His studies Revealed that the
waves increased in speed as they passed through a boundary
at a depth below the surface between 32 and 64 kilometers.
He felt that this happened because the waves traveled through
a less dense area.
• We now know that he founded the layer next to Earth’s crust
which was the mantle.
• The makeup of the mantle’s rock is similar to the crust’s. The
main difference is that there is more iron in the mantle than in
the crust.
• Earth’s Mantle is about 2,900 kilometers thick and
Temperature range from about 870 degrees C. to 2,200
degrees C at its bottom. At these temperatures rock begins to
flow like a thick syrup.
The Outer & Inner Core
• Earth’s made up of two parts, a shell called the outer core and a sphere
called the inner core.
• The outer core temperature ranges from 2,200 to 5000 degrees C. which
is the temperature of the inner core.
• Both cores are made up of iron and nickel.
• However, while the iron and nickel in the outer core are liquids, the same
metals in the inner core are solids.
• The melting point of iron is 1535 degrees C. The melting point of nickel
is 1455 degrees C. Since the temperatures are higher than the melting
points in both cores you might expect it to be liquid in both places.
• BUT the reason that the inner core is solid is do to the enormous pressure
bearing down on the inner core. This is the Pressure of the Crust, Mantle
and Outer Core COMBINED! Pressure can keep a solid from expanding
even when the temperature is greater than the melting point.
• The outer core is about 2250 kilometers thick. The border from the inner
core to the center of Earth is about 1,230 kilometers thick
Questions?
1. In general, how does the density of material in the Earth’s layers
change with the depth?
a. Density increases with depth
b. Density decreases with depth
c. Density does not change with depth
d. Density increases, then decreases with depth
2. In Earth’s crust, what type of rock is found under the oceans?
a. only granite
b. Only basalt
c. Granite on top, basalt underneath
d. Basalt on top, granite underneath
3. The thickest layer of the Earth is the
a. Crust
b. Mantle
c. Inner Core
d. Outer core