Transcript Layers of the Earth PPT

INSIDE THE EARTH
Plate Tectonics
The Composition of the Earth
A. These layers describe the chemical makeup of the
Earth, the compounds found in the layers
B. Crust – thinnest, outermost layer
- Made of oxygen, silicon, and aluminum
1. Oceanic – more dense than continental crust
2. Continental – thicker than oceanic crust
C. Mantle – middle layer (thicker than crust)
- Has more magnesium, so it is more dense than
crust
D. Core – inner layer (most dense layer)
- Made mostly of iron and some nickel
Facts about the layers
• The crust can be as thick as 3 miles to 75 miles in size.
• No one has ever been below or even drilled below the
crust.
• The center of the Earth is hotter than the surface of the
Sun.
• The temperatures in the mantle range from 2000-5000 ºF
• The temperatures in the core range from 7000-12000 ºF
• The core creates the Earth’s magnetic field
Physical Structures
We think of the Earth as having three layers;
crust, mantle and core. The Earth layers
are also described in a different way.
The five physical layers include:
1. Lithosphere 2. Asthenosphere
3. Mesosphere 4. Outer core
5. Inner Core
1. Lithosphere
A. Consists of the crust and top part of
mantle
• Outermost, rigid layer
B. Made of solid rock/minerals
C. Pieces of the lithosphere are divided
into tectonic plates
• Can contain both continental and
oceanic crust
• Lithos is Greek for “rock”
2. Asthenosphere
A. Under the Lithosphere
B. Part of the mantle
C. Made of bendable rock
1. Like a marshmallow
2. Still a solid but it can move and flow
D. Astheno is Greek for “weak”
3. Mesosphere
A. Below the Asthenosphere
B. Lower part of the mantle
1. Touches the outer core
C. Made of hard strong solid
rock/minerals
D. Meso is Greek for “middle”
4. Outer Core
– hot, liquid layer that is between the
mesosphere and the inner core
5. Inner Core
– center of the Earth
– solid, metal ball
– most dense layer
Mapping the Earth’s Interior
•Earthquakes give us clues to what is below the crust
•Seismic waves are vibrations given off when there is an
earthquake
•They travel at different speeds depending on the
composition
• Waves travel faster through a solid than a liquid
• S waves cannot travel through liquids
• P waves can travel through solids and liquids
• Seismographs are instruments that measure the time it
takes for seismic waves to reach a site
Layer of
Earth
Physical layer What they are like
Lithosphere
Asthenosphere
Mesosphere
Outer Core
Inner Core
Fill in the chart using the
following…
• Core
• Mantle
• Core
• Mantle
• Crust
• Mantle
• Thought to be solid
rock, found in middle
• Solid and very rigid
(eroded/weathered
rock)
• Pure liquid, very hot
• Solid and dense
metal ball in center
of Earth
• Hot and soft rock
that flows
(marshmallow)
Layer of Physical layer
Earth
Crust
What they are like
Lithosphere
Solid and very rigid rock
(eroded/weathered rock)
Mantle Mesosphere
Thought to be solid rock,
found in middle
Core
Outer Core
Pure liquid, very hot
Core
Inner Core
Solid and dense metal ball
in center of the Earth
Mantle
Mantle Asthenosphere Hot and soft rock that
flows slowly