1. Which branch of Earth Science would study
earthquakes?
2. Which branch of Earth Science would study
hurricanes?
3. Which branch of Earth Science would study the
warming of the oceans’ waters?
4. Which branch of Earth Science would study
asteroids?
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What are the layers of the Earth?
What is the crust?
What are the characteristics of the Earth’s Crust?
What is the composition of the Earth’s Crust?
What is the lithosphere?
What is the Moho?
What is the mantle?
What are the characteristics of the Earth’s Mantle?
What is the composition of the Earth’s Mantle?
What is the asthenosphere?
What is the mesosphere?
What is the core?
What is the outer core?
What is the inner core?
• Crust
• Mantle
• Core – Outer Core
and Inner Core
• The crust is the outermost layer of the Earth
• Thickness: 5 to 100 kilometers thick
Continental Crust: ~ 30 km
Oceanic Crust: ~ 5 km
• Crust floats on the mantle.
• Crust is thin.
• Two layers – Top layer of granite and a more dense
bottom layer of basalt. Both layers are found
under continents, only the basalt layer is under the
oceans.
• Temperatures increase with depth: 20° C at top
and 870° C at bottom.
Crust is composed of:
• Oxygen: ~ 50%
• Silicon: ~ 30%
• Aluminum: ~ 10%
Crust Composition
10%
10%
Oxygen
50%
30%
Silicon
Aluminum
Other
Lithosphere:
• Made up of crust and uppermost layer of the
mantle.
• Approximately 80 km thick.
• Broken into pieces (tectonic plates) which move
around on the asthenosphere.
Moho:
• Boundary between the crust and the mantle that is
more dense than the crust.
• The mantle is the thickest part of the Earth.
• Thickness: ~ 2,900 km
• Upper and Lower Mantle – they differ in
temperature, density, and pressure. These
increase as depth increases.
• Temperatures: Top of mantle is ~ 870° C and bottom
is ~ 2,200° C.
• Rock begins to flow like very thick syrup as
temperature increases.
Composition:
• Silicon, Oxygen, Iron, and Magnesium
• The deeper the rocks are in the mantle,
the more iron they hold.
Asthenosphere:
• Upper part of the mantle.
• Found between 75 km and 200 km deep.
• Semiplastic layer which moves fluidly due to
convection currents.
Mesosphere:
• Layer of the mantle below the asthenosphere.
• 350 to 2,900 km deep.
• Great pressure - it is solid and more rigid than the
rock on top of it.
• Innermost layer of the Earth.
• Two layers – Outer Core and Inner Core
• Thickness: Outer Core is ~ 2,250 km thick and
Inner Core is ~ 2460 km in diameter.
Outer Core:
• A shell surrounding the inner core.
• Composed of liquid iron and nickel.
• Temperature: ~ 2,200° C at its outer surface
and ~ 5,000° C at its inner surface.
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Innermost layer of the Earth – Sphere.
Composed of solid iron and nickel.
Temperature: ~ 5,000° C.
Solid due to extreme pressure bearing down.