Earth and Space Science / Unit 3: Plate Tectonics
3.2 Earth's Layers by Physical Properties
Notes
Layers can also be described by how they behave.
- Lithosphere: rigid outer shell (crust plus the uppermost mantle), broken into plates.
- Asthenosphere: hot, weak, slowly flowing part of the upper mantle on which plates move.
- Mesosphere (lower mantle): stronger, solid rock under high pressure.
- Outer core: liquid. Inner core: solid because of enormous pressure, even though it is very hot.
- Movement of the liquid outer core generates Earth's magnetic field.
Practice
Which layer is liquid?
The liquid outer core generates the magnetic field.
Tectonic plates are pieces of the:
The lithosphere is rigid and broken into plates.
Why is the inner core solid even though it is hotter than the outer core?
Pressure raises the melting point.
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