1. Self Starter 2/18
Use the book to write the definitions of asthenosphere and lithosphere.

2. Today’s Goal: I can name and explain the layers of the Earth
CFA THURSDAY OVER LAYERS OF EARTH

3. Today’s Plan:
10 minutes to finish Earth’s Layers Foldable Question sheet
If you finish early or are done, read pages
Notes & Review layers of Earth
Convection

4. Layers of the Earth Crust: Composition: O, Si, Al Thickness: 5-100 km
State of Matter: Solid
Outer Core:
Composition: Fe & Ni
Thickness: 2200 km
State of Matter: Liquid
Mantle:
Composition: Mg, Si
Thickness: 2900 km
State of Matter: Solid & Liquid
Inner Core:
Composition: Fe & Ni
Thickness: 1230 km
State of Matter: Solid

5. Crust The crust is the OUTER MOST layer of the Earth.
On Continents the crust is between km thick, and at the bottom of the ocean the crust is 5-10 km thick.
The crust is made mostly of silicates (hard, metal-based rocks).
The crust is SOLID

6. Mantle Thickest layer of the Earth. Nearly 2900 km thick!
The mantle is where most of the Earth’s internal heat is contained.
The heat from the mantle moves tectonic plates.
The mantle is made of semi-solid silicates (imagine plastic-ish rocks that can be bent and molded, but are still very strong).
The mantle is kind of liquid, kind of solid

7. Core Outer Core: 2300 km thick and made of liquid iron, and nickel
It is hypothesized the Earth’s magnetic field is controlled by the outer core.
Inner Core: 1200 km thick and made of solid iron.
The inner core is about 6000⁰ C

8. How the Earth is Separated:
These layers of the Earth are based on COMPOSITION: what materials they are made of.
But in this class we also talk about layers of the Earth that are based on MECHANICAL PROPERTIES: or how the layers interact with each other.

9. Composition and Mechanical Properties

10. Lithosphere (rigid solid)
Asthenosphere (capable of flow)

11. Mechanical Properties
Lithosphere = includes the crust and upper, solid part of the mantle.
Asthenosphere = semi-liquid part of the earth including the mantle and outer core.
The lithosphere floats on top of the asthenosphere, making plate movement possible.

12. Astheno – from asthenia - means weakness
Litho – from lithos – means stone

13. Back to Crust The crust is broken into large chunks that move together
These chunks are called tectonic plates

15. Practice
Lithosphere
Solid
Asthenosphere
Liquid
Solid-Liquid
Solid