1. Earth’s Layers

2. WARM-UP Exploring Earth’s Interior (Article)
1. How did the author use the following as analogies in the reading? Pick TWO and briefly explain (use the article for help if you do not remember)
Ford cars & World Series
Brick traveling 45 minutes
An apple’s skin
Sidewalk in New York city & strand of spaghetti
2. How do we know the different layers exist?

3. Earth’s Layers (Article)
Exploring Earth’s Interior (Article)
What were the THREE main points of this part of the reading.
Earth’s Layers (Article)
Provide at least TWO facts about each layer of the Earth.
What is the lithosphere & asthenosphere?

4. WARM-UP
1. How do you think pressure and temperature change as you move closer to the center of the Earth? Why?

5. Inside the Earth Earth’s layers  Divided 2 different ways:
Composition (What it’s made of)
Physical Structure (Ex: solid or liquid)

6. Composition of the Earth
Three layers based on composition: 1) 2) 3)
Crust
Note: Denser material collects in the core because denser objects always sink due to gravity.
Mantle
Core

7. The Core Makes up 33% of the Earth’s mass
Mostly Fe with some Ni (the denser elements)
Little to No: O, Si, Al & Mg

8. The Mantle Between the core and crust
Contains most of the Earth’s mass (67%)
Mostly Mg & Fe with some Si, O, & Al (more Mg than Al, because Mg is more dense)
Temperature = 870oC – 2200oC
Composition studied from volcanic eruptions

9. The Crust Continental Crust Oceanic Crust Continental Crust
Thin & solid, outer most layer (5 – 100 km thick)
up to 870oC (increasing with depth)
Continental Crust
Oceanic Crust
Continental Crust
Oceanic crust 
Often composed of granite; mostly Si, O, Al, Ca, Na, K; thick & less dense
Usually composed of basalt; mostly Si, O, Fe, Mg; thin & more dense
Why does oceanic crust sit lower than continental crust?
- Basalt is more dense than rocks in continental crust.

10. Physical Structure of the Earth
Five layers based on physical properties: 1) 2) 3) 4) 5) 1
Lithosphere
Asthenosphere 2
Mesosphere 3
Outer core 4
Inner core 5

11. Lithosphere
Asthenosphere
Mesosphere
2 parts: rocky crust and rigid, outermost mantle
TECTONIC PLATES!!!!
Plastic (flowing) upper mantle directly beneath the lithosphere – Due to heat and pressure
Strong, dense lower layer of the mantle

12. Outer Core Inner Core molten Fe & Ni – produces Earth’s magnetic field
Surrounds Inner Core
Temperature = C
Less pressure than inner core
Inner Core
Solid Fe & Ni
Temperature = 5000oC
Extreme pressure
Why do you think the outer core is liquid, when the inner core is solid?
Intense pressure
makes it solid

14. Mapping the Earth’s Interior
When earthquakes occur, seismic body waves (P & S waves) are sent out in all directions, through the earth.
These vibrations reach different places at different times because of the ways the waves…
BEND and CHANGE SPEED
as they pass through Earth’s layers helping to ID the boundaries of the layers

15. Discovering Earth’s Layers