1. Structure of the Earth

2. Compositional Zones Earth has 2 types of layers or zones: QUESTION:
Compositional: what each layer is made of
Mechanical or Structural: physical characteristics about each layer, and how they respond to stress
QUESTION:
Look at this picture and describe how both sides individually classify the layers of the Earth.

3. Crust <1% of Earth’s mass Earth’s crust is the thinnest layer.
Oceanic
Made mostly of igneous basalt
Thin: 5-7 km
Contains more iron than continental crust. MAFIC
Earth’s crust is the thinnest layer.
5-100 km thick
Two types of crust :
Oceanic
Continental
Continental
Found under continents.
Thick: up to 100 km
Made mostly of granite. FELSIC

4. QUESTION:
Look at this picture and describe which type of crust (oceanic or continental) is the most dense and why.

5. Mantle 68% of Earth’s mass
Earth’s mantle is directly above the outer core and starts blow the crust. It is the largest layer and relatively homogeneous. It is made of more iron than the crust. Density, pressure, and temperature all increase the deeper you go in the mantle. Heat is transferred through convection.
QUESTION:
Explain what you think is happening in the green layer above the mantle.

6. Core 31% of Earth’s mass The core has two parts: Inner Outer
The outer core is liquid and surrounds the solid inner core.
The outer core is made of molten iron and nickel.
The inner core is solid iron and nickel.
QUESTION:
Explain what this picture is demonstrating and how it relates to the core.

7. Structural/Mechanical Zones
Structural Zones are often thought of their characteristic response to stress.

8. Lithosphere Rigid layer The lithosphere is made up of 2 parts:
Crust
Rigid ‘Upper Mantle’
It is divided into tectonic plates.
QUESTION:
Do you think the tectonic plates consist of oceanic, or continental crust, or both.

9. Asthenosphere Plastic layer The Asthenosphere is made up of:
QUESTION:
How does the plasticity in the asthenosphere play a role in plate tectonics?
The Asthenosphere is made up of:
Plastic ‘Upper Mantle’
Plasticity is when a solid rock flows very slowly due to heat and pressure.
This is the layer on which tectonic plates move.

11. Mesosphere Strong layer ‘Lower Mantle’ The mesosphere is made up of:
Comparison to ‘Upper Mantle’
Greater density
More rigid
Same chemical composition
QUESTION:
As you increase depth in the mantle, what else happens?