1. Geology and Earth’s Structure

2. Leave enough space between each title to write notes!!!
On your foldable underneath each picture of the layer please write the following titles for your notes:
Composition
Thickness
Temperature
State of Matter
Other facts
Leave enough space between each title to write notes!!!

3. The Science of Geology Geology Geologists
The study of planet Earth, including its origin, history, composition
Physical and Historical
Geologists
Scientists who study Earth and the processes that have shaped Earth over time

4. Earth’s Four Spheres Atmosphere Hydrosphere Geosphere Biosphere
Blanket of gases that surrounds the Earth’s surface
Hydrosphere
All the Earth’s water with the exception of water in the gaseous form
71% or Earth’s surface is water
97% is salt water found in the oceans and 3% is fresh water found in lakes, rivers, streams, glaciers, ice sheets, and ground water
Geosphere
Solid part of the Earth that includes all of the rocks and soil
Also includes the solid and molten interior of the Earth
Biosphere
All the life forms found within the other three spheres
Includes any organic matter that has NOT completely decomposed

5. Forces that Change Earth’s Surface
Constructive Forces
shape the surface by building up mountains and other land areas
Destructive Forces
slowly wear away mountains and eventually every other feature on Earth’s surface

6. Uniformitarianism
The principal of uniformitarianism states that the processes affecting Earth today are the same ones that affected it in the past
Example- at active volcanoes we can observe lava cooling to form layers of basalt
Therefore, any time we see layers of basalt, we can assume that they formed from cooling lava

7. The Earth as we normally see it

8. Our Understanding
Scientists use indirect methods to study the Earth’s interior
Seismic waves- vibrations that travels through the earth
Caused by earthquakes

9. A Cross Section of the Earth
Earth is divided into four main layers
1. Crust
2. Mantle
3. Outer Core
4. Inner core …
Similar to the cross section of a hard boiled egg

10. A Cross Section of the Earth
Which of these layers holds life? Think about it…where do we live? …
Similar to the cross section of a hard boiled egg

11. The Crust SOLID Outermost layer on which life exists Thinnest layer
Composition: Covered in soil, rock (silicates), and water
Thinnest layer
The Earth's Crust is like the skin of an apple
The crust is thickest under the continents and thinnest under the oceans
Thickness: 5 to 64 kilometers (thinner in the oceans)
Temperature
Varies from air temp on the surface to 870° C in the deepest part of the crust

12. Types of Crusts (Make a T-chart in your foldable)
Oceanic Crust
Rock that makes up the ocean floor
Made of more dense rock (basalt)
Average thickness: only 7 km
Ranges from 5-10 km
Continental Crust
Rock that makes up the continents
Made of less dense rock (granite)
Average thickness: 40 km
Ranges from 8-75 km

13. The Crust The crust “floats” on the mantle because it is less dense
Think of oil and water
It is broken into sections called tectonic plates
These plates move very slowly
Results in the physical features found on the surface
These plates move because of convection currents

14. Convection Currents
Caused by the very hot material at the deepest part of the mantle rising, then cooling and sinking and then heating and rising again
A conveyor belt in a factory moves boxes like the convection currents in the mantle moves the plates of the Earth

15. The Mantle Hot but SOLID rock that flows (plastic) Composition:
Thickness: Approximately 2850 km thick
Thickest of all Earths layers approximately ~85% of the Earth's volume
Composition:
Composed of minerals rich in Fe, Mg, Si, and O (silicates)
Considered solid but has plasticity
Rock can flow like a thick liquid
Temperature
Varies from 870°Cto 2200 °C

16. Three Divisions of the Mantle
1. Lithosphere- layer of relatively cool, rigid rock
Includes the uppermost part of the mantle and the Earth’s crust (100 km thick)
Broken into plates
2. Asthenosphere- (middle mantle) layer of softer, weaker rock that can flow like taffy (plastic)
Produces magma
3. Mesosphere- (lower mantle) stronger layer made of stiff rock that extends to the upper surface of the core

20. The Outer Core LIQUID Thickness: Approximately 2270 km thick
Composition: Consists mostly of the liquid metals iron and nickel
16% of the Earth's total volume
Temperature
Ranges from 2200° C to 4982°C
Flowing iron of outer core produces electric current and creates the Earth’s magnetic field

21. The Inner Core SOLID Thickness: Approximately 1216 km thick
Composition: Consists of solid nickel-iron alloy
Temperature
Stays around 4982° C
Pressures are 45,000,000 pounds per square inch
This is 3,000,000 times the air pressure on you at sea level!!!
If you were to make it to the center of the Earth you would be squished into the size of a marble

22. How the Earth is Represented Visually

23. Side by Side Comparison
Crust
Mantle
Core
Lithosphere
Asthenosphere
Mesosphere
Outer Core
Inner Core

25. Density, Pressure, and Temperature
Density, pressure, and temperature ALL INCREASE as you go further into the Earth’s layers