1. Land, Water, and Air
2.2

2. Lithosphere Earth’s solid surface and interior
Includes the crust, mantle, and core
The crust and top layer of mantle are divided into huge, irregular-shaped slabs of rock called plates

3. Plate Tectonics
Scientists believe Earth’s surface cracked into plates millions of years ago
These plates have been moving and shifting
This theory is known as plate tectonics

4. Continental Drift
Plate tectonics is a theory that helps explain continental drift
Continental drift is a theory of how continents move over time
Today, Earth has 12 major plates and hundreds of smaller ones

5. Plate Movement
Mountains form when plates bump into each other and push upward
Earthquakes occur when two plates slide past each other, catch and create tension
Eventually the tension is released and the ground shakes

6. Plate Movement (cont.) Volcanoes form along the edges of plates
Hot rock from inside the earth oozes or explodes then flows onto surrounding land/ocean floor
Plate movement has also created the Earth’s continents

7. Hydrosphere Earth’s liquid layer where water is found
Includes all the water on Earth:
Oceans
Ponds
Lakes
Streams
Groundwater
Water in the air that forms clouds

8. Water Covers about 70% of Earth’s surface Necessary for life
Humans are 50-75% water
Helps chemical reactions take place (allows organisms to grow, digest food, and sweat)

9. Water (cont.)
Helps the Earth remain at temperatures that can support life (water absorbs and releases heat)
Earth is the only planet that has water in liquid form
Other planets have ice or water vapor

10. Atmosphere Layer of air that surrounds Earth
Contains a mixture of gases; nitrogen and oxygen
Made up of four layers

11. Layers of Earth’s Atmosphere
Troposphere 0-16km above Earth
layer where people live and breathe; also where weather happens
Stratosphere (16-50km above Earth)
Mesosphere (50-80km above Earth)
Thermosphere (80-480km above Earth)

12. Atmosphere Layers
The farther a layer is from the Earth’s surface, the colder and thinner the air is
Act as protective blankets of air
Allows some of the sun’s rays to reach the Earth
Keeps warmth in at nighttime

13. Ozone and UV The ozone layer is located in the stratosphere
It absorbs most of the harmful ultraviolet radiation produced by the sun
Ultraviolet radiation is a part of sunlight
Small amounts help your skin make vitamin D
Vitamin D helps your skin, eyesight, bone and tooth growth
Too much can burn you, cause skin damage, cancer

14. Assignment Science in your Life
Consumer Choices: Choosing Sun Protecting
Pg. 53
#1-3
Turn in

15. Vocabulary Plate Tectonics Continental Drift Ozone Layer Lithosphere
Atmosphere
Hydrosphere
Biosphere