1. ENVIRONMENTAL SCIENCE CHAPTER 3
THE DYNAMIC EARTH

2. SECTION 1: THE GEOSPHERE

3. VOCABULARY GEOSPHERE CRUST MANTLE CORE LITHOSPHERE ASTHENOSPHERE
TECTONIC PLATE
EROSION

4. THE COMPOSITION OF EARTH
The Earth is composed of 3 major layers
Crust: less than 1% of earth’s mass, outer layer
Mantle: middle layer, makes up 64% of earth’s mass
Core: inner most layer, radius of 3,400 km
245 mya all land on Earth was joined in super continent Pangea

5. THE STRUCTURE OF EARTH 5 LAYERS
Lithosphere: divided into huge tectonic plates
Asthenosphere: slightly fluid layer beneath lithosphere…tectonic plates float on it
Mesosphere: “middle” sphere
Outer Core: made of liquid nickel and iron
Inner Core: solid nickel and iron

6. DISCUSSION
WHY IS IT IMPORTANT THAT ALL THE LAYERS OF THE EARTH MOVE EXCEPT THE CORE?
WHY IS IT THAT THE CORE AND THE CRUST ARE THE ONLY SOLID LAYERS ON THE EARTH?
WHY IS THIS IMPORTANT?

7. PLATE TECTONICS
Most of the geologic activity that happens on Earth occurs here
Plates are constantly moving on Earth’s surface
Separate…volcanoes
Collide…mountains
Slip…earthquakes

8. Recent Quakes

9. EROSION CAUSED BY WIND AND WATER
RIVERS AND OCEANS CAN CAUSE DRAMATIC CHANGES OF THE EARTH’S SURFACE
WIND CHANGES SOIL LEVELS
IF THERE ARE NO PLANTS TO HOLD SOIL DOWN WITH ROOTS, THEN SOIL BLOWS AWAY

11. SECTION 2: THE ATMOSPHERE

12. VOCABULARY ATMOSPHERE TROPOSPHERE STRATOSPHERE OZONE RADIATION
CONDUCTION
CONVECTION
GREENHOUSE EFFECT

13. COMPOSITION OF ATMOSPHERE
78% Nitrogen…comes from volcano eruption and plant/animal decay
21% Oxygen….comes from plant production
1% Other Gases…Argon, CO2, Methane, and Water Vapor
Also contains dust….dirt, salt, ash, skin, etc.
AIR PRESSURE: caused by gravity pulling atmosphere toward surface of Earth
How does air pressure change as the elevation change?

14. LAYERS OF ATMOSPHERE
TROPOSPHERE: layer nearest earth surface, almost all weather occurs in this layer
STRATOSPHERE: above troposphere, contains the ozone layer (protects us from UV rays)
MESOSPHERE: coldest layer of atmosphere
THERMOSPHERE: layer farthest away from earth surface, extremely high temperatures, first layer of defense against solar radiation

15. ENERGY IN ATMOSPHERE
CONDUCTION transfers heat from object to object and CONVECTION carries the heat in waves around the planet
Hot air rises….cold air sinks…causes weather
Solar energy heats the atmosphere…dark colors absorb heat, light colors reflect it
Air is constantly moving up and down due to convection currents

16. GREENHOUSE EFFECT
The gas in our atmosphere lets heat in, but not out….like a car and its windows
Some heat will escape the atmosphere, but most is absorbed by GREENHOUSE GASSES

17. SECTION 3:
THE HYDROSPHERE AND BIOSPHERE

18. VOCABULARY WATER CYCLE EVAPORATION CONDENSATION PRECIPITATION SALINITY
FRESH WATER
BIOSPHERE
CLOSED SYSTEM
OPEN SYSTEM

19. THE HYDROSPHERE & WATER CYCLE
HYDROSPHERE – includes all water on or near earth surface
WATER CYCLE – constant motion of water into air, onto land and back again
Evaporation, condensation & precipitation are 3 main steps

20. EARTH’S OCEANS 1 of 2 ALL OCEANS ARE CONNCETED
Make up 70% of Earth’s surface
Largest is the Pacific…Smallest is the Arctic
Ocean water is high in salt content…comes from rocks and volcanic eruptions
The deeper you go in the ocean the colder it gets….WHY?

21. Oceans are a temperature regulator
Absorbs and stores energy from the sun
Absorbs over ½ of the solar radiation that reaches the surface
Ocean currents are responsible for localized weather
If an area has warm ocean currents then they will have warmer weather
If an area has cool/cold ocean currents then they will have cool/cold weather

24. FRESH WATER & GROUND WATER
Little more than 3% of water on earth is fresh water…mostly locked up in icecaps and glaciers
Made up of river systems…interconnected rivers and tributaries
Precipitation sinks into ground and collects as ground water in rock layers called AQUIFERS

25. THE BIOSPHERE
Earth compared to apple…biosphere compared to apple skin…small layer of Earth that actually supports life
Biosphere located near Earth’s surface because most of sunlight is available at Earth’s surface

26. ENERGY FLOW IN BIOSPHERE
CLOSED SYSTEM: energy enters environment, matter does not
Earth mostly closed system to matter, but open system to energy
FOOD CHAINS/WEBS
OPEN SYSTEM: both matter and energy are exchanged